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Merge pull request #281 from ankurkaushal/master

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Reformat according to google style guide
This commit is contained in:
Ilkka Seppälä 2015-11-02 21:39:17 +02:00
commit fe63c9cec4
438 changed files with 8257 additions and 8382 deletions
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138
abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java
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@ -3,80 +3,78 @@ package com.iluwatar.abstractfactory;
/**
*
* The Abstract Factory pattern provides a way to encapsulate a group of individual
* factories that have a common theme without specifying their concrete classes. In
* normal usage, the client software creates a concrete implementation of the abstract
* factory and then uses the generic interface of the factory to create the concrete
* objects that are part of the theme. The client does not know (or care) which
* concrete objects it gets from each of these internal factories, since it uses only
* the generic interfaces of their products. This pattern separates the details of
* implementation of a set of objects from their general usage and relies on object
* composition, as object creation is implemented in methods exposed in the factory
* interface.
* The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
* have a common theme without specifying their concrete classes. In normal usage, the client
* software creates a concrete implementation of the abstract factory and then uses the generic
* interface of the factory to create the concrete objects that are part of the theme. The client
* does not know (or care) which concrete objects it gets from each of these internal factories,
* since it uses only the generic interfaces of their products. This pattern separates the details
* of implementation of a set of objects from their general usage and relies on object composition,
* as object creation is implemented in methods exposed in the factory interface.
* <p>
* The essence of the Abstract Factory pattern is a factory interface
* ({@link KingdomFactory}) and its implementations ({@link ElfKingdomFactory},
* {@link OrcKingdomFactory}). The example uses both concrete implementations to
* create a king, a castle and an army.
* The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and
* its implementations ({@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both
* concrete implementations to create a king, a castle and an army.
*
*/
public class App {
private King king;
private Castle castle;
private Army army;
private King king;
private Castle castle;
private Army army;
/**
* Creates kingdom
* @param factory
*/
public void createKingdom(final KingdomFactory factory) {
setKing(factory.createKing());
setCastle(factory.createCastle());
setArmy(factory.createArmy());
}
ElfKingdomFactory getElfKingdomFactory() {
return new ElfKingdomFactory();
}
OrcKingdomFactory getOrcKingdomFactory() {
return new OrcKingdomFactory();
}
King getKing(final KingdomFactory factory) {
return factory.createKing();
}
Castle getCastle(final KingdomFactory factory) {
return factory.createCastle();
}
Army getArmy(final KingdomFactory factory) {
return factory.createArmy();
}
public King getKing() {
return king;
}
private void setKing(final King king) {
this.king = king;
}
public Castle getCastle() {
return castle;
}
private void setCastle(final Castle castle) {
this.castle = castle;
}
public Army getArmy() {
return army;
}
private void setArmy(final Army army) {
this.army = army;
}
/**
* Creates kingdom
*
* @param factory
*/
public void createKingdom(final KingdomFactory factory) {
setKing(factory.createKing());
setCastle(factory.createCastle());
setArmy(factory.createArmy());
}
ElfKingdomFactory getElfKingdomFactory() {
return new ElfKingdomFactory();
}
OrcKingdomFactory getOrcKingdomFactory() {
return new OrcKingdomFactory();
}
King getKing(final KingdomFactory factory) {
return factory.createKing();
}
Castle getCastle(final KingdomFactory factory) {
return factory.createCastle();
}
Army getArmy(final KingdomFactory factory) {
return factory.createArmy();
}
public King getKing() {
return king;
}
private void setKing(final King king) {
this.king = king;
}
public Castle getCastle() {
return castle;
}
private void setCastle(final Castle castle) {
this.castle = castle;
}
public Army getArmy() {
return army;
}
private void setArmy(final Army army) {
this.army = army;
}
}

2
abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java
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@ -7,5 +7,5 @@ package com.iluwatar.abstractfactory;
*/
public interface Army {
String getDescription();
String getDescription();
}

2
abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java
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@ -7,5 +7,5 @@ package com.iluwatar.abstractfactory;
*/
public interface Castle {
String getDescription();
String getDescription();
}

10
abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class ElfArmy implements Army {
static final String DESCRIPTION = "This is the Elven Army!";
static final String DESCRIPTION = "This is the Elven Army!";
@Override
public String getDescription() {
return DESCRIPTION;
}
@Override
public String getDescription() {
return DESCRIPTION;
}
}

10
abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class ElfCastle implements Castle {
static final String DESCRIPTION = "This is the Elven castle!";
static final String DESCRIPTION = "This is the Elven castle!";
@Override
public String getDescription() {
return DESCRIPTION;
}
@Override
public String getDescription() {
return DESCRIPTION;
}
}

12
abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class ElfKing implements King {
static final String DESCRIPTION = "This is the Elven king!";
@Override
public String getDescription() {
return DESCRIPTION;
}
static final String DESCRIPTION = "This is the Elven king!";
@Override
public String getDescription() {
return DESCRIPTION;
}
}

18
abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java
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@ -7,16 +7,16 @@ package com.iluwatar.abstractfactory;
*/
public class ElfKingdomFactory implements KingdomFactory {
public Castle createCastle() {
return new ElfCastle();
}
public Castle createCastle() {
return new ElfCastle();
}
public King createKing() {
return new ElfKing();
}
public King createKing() {
return new ElfKing();
}
public Army createArmy() {
return new ElfArmy();
}
public Army createArmy() {
return new ElfArmy();
}
}

2
abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java
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@ -7,5 +7,5 @@ package com.iluwatar.abstractfactory;
*/
public interface King {
String getDescription();
String getDescription();
}

6
abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public interface KingdomFactory {
Castle createCastle();
Castle createCastle();
King createKing();
King createKing();
Army createArmy();
Army createArmy();
}

10
abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class OrcArmy implements Army {
static final String DESCRIPTION = "This is the Orc Army!";
static final String DESCRIPTION = "This is the Orc Army!";
@Override
public String getDescription() {
return DESCRIPTION;
}
@Override
public String getDescription() {
return DESCRIPTION;
}
}

10
abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class OrcCastle implements Castle {
static final String DESCRIPTION = "This is the Orc castle!";
static final String DESCRIPTION = "This is the Orc castle!";
@Override
public String getDescription() {
return DESCRIPTION;
}
@Override
public String getDescription() {
return DESCRIPTION;
}
}

12
abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java
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@ -7,10 +7,10 @@ package com.iluwatar.abstractfactory;
*/
public class OrcKing implements King {
static final String DESCRIPTION = "This is the Orc king!";
@Override
public String getDescription() {
return DESCRIPTION;
}
static final String DESCRIPTION = "This is the Orc king!";
@Override
public String getDescription() {
return DESCRIPTION;
}
}

19
abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java
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@ -7,16 +7,15 @@ package com.iluwatar.abstractfactory;
*/
public class OrcKingdomFactory implements KingdomFactory {
public Castle createCastle() {
return new OrcCastle();
}
public Castle createCastle() {
return new OrcCastle();
}
public King createKing() {
return new OrcKing();
}
public Army createArmy() {
return new OrcArmy();
}
public King createKing() {
return new OrcKing();
}
public Army createArmy() {
return new OrcArmy();
}
}

135
abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java
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@ -1,4 +1,5 @@
package com.iluwatar.abstractfactory;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
@ -7,71 +8,71 @@ import org.junit.Test;
public class AppTest {
private App app = new App();
private KingdomFactory elfFactory;
private KingdomFactory orcFactory;
@Before
public void setUp() {
elfFactory = app.getElfKingdomFactory();
orcFactory = app.getOrcKingdomFactory();
}
@Test
public void king() {
final King elfKing = app.getKing(elfFactory);
assertTrue(elfKing instanceof ElfKing);
assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
final King orcKing = app.getKing(orcFactory);
assertTrue(orcKing instanceof OrcKing);
assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
}
@Test
public void castle() {
final Castle elfCastle = app.getCastle(elfFactory);
assertTrue(elfCastle instanceof ElfCastle);
assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
final Castle orcCastle = app.getCastle(orcFactory);
assertTrue(orcCastle instanceof OrcCastle);
assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
}
@Test
public void army() {
final Army elfArmy = app.getArmy(elfFactory);
assertTrue(elfArmy instanceof ElfArmy);
assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
final Army orcArmy = app.getArmy(orcFactory);
assertTrue(orcArmy instanceof OrcArmy);
assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
}
@Test
public void createElfKingdom() {
app.createKingdom(elfFactory);
final King king = app.getKing();
final Castle castle = app.getCastle();
final Army army = app.getArmy();
assertTrue(king instanceof ElfKing);
assertEquals(ElfKing.DESCRIPTION, king.getDescription());
assertTrue(castle instanceof ElfCastle);
assertEquals(ElfCastle.DESCRIPTION, castle.getDescription());
assertTrue(army instanceof ElfArmy);
assertEquals(ElfArmy.DESCRIPTION, army.getDescription());
}
@Test
public void createOrcKingdom() {
app.createKingdom(orcFactory);
final King king = app.getKing();
final Castle castle = app.getCastle();
final Army army = app.getArmy();
assertTrue(king instanceof OrcKing);
assertEquals(OrcKing.DESCRIPTION, king.getDescription());
assertTrue(castle instanceof OrcCastle);
assertEquals(OrcCastle.DESCRIPTION, castle.getDescription());
assertTrue(army instanceof OrcArmy);
assertEquals(OrcArmy.DESCRIPTION, army.getDescription());
}
private App app = new App();
private KingdomFactory elfFactory;
private KingdomFactory orcFactory;
@Before
public void setUp() {
elfFactory = app.getElfKingdomFactory();
orcFactory = app.getOrcKingdomFactory();
}
@Test
public void king() {
final King elfKing = app.getKing(elfFactory);
assertTrue(elfKing instanceof ElfKing);
assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
final King orcKing = app.getKing(orcFactory);
assertTrue(orcKing instanceof OrcKing);
assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
}
@Test
public void castle() {
final Castle elfCastle = app.getCastle(elfFactory);
assertTrue(elfCastle instanceof ElfCastle);
assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
final Castle orcCastle = app.getCastle(orcFactory);
assertTrue(orcCastle instanceof OrcCastle);
assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
}
@Test
public void army() {
final Army elfArmy = app.getArmy(elfFactory);
assertTrue(elfArmy instanceof ElfArmy);
assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
final Army orcArmy = app.getArmy(orcFactory);
assertTrue(orcArmy instanceof OrcArmy);
assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
}
@Test
public void createElfKingdom() {
app.createKingdom(elfFactory);
final King king = app.getKing();
final Castle castle = app.getCastle();
final Army army = app.getArmy();
assertTrue(king instanceof ElfKing);
assertEquals(ElfKing.DESCRIPTION, king.getDescription());
assertTrue(castle instanceof ElfCastle);
assertEquals(ElfCastle.DESCRIPTION, castle.getDescription());
assertTrue(army instanceof ElfArmy);
assertEquals(ElfArmy.DESCRIPTION, army.getDescription());
}
@Test
public void createOrcKingdom() {
app.createKingdom(orcFactory);
final King king = app.getKing();
final Castle castle = app.getCastle();
final Army army = app.getArmy();
assertTrue(king instanceof OrcKing);
assertEquals(OrcKing.DESCRIPTION, king.getDescription());
assertTrue(castle instanceof OrcCastle);
assertEquals(OrcCastle.DESCRIPTION, castle.getDescription());
assertTrue(army instanceof OrcArmy);
assertEquals(OrcArmy.DESCRIPTION, army.getDescription());
}
}

39
adapter/src/main/java/com/iluwatar/adapter/App.java
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@ -2,30 +2,29 @@ package com.iluwatar.adapter;
/**
*
* An adapter helps two incompatible interfaces to work together. This is the real
* world definition for an adapter. Interfaces may be incompatible but the inner
* functionality should suit the need. The Adapter design pattern allows otherwise
* incompatible classes to work together by converting the interface of one class
* into an interface expected by the clients.
* An adapter helps two incompatible interfaces to work together. This is the real world definition
* for an adapter. Interfaces may be incompatible but the inner functionality should suit the need.
* The Adapter design pattern allows otherwise incompatible classes to work together by converting
* the interface of one class into an interface expected by the clients.
* <p>
* There are two variations of the Adapter pattern: The class adapter implements
* the adaptee's interface whereas the object adapter uses composition to
* contain the adaptee in the adapter object. This example uses the object
* adapter approach.
* There are two variations of the Adapter pattern: The class adapter implements the adaptee's
* interface whereas the object adapter uses composition to contain the adaptee in the adapter
* object. This example uses the object adapter approach.
* <p>
* The Adapter ({@link GnomeEngineer}) converts the interface of the target class
* ({@link GoblinGlider}) into a suitable one expected by the client
* ({@link GnomeEngineeringManager}).
* The Adapter ({@link GnomeEngineer}) converts the interface of the target class (
* {@link GoblinGlider}) into a suitable one expected by the client ({@link GnomeEngineeringManager}
* ).
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
Engineer manager = new GnomeEngineeringManager();
manager.operateDevice();
}
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
Engineer manager = new GnomeEngineeringManager();
manager.operateDevice();
}
}

3
adapter/src/main/java/com/iluwatar/adapter/Engineer.java
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@ -7,6 +7,5 @@ package com.iluwatar.adapter;
*/
public interface Engineer {
void operateDevice();
void operateDevice();
}

25
adapter/src/main/java/com/iluwatar/adapter/GnomeEngineer.java
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@ -2,23 +2,22 @@ package com.iluwatar.adapter;
/**
*
* Adapter class. Adapts the interface of the device ({@link GoblinGlider}) into
* {@link Engineer} interface expected by the client ({@link GnomeEngineeringManager}).
* Adapter class. Adapts the interface of the device ({@link GoblinGlider}) into {@link Engineer}
* interface expected by the client ({@link GnomeEngineeringManager}).
*
*/
public class GnomeEngineer implements Engineer {
private GoblinGlider glider;
private GoblinGlider glider;
public GnomeEngineer() {
glider = new GoblinGlider();
}
@Override
public void operateDevice() {
glider.attachGlider();
glider.gainSpeed();
glider.takeOff();
}
public GnomeEngineer() {
glider = new GoblinGlider();
}
@Override
public void operateDevice() {
glider.attachGlider();
glider.gainSpeed();
glider.takeOff();
}
}

16
adapter/src/main/java/com/iluwatar/adapter/GnomeEngineeringManager.java
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@ -7,14 +7,14 @@ package com.iluwatar.adapter;
*/
public class GnomeEngineeringManager implements Engineer {
private Engineer engineer;
private Engineer engineer;
public GnomeEngineeringManager() {
engineer = new GnomeEngineer();
}
public GnomeEngineeringManager() {
engineer = new GnomeEngineer();
}
@Override
public void operateDevice() {
engineer.operateDevice();
}
@Override
public void operateDevice() {
engineer.operateDevice();
}
}

18
adapter/src/main/java/com/iluwatar/adapter/GoblinGlider.java
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@ -7,15 +7,15 @@ package com.iluwatar.adapter;
*/
public class GoblinGlider {
public void attachGlider() {
System.out.println("Glider attached.");
}
public void attachGlider() {
System.out.println("Glider attached.");
}
public void gainSpeed() {
System.out.println("Gaining speed.");
}
public void gainSpeed() {
System.out.println("Gaining speed.");
}
public void takeOff() {
System.out.println("Lift-off!");
}
public void takeOff() {
System.out.println("Lift-off!");
}
}

10
adapter/src/test/java/com/iluwatar/adapter/AppTest.java
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@ -11,9 +11,9 @@ import com.iluwatar.adapter.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

139
async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java
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@ -4,23 +4,24 @@ import java.util.concurrent.Callable;
/**
* This application demonstrates the async method invocation pattern. Key parts of the pattern are
* <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated value,
* <code>AsyncCallback</code> which can be provided to be executed on task completion and
* <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated
* value, <code>AsyncCallback</code> which can be provided to be executed on task completion and
* <code>AsyncExecutor</code> that manages the execution of the async tasks.
* <p>
* The main method shows example flow of async invocations. The main thread starts multiple tasks with
* variable durations and then continues its own work. When the main thread has done it's job it collects
* the results of the async tasks. Two of the tasks are handled with callbacks, meaning the callbacks are
* executed immediately when the tasks complete.
* The main method shows example flow of async invocations. The main thread starts multiple tasks
* with variable durations and then continues its own work. When the main thread has done it's job
* it collects the results of the async tasks. Two of the tasks are handled with callbacks, meaning
* the callbacks are executed immediately when the tasks complete.
* <p>
* Noteworthy difference of thread usage between the async results and callbacks is that the async results
* are collected in the main thread but the callbacks are executed within the worker threads. This should be
* noted when working with thread pools.
* Noteworthy difference of thread usage between the async results and callbacks is that the async
* results are collected in the main thread but the callbacks are executed within the worker
* threads. This should be noted when working with thread pools.
* <p>
* Java provides its own implementations of async method invocation pattern. FutureTask, CompletableFuture
* and ExecutorService are the real world implementations of this pattern. But due to the nature of parallel
* programming, the implementations are not trivial. This example does not take all possible scenarios into
* account but rather provides a simple version that helps to understand the pattern.
* Java provides its own implementations of async method invocation pattern. FutureTask,
* CompletableFuture and ExecutorService are the real world implementations of this pattern. But due
* to the nature of parallel programming, the implementations are not trivial. This example does not
* take all possible scenarios into account but rather provides a simple version that helps to
* understand the pattern.
*
* @see AsyncResult
* @see AsyncCallback
@ -32,66 +33,68 @@ import java.util.concurrent.Callable;
*/
public class App {
public static void main(String[] args) throws Exception {
// construct a new executor that will run async tasks
AsyncExecutor executor = new ThreadAsyncExecutor();
public static void main(String[] args) throws Exception {
// construct a new executor that will run async tasks
AsyncExecutor executor = new ThreadAsyncExecutor();
// start few async tasks with varying processing times, two last with callback handlers
AsyncResult<Integer> asyncResult1 = executor.startProcess(lazyval(10, 500));
AsyncResult<String> asyncResult2 = executor.startProcess(lazyval("test", 300));
AsyncResult<Long> asyncResult3 = executor.startProcess(lazyval(50L, 700));
AsyncResult<Integer> asyncResult4 = executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
AsyncResult<String> asyncResult5 = executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
// start few async tasks with varying processing times, two last with callback handlers
AsyncResult<Integer> asyncResult1 = executor.startProcess(lazyval(10, 500));
AsyncResult<String> asyncResult2 = executor.startProcess(lazyval("test", 300));
AsyncResult<Long> asyncResult3 = executor.startProcess(lazyval(50L, 700));
AsyncResult<Integer> asyncResult4 =
executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
AsyncResult<String> asyncResult5 =
executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
// emulate processing in the current thread while async tasks are running in their own threads
Thread.sleep(350); // Oh boy I'm working hard here
log("Some hard work done");
// emulate processing in the current thread while async tasks are running in their own threads
Thread.sleep(350); // Oh boy I'm working hard here
log("Some hard work done");
// wait for completion of the tasks
Integer result1 = executor.endProcess(asyncResult1);
String result2 = executor.endProcess(asyncResult2);
Long result3 = executor.endProcess(asyncResult3);
asyncResult4.await();
asyncResult5.await();
// wait for completion of the tasks
Integer result1 = executor.endProcess(asyncResult1);
String result2 = executor.endProcess(asyncResult2);
Long result3 = executor.endProcess(asyncResult3);
asyncResult4.await();
asyncResult5.await();
// log the results of the tasks, callbacks log immediately when complete
log("Result 1: " + result1);
log("Result 2: " + result2);
log("Result 3: " + result3);
}
// log the results of the tasks, callbacks log immediately when complete
log("Result 1: " + result1);
log("Result 2: " + result2);
log("Result 3: " + result3);
}
/**
* Creates a callable that lazily evaluates to given value with artificial delay.
*
* @param value value to evaluate
* @param delayMillis artificial delay in milliseconds
* @return new callable for lazy evaluation
*/
private static <T> Callable<T> lazyval(T value, long delayMillis) {
return () -> {
Thread.sleep(delayMillis);
log("Task completed with: " + value);
return value;
};
}
/**
* Creates a callable that lazily evaluates to given value with artificial delay.
*
* @param value value to evaluate
* @param delayMillis artificial delay in milliseconds
* @return new callable for lazy evaluation
*/
private static <T> Callable<T> lazyval(T value, long delayMillis) {
return () -> {
Thread.sleep(delayMillis);
log("Task completed with: " + value);
return value;
};
}
/**
* Creates a simple callback that logs the complete status of the async result.
*
* @param name callback name
* @return new async callback
*/
private static <T> AsyncCallback<T> callback(String name) {
return (value, ex) -> {
if (ex.isPresent()) {
log(name + " failed: " + ex.map(Exception::getMessage).orElse(""));
} else {
log(name + ": " + value);
}
};
}
/**
* Creates a simple callback that logs the complete status of the async result.
*
* @param name callback name
* @return new async callback
*/
private static <T> AsyncCallback<T> callback(String name) {
return (value, ex) -> {
if (ex.isPresent()) {
log(name + " failed: " + ex.map(Exception::getMessage).orElse(""));
} else {
log(name + ": " + value);
}
};
}
private static void log(String msg) {
System.out.println(String.format("[%1$-10s] - %2$s", Thread.currentThread().getName(), msg));
}
private static void log(String msg) {
System.out.println(String.format("[%1$-10s] - %2$s", Thread.currentThread().getName(), msg));
}
}

15
async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/AsyncCallback.java
View File

@ -11,12 +11,11 @@ import java.util.Optional;
*/
public interface AsyncCallback<T> {
/**
* Complete handler which is executed when async task is completed or fails execution.
*
* @param value the evaluated value from async task, undefined when execution fails
* @param ex empty value if execution succeeds, some exception if executions fails
*/
void onComplete(T value, Optional<Exception> ex);
/**
* Complete handler which is executed when async task is completed or fails execution.
*
* @param value the evaluated value from async task, undefined when execution fails
* @param ex empty value if execution succeeds, some exception if executions fails
*/
void onComplete(T value, Optional<Exception> ex);
}

53
async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/AsyncExecutor.java
View File

@ -10,33 +10,32 @@ import java.util.concurrent.ExecutionException;
*/
public interface AsyncExecutor {
/**
* Starts processing of an async task. Returns immediately with async result.
*
* @param task task to be executed asynchronously
* @return async result for the task
*/
<T> AsyncResult<T> startProcess(Callable<T> task);
/**
* Starts processing of an async task. Returns immediately with async result.
*
* @param task task to be executed asynchronously
* @return async result for the task
*/
<T> AsyncResult<T> startProcess(Callable<T> task);
/**
* Starts processing of an async task. Returns immediately with async result. Executes callback
* when the task is completed.
*
* @param task task to be executed asynchronously
* @param callback callback to be executed on task completion
* @return async result for the task
*/
<T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback);
/**
* Ends processing of an async task. Blocks the current thread if necessary and returns the
* evaluated value of the completed task.
*
* @param asyncResult async result of a task
* @return evaluated value of the completed task
* @throws ExecutionException if execution has failed, containing the root cause
* @throws InterruptedException if the execution is interrupted
*/
<T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException;
/**
* Starts processing of an async task. Returns immediately with async result. Executes callback
* when the task is completed.
*
* @param task task to be executed asynchronously
* @param callback callback to be executed on task completion
* @return async result for the task
*/
<T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback);
/**
* Ends processing of an async task. Blocks the current thread if necessary and returns the
* evaluated value of the completed task.
*
* @param asyncResult async result of a task
* @return evaluated value of the completed task
* @throws ExecutionException if execution has failed, containing the root cause
* @throws InterruptedException if the execution is interrupted
*/
<T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException;
}

40
async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/AsyncResult.java
View File

@ -10,26 +10,26 @@ import java.util.concurrent.ExecutionException;
*/
public interface AsyncResult<T> {
/**
* Status of the async task execution.
*
* @return <code>true</code> if execution is completed or failed
*/
boolean isCompleted();
/**
* Status of the async task execution.
*
* @return <code>true</code> if execution is completed or failed
*/
boolean isCompleted();
/**
* Gets the value of completed async task.
*
* @return evaluated value or throws ExecutionException if execution has failed
* @throws ExecutionException if execution has failed, containing the root cause
* @throws IllegalStateException if execution is not completed
*/
T getValue() throws ExecutionException;
/**
* Gets the value of completed async task.
*
* @return evaluated value or throws ExecutionException if execution has failed
* @throws ExecutionException if execution has failed, containing the root cause
* @throws IllegalStateException if execution is not completed
*/
T getValue() throws ExecutionException;
/**
* Blocks the current thread until the async task is completed.
*
* @throws InterruptedException if the execution is interrupted
*/
void await() throws InterruptedException;
/**
* Blocks the current thread until the async task is completed.
*
* @throws InterruptedException if the execution is interrupted
*/
void await() throws InterruptedException;
}

199
async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/ThreadAsyncExecutor.java
View File

@ -12,116 +12,117 @@ import java.util.concurrent.atomic.AtomicInteger;
*/
public class ThreadAsyncExecutor implements AsyncExecutor {
/** Index for thread naming */
private final AtomicInteger idx = new AtomicInteger(0);
/** Index for thread naming */
private final AtomicInteger idx = new AtomicInteger(0);
@Override
public <T> AsyncResult<T> startProcess(Callable<T> task) {
return startProcess(task, null);
}
@Override
public <T> AsyncResult<T> startProcess(Callable<T> task) {
return startProcess(task, null);
}
@Override
public <T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback) {
CompletableResult<T> result = new CompletableResult<>(callback);
new Thread(() -> {
try {
result.setValue(task.call());
} catch (Exception ex) {
result.setException(ex);
}
}, "executor-" + idx.incrementAndGet()).start();
return result;
}
@Override
public <T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback) {
CompletableResult<T> result = new CompletableResult<>(callback);
new Thread(() -> {
try {
result.setValue(task.call());
} catch (Exception ex) {
result.setException(ex);
}
}, "executor-" + idx.incrementAndGet()).start();
return result;
}
@Override
public <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException {
if (asyncResult.isCompleted()) {
return asyncResult.getValue();
} else {
asyncResult.await();
return asyncResult.getValue();
}
}
@Override
public <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException,
InterruptedException {
if (asyncResult.isCompleted()) {
return asyncResult.getValue();
} else {
asyncResult.await();
return asyncResult.getValue();
}
}
/**
* Simple implementation of async result that allows completing it successfully with a value
* or exceptionally with an exception. A really simplified version from its real life cousins
* FutureTask and CompletableFuture.
*
* @see java.util.concurrent.FutureTask
* @see java.util.concurrent.CompletableFuture
*/
private static class CompletableResult<T> implements AsyncResult<T> {
/**
* Simple implementation of async result that allows completing it successfully with a value or
* exceptionally with an exception. A really simplified version from its real life cousins
* FutureTask and CompletableFuture.
*
* @see java.util.concurrent.FutureTask
* @see java.util.concurrent.CompletableFuture
*/
private static class CompletableResult<T> implements AsyncResult<T> {
static final int RUNNING = 1;
static final int FAILED = 2;
static final int COMPLETED = 3;
static final int RUNNING = 1;
static final int FAILED = 2;
static final int COMPLETED = 3;
final Object lock;
final Optional<AsyncCallback<T>> callback;
final Object lock;
final Optional<AsyncCallback<T>> callback;
volatile int state = RUNNING;
T value;
Exception exception;
volatile int state = RUNNING;
T value;
Exception exception;
CompletableResult(AsyncCallback<T> callback) {
this.lock = new Object();
this.callback = Optional.ofNullable(callback);
}
CompletableResult(AsyncCallback<T> callback) {
this.lock = new Object();
this.callback = Optional.ofNullable(callback);
}
/**
* Sets the value from successful execution and executes callback if available. Notifies
* any thread waiting for completion.
*
* @param value value of the evaluated task
*/
void setValue(T value) {
this.value = value;
this.state = COMPLETED;
this.callback.ifPresent(ac -> ac.onComplete(value, Optional.<Exception>empty()));
synchronized (lock) {
lock.notifyAll();
}
}
/**
* Sets the value from successful execution and executes callback if available. Notifies any
* thread waiting for completion.
*
* @param value value of the evaluated task
*/
void setValue(T value) {
this.value = value;
this.state = COMPLETED;
this.callback.ifPresent(ac -> ac.onComplete(value, Optional.<Exception>empty()));
synchronized (lock) {
lock.notifyAll();
}
}
/**
* Sets the exception from failed execution and executes callback if available. Notifies
* any thread waiting for completion.
*
* @param exception exception of the failed task
*/
void setException(Exception exception) {
this.exception = exception;
this.state = FAILED;
this.callback.ifPresent(ac -> ac.onComplete(null, Optional.of(exception)));
synchronized (lock) {
lock.notifyAll();
}
}
/**
* Sets the exception from failed execution and executes callback if available. Notifies any
* thread waiting for completion.
*
* @param exception exception of the failed task
*/
void setException(Exception exception) {
this.exception = exception;
this.state = FAILED;
this.callback.ifPresent(ac -> ac.onComplete(null, Optional.of(exception)));
synchronized (lock) {
lock.notifyAll();
}
}
@Override
public boolean isCompleted() {
return (state > RUNNING);
}
@Override
public boolean isCompleted() {
return (state > RUNNING);
}
@Override
public T getValue() throws ExecutionException {
if (state == COMPLETED) {
return value;
} else if (state == FAILED) {
throw new ExecutionException(exception);
} else {
throw new IllegalStateException("Execution not completed yet");
}
}
@Override
public T getValue() throws ExecutionException {
if (state == COMPLETED) {
return value;
} else if (state == FAILED) {
throw new ExecutionException(exception);
} else {
throw new IllegalStateException("Execution not completed yet");
}
}
@Override
public void await() throws InterruptedException {
synchronized (lock) {
if (!isCompleted()) {
lock.wait();
}
}
}
}
@Override
public void await() throws InterruptedException {
synchronized (lock) {
if (!isCompleted()) {
lock.wait();
}
}
}
}
}

11
async-method-invocation/src/test/java/com/iluwatar/async/method/invocation/AppTest.java
View File

@ -9,10 +9,9 @@ import org.junit.Test;
*/
public class AppTest {
@Test
public void test() throws Exception {
String[] args = {};
App.main(args);
}
@Test
public void test() throws Exception {
String[] args = {};
App.main(args);
}
}

57
bridge/src/main/java/com/iluwatar/bridge/App.java
View File

@ -2,41 +2,38 @@ package com.iluwatar.bridge;
/**
*
* The Bridge pattern can also be thought of as two layers of abstraction. With Bridge,
* you can decouple an abstraction from its implementation so that the two can vary independently.
* The Bridge pattern can also be thought of as two layers of abstraction. With Bridge, you can
* decouple an abstraction from its implementation so that the two can vary independently.
* <p>
* In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation
* ({@link MagicWeaponImpl}) have their own class hierarchies. The interface of the
* implementations can be changed without affecting the clients.
* In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation (
* {@link MagicWeaponImpl}) have their own class hierarchies. The interface of the implementations
* can be changed without affecting the clients.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(
new Excalibur());
blindingMagicWeapon.wield();
blindingMagicWeapon.blind();
blindingMagicWeapon.swing();
blindingMagicWeapon.unwield();
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(new Excalibur());
blindingMagicWeapon.wield();
blindingMagicWeapon.blind();
blindingMagicWeapon.swing();
blindingMagicWeapon.unwield();
FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(
new Mjollnir());
flyingMagicWeapon.wield();
flyingMagicWeapon.fly();
flyingMagicWeapon.swing();
flyingMagicWeapon.unwield();
FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(new Mjollnir());
flyingMagicWeapon.wield();
flyingMagicWeapon.fly();
flyingMagicWeapon.swing();
flyingMagicWeapon.unwield();
SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(
new Stormbringer());
soulEatingMagicWeapon.wield();
soulEatingMagicWeapon.swing();
soulEatingMagicWeapon.eatSoul();
soulEatingMagicWeapon.unwield();
}
SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(new Stormbringer());
soulEatingMagicWeapon.wield();
soulEatingMagicWeapon.swing();
soulEatingMagicWeapon.eatSoul();
soulEatingMagicWeapon.unwield();
}
}

45
bridge/src/main/java/com/iluwatar/bridge/BlindingMagicWeapon.java
View File

@ -7,32 +7,31 @@ package com.iluwatar.bridge;
*/
public class BlindingMagicWeapon extends MagicWeapon {
public BlindingMagicWeapon(BlindingMagicWeaponImpl imp) {
super(imp);
}
public BlindingMagicWeapon(BlindingMagicWeaponImpl imp) {
super(imp);
}
@Override
public BlindingMagicWeaponImpl getImp() {
return (BlindingMagicWeaponImpl) imp;
}
@Override
public BlindingMagicWeaponImpl getImp() {
return (BlindingMagicWeaponImpl) imp;
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
public void blind() {
getImp().blindImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
public void blind() {
getImp().blindImp();
}
}

2
bridge/src/main/java/com/iluwatar/bridge/BlindingMagicWeaponImpl.java
View File

@ -7,6 +7,6 @@ package com.iluwatar.bridge;
*/
public abstract class BlindingMagicWeaponImpl extends MagicWeaponImpl {
public abstract void blindImp();
public abstract void blindImp();
}

34
bridge/src/main/java/com/iluwatar/bridge/Excalibur.java
View File

@ -7,25 +7,23 @@ package com.iluwatar.bridge;
*/
public class Excalibur extends BlindingMagicWeaponImpl {
@Override
public void wieldImp() {
System.out.println("wielding Excalibur");
}
@Override
public void wieldImp() {
System.out.println("wielding Excalibur");
}
@Override
public void swingImp() {
System.out.println("swinging Excalibur");
}
@Override
public void swingImp() {
System.out.println("swinging Excalibur");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Excalibur");
}
@Override
public void blindImp() {
System.out
.println("bright light streams from Excalibur blinding the enemy");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Excalibur");
}
@Override
public void blindImp() {
System.out.println("bright light streams from Excalibur blinding the enemy");
}
}

42
bridge/src/main/java/com/iluwatar/bridge/FlyingMagicWeapon.java
View File

@ -7,31 +7,31 @@ package com.iluwatar.bridge;
*/
public class FlyingMagicWeapon extends MagicWeapon {
public FlyingMagicWeapon(FlyingMagicWeaponImpl imp) {
super(imp);
}
public FlyingMagicWeapon(FlyingMagicWeaponImpl imp) {
super(imp);
}
public FlyingMagicWeaponImpl getImp() {
return (FlyingMagicWeaponImpl) imp;
}
public FlyingMagicWeaponImpl getImp() {
return (FlyingMagicWeaponImpl) imp;
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
public void fly() {
getImp().flyImp();
}
public void fly() {
getImp().flyImp();
}
}

2
bridge/src/main/java/com/iluwatar/bridge/FlyingMagicWeaponImpl.java
View File

@ -7,6 +7,6 @@ package com.iluwatar.bridge;
*/
public abstract class FlyingMagicWeaponImpl extends MagicWeaponImpl {
public abstract void flyImp();
public abstract void flyImp();
}

21
bridge/src/main/java/com/iluwatar/bridge/MagicWeapon.java
View File

@ -7,20 +7,19 @@ package com.iluwatar.bridge;
*/
public abstract class MagicWeapon {
protected MagicWeaponImpl imp;
protected MagicWeaponImpl imp;
public MagicWeapon(MagicWeaponImpl imp) {
this.imp = imp;
}
public MagicWeapon(MagicWeaponImpl imp) {
this.imp = imp;
}
public abstract void wield();
public abstract void wield();
public abstract void swing();
public abstract void swing();
public abstract void unwield();
public MagicWeaponImpl getImp() {
return imp;
}
public abstract void unwield();
public MagicWeaponImpl getImp() {
return imp;
}
}

6
bridge/src/main/java/com/iluwatar/bridge/MagicWeaponImpl.java
View File

@ -7,10 +7,10 @@ package com.iluwatar.bridge;
*/
public abstract class MagicWeaponImpl {
public abstract void wieldImp();
public abstract void wieldImp();
public abstract void swingImp();
public abstract void swingImp();
public abstract void unwieldImp();
public abstract void unwieldImp();
}

34
bridge/src/main/java/com/iluwatar/bridge/Mjollnir.java
View File

@ -7,25 +7,23 @@ package com.iluwatar.bridge;
*/
public class Mjollnir extends FlyingMagicWeaponImpl {
@Override
public void wieldImp() {
System.out.println("wielding Mjollnir");
}
@Override
public void wieldImp() {
System.out.println("wielding Mjollnir");
}
@Override
public void swingImp() {
System.out.println("swinging Mjollnir");
}
@Override
public void swingImp() {
System.out.println("swinging Mjollnir");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Mjollnir");
}
@Override
public void flyImp() {
System.out
.println("Mjollnir hits the enemy in the air and returns back to the owner's hand");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Mjollnir");
}
@Override
public void flyImp() {
System.out.println("Mjollnir hits the enemy in the air and returns back to the owner's hand");
}
}

44
bridge/src/main/java/com/iluwatar/bridge/SoulEatingMagicWeapon.java
View File

@ -7,32 +7,32 @@ package com.iluwatar.bridge;
*/
public class SoulEatingMagicWeapon extends MagicWeapon {
public SoulEatingMagicWeapon(SoulEatingMagicWeaponImpl imp) {
super(imp);
}
public SoulEatingMagicWeapon(SoulEatingMagicWeaponImpl imp) {
super(imp);
}
@Override
public SoulEatingMagicWeaponImpl getImp() {
return (SoulEatingMagicWeaponImpl) imp;
}
@Override
public SoulEatingMagicWeaponImpl getImp() {
return (SoulEatingMagicWeaponImpl) imp;
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void wield() {
getImp().wieldImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void swing() {
getImp().swingImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
@Override
public void unwield() {
getImp().unwieldImp();
}
public void eatSoul() {
getImp().eatSoulImp();
}
public void eatSoul() {
getImp().eatSoulImp();
}
}

2
bridge/src/main/java/com/iluwatar/bridge/SoulEatingMagicWeaponImpl.java
View File

@ -7,6 +7,6 @@ package com.iluwatar.bridge;
*/
public abstract class SoulEatingMagicWeaponImpl extends MagicWeaponImpl {
public abstract void eatSoulImp();
public abstract void eatSoulImp();
}

33
bridge/src/main/java/com/iluwatar/bridge/Stormbringer.java
View File

@ -7,24 +7,23 @@ package com.iluwatar.bridge;
*/
public class Stormbringer extends SoulEatingMagicWeaponImpl {
@Override
public void wieldImp() {
System.out.println("wielding Stormbringer");
}
@Override
public void wieldImp() {
System.out.println("wielding Stormbringer");
}
@Override
public void swingImp() {
System.out.println("swinging Stormbringer");
}
@Override
public void swingImp() {
System.out.println("swinging Stormbringer");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Stormbringer");
}
@Override
public void eatSoulImp() {
System.out.println("Stormbringer devours the enemy's soul");
}
@Override
public void unwieldImp() {
System.out.println("unwielding Stormbringer");
}
@Override
public void eatSoulImp() {
System.out.println("Stormbringer devours the enemy's soul");
}
}

10
bridge/src/test/java/com/iluwatar/bridge/AppTest.java
View File

@ -11,9 +11,9 @@ import com.iluwatar.bridge.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

76
builder/src/main/java/com/iluwatar/builder/App.java
View File

@ -1,55 +1,55 @@
package com.iluwatar.builder;
import com.iluwatar. builder.Hero.HeroBuilder;
import com.iluwatar.builder.Hero.HeroBuilder;
/**
*
* The intention of the Builder pattern is to find a solution to the telescoping
* constructor anti-pattern. The telescoping constructor anti-pattern occurs when the
* increase of object constructor parameter combination leads to an exponential list
* of constructors. Instead of using numerous constructors, the builder pattern uses
* another object, a builder, that receives each initialization parameter step by step
* and then returns the resulting constructed object at once.
* The intention of the Builder pattern is to find a solution to the telescoping constructor
* anti-pattern. The telescoping constructor anti-pattern occurs when the increase of object
* constructor parameter combination leads to an exponential list of constructors. Instead of using
* numerous constructors, the builder pattern uses another object, a builder, that receives each
* initialization parameter step by step and then returns the resulting constructed object at once.
* <p>
* The Builder pattern has another benefit. It can be used for objects that contain
* flat data (html code, SQL query, X.509 certificate...), that is to say, data that
* can't be easily edited. This type of data cannot be edited step by step and must
* be edited at once. The best way to construct such an object is to use a builder
* class.
* The Builder pattern has another benefit. It can be used for objects that contain flat data (html
* code, SQL query, X.509 certificate...), that is to say, data that can't be easily edited. This
* type of data cannot be edited step by step and must be edited at once. The best way to construct
* such an object is to use a builder class.
* <p>
* In this example we have the Builder pattern variation as described by Joshua Bloch in
* Effective Java 2nd Edition.
* In this example we have the Builder pattern variation as described by Joshua Bloch in Effective
* Java 2nd Edition.
* <p>
* We want to build {@link Hero} objects, but its construction is complex because of the
* many parameters needed. To aid the user we introduce {@link HeroBuilder} class.
* {@link HeroBuilder} takes the minimum parameters to build {@link Hero} object in its
* constructor. After that additional configuration for the {@link Hero} object can be
* done using the fluent {@link HeroBuilder} interface. When configuration is ready the
* build method is called to receive the final {@link Hero} object.
* We want to build {@link Hero} objects, but its construction is complex because of the many
* parameters needed. To aid the user we introduce {@link HeroBuilder} class. {@link HeroBuilder}
* takes the minimum parameters to build {@link Hero} object in its constructor. After that
* additional configuration for the {@link Hero} object can be done using the fluent
* {@link HeroBuilder} interface. When configuration is ready the build method is called to receive
* the final {@link Hero} object.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
Hero mage = new HeroBuilder(Profession.MAGE, "Riobard")
.withHairColor(HairColor.BLACK).withWeapon(Weapon.DAGGER)
.build();
System.out.println(mage);
Hero mage =
new HeroBuilder(Profession.MAGE, "Riobard").withHairColor(HairColor.BLACK)
.withWeapon(Weapon.DAGGER).build();
System.out.println(mage);
Hero warrior = new HeroBuilder(Profession.WARRIOR, "Amberjill")
.withHairColor(HairColor.BLOND)
.withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL)
.withWeapon(Weapon.SWORD).build();
System.out.println(warrior);
Hero warrior =
new HeroBuilder(Profession.WARRIOR, "Amberjill").withHairColor(HairColor.BLOND)
.withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL).withWeapon(Weapon.SWORD)
.build();
System.out.println(warrior);
Hero thief = new HeroBuilder(Profession.THIEF, "Desmond")
.withHairType(HairType.BALD).withWeapon(Weapon.BOW).build();
System.out.println(thief);
Hero thief =
new HeroBuilder(Profession.THIEF, "Desmond").withHairType(HairType.BALD)
.withWeapon(Weapon.BOW).build();
System.out.println(thief);
}
}
}

18
builder/src/main/java/com/iluwatar/builder/Armor.java
View File

@ -7,16 +7,16 @@ package com.iluwatar.builder;
*/
public enum Armor {
CLOTHES("clothes"), LEATHER("leather"), CHAIN_MAIL("chain mail"), PLATE_MAIL("plate mail");
CLOTHES("clothes"), LEATHER("leather"), CHAIN_MAIL("chain mail"), PLATE_MAIL("plate mail");
private String title;
private String title;
Armor(String title) {
this.title = title;
}
Armor(String title) {
this.title = title;
}
@Override
public String toString() {
return title;
}
@Override
public String toString() {
return title;
}
}

10
builder/src/main/java/com/iluwatar/builder/HairColor.java
View File

@ -7,11 +7,11 @@ package com.iluwatar.builder;
*/
public enum HairColor {
WHITE, BLOND, RED, BROWN, BLACK;
WHITE, BLOND, RED, BROWN, BLACK;
@Override
public String toString() {
return name().toLowerCase();
}
@Override
public String toString() {
return name().toLowerCase();
}
}

19
builder/src/main/java/com/iluwatar/builder/HairType.java
View File

@ -7,16 +7,17 @@ package com.iluwatar.builder;
*/
public enum HairType {
BALD("bald"), SHORT("short"), CURLY("curly"), LONG_STRAIGHT("long straight"), LONG_CURLY("long curly");
BALD("bald"), SHORT("short"), CURLY("curly"), LONG_STRAIGHT("long straight"), LONG_CURLY(
"long curly");
private String title;
private String title;
HairType(String title) {
this.title = title;
}
HairType(String title) {
this.title = title;
}
@Override
public String toString() {
return title;
}
@Override
public String toString() {
return title;
}
}

203
builder/src/main/java/com/iluwatar/builder/Hero.java
View File

@ -7,123 +7,122 @@ package com.iluwatar.builder;
*/
public class Hero {
private final Profession profession;
private final String name;
private final HairType hairType;
private final HairColor hairColor;
private final Armor armor;
private final Weapon weapon;
private final Profession profession;
private final String name;
private final HairType hairType;
private final HairColor hairColor;
private final Armor armor;
private final Weapon weapon;
public Profession getProfession() {
return profession;
}
public Profession getProfession() {
return profession;
}
public String getName() {
return name;
}
public String getName() {
return name;
}
public HairType getHairType() {
return hairType;
}
public HairType getHairType() {
return hairType;
}
public HairColor getHairColor() {
return hairColor;
}
public HairColor getHairColor() {
return hairColor;
}
public Armor getArmor() {
return armor;
}
public Armor getArmor() {
return armor;
}
public Weapon getWeapon() {
return weapon;
}
public Weapon getWeapon() {
return weapon;
}
@Override
public String toString() {
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("This is a ");
sb.append(profession);
sb.append(" named ");
sb.append(name);
if (hairColor != null || hairType != null) {
sb.append(" with ");
if (hairColor != null) {
sb.append(hairColor);
sb.append(" ");
}
if (hairType != null) {
sb.append(hairType);
sb.append(" ");
}
sb.append(hairType != HairType.BALD ? "hair" : "head");
}
if (armor != null) {
sb.append(" wearing ");
sb.append(armor);
}
if (weapon != null) {
sb.append(" and wielding a ");
sb.append(weapon);
}
sb.append(".");
return sb.toString();
}
StringBuilder sb = new StringBuilder();
sb.append("This is a ");
sb.append(profession);
sb.append(" named ");
sb.append(name);
if (hairColor != null || hairType != null) {
sb.append(" with ");
if (hairColor != null) {
sb.append(hairColor);
sb.append(" ");
}
if (hairType != null) {
sb.append(hairType);
sb.append(" ");
}
sb.append(hairType != HairType.BALD ? "hair" : "head");
}
if (armor != null) {
sb.append(" wearing ");
sb.append(armor);
}
if (weapon != null) {
sb.append(" and wielding a ");
sb.append(weapon);
}
sb.append(".");
return sb.toString();
}
private Hero(HeroBuilder builder) {
this.profession = builder.profession;
this.name = builder.name;
this.hairColor = builder.hairColor;
this.hairType = builder.hairType;
this.weapon = builder.weapon;
this.armor = builder.armor;
}
private Hero(HeroBuilder builder) {
this.profession = builder.profession;
this.name = builder.name;
this.hairColor = builder.hairColor;
this.hairType = builder.hairType;
this.weapon = builder.weapon;
this.armor = builder.armor;
}
/**
*
* The builder class.
*
*/
public static class HeroBuilder {
/**
*
* The builder class.
*
*/
public static class HeroBuilder {
private final Profession profession;
private final String name;
private HairType hairType;
private HairColor hairColor;
private Armor armor;
private Weapon weapon;
private final Profession profession;
private final String name;
private HairType hairType;
private HairColor hairColor;
private Armor armor;
private Weapon weapon;
public HeroBuilder(Profession profession, String name) {
if (profession == null || name == null) {
throw new IllegalArgumentException(
"profession and name can not be null");
}
this.profession = profession;
this.name = name;
}
public HeroBuilder(Profession profession, String name) {
if (profession == null || name == null) {
throw new IllegalArgumentException("profession and name can not be null");
}
this.profession = profession;
this.name = name;
}
public HeroBuilder withHairType(HairType hairType) {
this.hairType = hairType;
return this;
}
public HeroBuilder withHairType(HairType hairType) {
this.hairType = hairType;
return this;
}
public HeroBuilder withHairColor(HairColor hairColor) {
this.hairColor = hairColor;
return this;
}
public HeroBuilder withHairColor(HairColor hairColor) {
this.hairColor = hairColor;
return this;
}
public HeroBuilder withArmor(Armor armor) {
this.armor = armor;
return this;
}
public HeroBuilder withArmor(Armor armor) {
this.armor = armor;
return this;
}
public HeroBuilder withWeapon(Weapon weapon) {
this.weapon = weapon;
return this;
}
public HeroBuilder withWeapon(Weapon weapon) {
this.weapon = weapon;
return this;
}
public Hero build() {
return new Hero(this);
}
}
public Hero build() {
return new Hero(this);
}
}
}

11
builder/src/main/java/com/iluwatar/builder/Profession.java
View File

@ -7,11 +7,10 @@ package com.iluwatar.builder;
*/
public enum Profession {
WARRIOR, THIEF, MAGE, PRIEST;
@Override
public String toString() {
return name().toLowerCase();
}
WARRIOR, THIEF, MAGE, PRIEST;
@Override
public String toString() {
return name().toLowerCase();
}
}

11
builder/src/main/java/com/iluwatar/builder/Weapon.java
View File

@ -7,11 +7,10 @@ package com.iluwatar.builder;
*/
public enum Weapon {
DAGGER, SWORD, AXE, WARHAMMER, BOW;
@Override
public String toString() {
return name().toLowerCase();
}
DAGGER, SWORD, AXE, WARHAMMER, BOW;
@Override
public String toString() {
return name().toLowerCase();
}
}

12
builder/src/test/java/com/iluwatar/builder/AppTest.java
View File

@ -2,7 +2,7 @@ package com.iluwatar.builder;
import org.junit.Test;
import com.iluwatar. builder.App;
import com.iluwatar.builder.App;
/**
*
@ -11,9 +11,9 @@ import com.iluwatar. builder.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

48
business-delegate/src/main/java/com/iluwatar/business/delegate/App.java
View File

@ -2,34 +2,36 @@ package com.iluwatar.business.delegate;
/**
*
* The Business Delegate pattern adds an abstraction layer between the presentation and business tiers.
* By using the pattern we gain loose coupling between the tiers. The Business Delegate encapsulates
* knowledge about how to locate, connect to, and interact with the business objects that make up
* the application.
* The Business Delegate pattern adds an abstraction layer between the presentation and business
* tiers. By using the pattern we gain loose coupling between the tiers. The Business Delegate
* encapsulates knowledge about how to locate, connect to, and interact with the business objects
* that make up the application.
* <p>
* Some of the services the Business Delegate uses are instantiated directly, and some can be retrieved
* through service lookups. The Business Delegate itself may contain business logic too potentially tying
* together multiple service calls, exception handling, retrying etc.
* Some of the services the Business Delegate uses are instantiated directly, and some can be
* retrieved through service lookups. The Business Delegate itself may contain business logic too
* potentially tying together multiple service calls, exception handling, retrying etc.
* <p>
* In this example the client ({@link Client}) utilizes a business delegate ({@link BusinessDelegate}) to execute a task.
* The Business Delegate then selects the appropriate service and makes the service call.
* In this example the client ({@link Client}) utilizes a business delegate (
* {@link BusinessDelegate}) to execute a task. The Business Delegate then selects the appropriate
* service and makes the service call.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
BusinessDelegate businessDelegate = new BusinessDelegate();
businessDelegate.setServiceType(ServiceType.EJB);
Client client = new Client(businessDelegate);
client.doTask();
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
businessDelegate.setServiceType(ServiceType.JMS);
client.doTask();
}
BusinessDelegate businessDelegate = new BusinessDelegate();
businessDelegate.setServiceType(ServiceType.EJB);
Client client = new Client(businessDelegate);
client.doTask();
businessDelegate.setServiceType(ServiceType.JMS);
client.doTask();
}
}

22
business-delegate/src/main/java/com/iluwatar/business/delegate/BusinessDelegate.java
View File

@ -6,17 +6,17 @@ package com.iluwatar.business.delegate;
*
*/
public class BusinessDelegate {
private BusinessLookup lookupService = new BusinessLookup();
private BusinessService businessService;
private ServiceType serviceType;
public void setServiceType(ServiceType serviceType) {
this.serviceType = serviceType;
}
private BusinessLookup lookupService = new BusinessLookup();
private BusinessService businessService;
private ServiceType serviceType;
public void doTask() {
businessService = lookupService.getBusinessService(serviceType);
businessService.doProcessing();
}
public void setServiceType(ServiceType serviceType) {
this.serviceType = serviceType;
}
public void doTask() {
businessService = lookupService.getBusinessService(serviceType);
businessService.doProcessing();
}
}

14
business-delegate/src/main/java/com/iluwatar/business/delegate/BusinessLookup.java
View File

@ -7,11 +7,11 @@ package com.iluwatar.business.delegate;
*/
public class BusinessLookup {
public BusinessService getBusinessService(ServiceType serviceType) {
if (serviceType.equals(ServiceType.EJB)) {
return new EjbService();
} else {
return new JmsService();
}
}
public BusinessService getBusinessService(ServiceType serviceType) {
if (serviceType.equals(ServiceType.EJB)) {
return new EjbService();
} else {
return new JmsService();
}
}
}

2
business-delegate/src/main/java/com/iluwatar/business/delegate/BusinessService.java
View File

@ -7,5 +7,5 @@ package com.iluwatar.business.delegate;
*/
public interface BusinessService {
void doProcessing();
void doProcessing();
}

14
business-delegate/src/main/java/com/iluwatar/business/delegate/Client.java
View File

@ -7,13 +7,13 @@ package com.iluwatar.business.delegate;
*/
public class Client {
private BusinessDelegate businessDelegate;
private BusinessDelegate businessDelegate;
public Client(BusinessDelegate businessDelegate) {
this.businessDelegate = businessDelegate;
}
public Client(BusinessDelegate businessDelegate) {
this.businessDelegate = businessDelegate;
}
public void doTask() {
businessDelegate.doTask();
}
public void doTask() {
businessDelegate.doTask();
}
}

8
business-delegate/src/main/java/com/iluwatar/business/delegate/EjbService.java
View File

@ -7,8 +7,8 @@ package com.iluwatar.business.delegate;
*/
public class EjbService implements BusinessService {
@Override
public void doProcessing() {
System.out.println("EjbService is now processing");
}
@Override
public void doProcessing() {
System.out.println("EjbService is now processing");
}
}

8
business-delegate/src/main/java/com/iluwatar/business/delegate/JmsService.java
View File

@ -7,8 +7,8 @@ package com.iluwatar.business.delegate;
*/
public class JmsService implements BusinessService {
@Override
public void doProcessing() {
System.out.println("JmsService is now processing");
}
@Override
public void doProcessing() {
System.out.println("JmsService is now processing");
}
}

4
business-delegate/src/main/java/com/iluwatar/business/delegate/ServiceType.java
View File

@ -6,6 +6,6 @@ package com.iluwatar.business.delegate;
*
*/
public enum ServiceType {
EJB, JMS;
EJB, JMS;
}

12
business-delegate/src/test/java/com/iluwatar/business/delegate/AppTest.java
View File

@ -10,10 +10,10 @@ import com.iluwatar.business.delegate.App;
*
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

25
callback/src/main/java/com/iluwatar/callback/App.java
View File

@ -2,20 +2,21 @@ package com.iluwatar.callback;
/**
*
* Callback pattern is more native for functional languages where functions are treated as first-class citizens.
* Prior to Java 8 callbacks can be simulated using simple (alike command) interfaces.
* Callback pattern is more native for functional languages where functions are treated as
* first-class citizens. Prior to Java 8 callbacks can be simulated using simple (alike command)
* interfaces.
*
*/
public class App {
public static void main(String[] args) {
Task task = new SimpleTask();
Callback callback = new Callback() {
@Override
public void call() {
System.out.println("I'm done now.");
}
};
task.executeWith(callback);
}
public static void main(String[] args) {
Task task = new SimpleTask();
Callback callback = new Callback() {
@Override
public void call() {
System.out.println("I'm done now.");
}
};
task.executeWith(callback);
}
}

2
callback/src/main/java/com/iluwatar/callback/Callback.java
View File

@ -7,5 +7,5 @@ package com.iluwatar.callback;
*/
public interface Callback {
public void call();
public void call();
}

9
callback/src/main/java/com/iluwatar/callback/SimpleTask.java
View File

@ -7,9 +7,8 @@ package com.iluwatar.callback;
*/
public class SimpleTask extends Task {
@Override
public void execute() {
System.out.println("Perform some important activity and after call the callback method.");
}
@Override
public void execute() {
System.out.println("Perform some important activity and after call the callback method.");
}
}

14
callback/src/main/java/com/iluwatar/callback/Task.java
View File

@ -7,12 +7,12 @@ package com.iluwatar.callback;
*/
public abstract class Task {
public final void executeWith(Callback callback) {
execute();
if (callback != null) {
callback.call();
}
}
public final void executeWith(Callback callback) {
execute();
if (callback != null) {
callback.call();
}
}
public abstract void execute();
public abstract void execute();
}

36
callback/src/test/java/com/iluwatar/callback/AppTest.java
View File

@ -5,35 +5,35 @@ import org.junit.Test;
import static org.junit.Assert.assertEquals;
/**
* Add a field as a counter. Every time the callback method is called increment this
* field. Unit test checks that the field is being incremented.
* Add a field as a counter. Every time the callback method is called increment this field. Unit
* test checks that the field is being incremented.
*
* Could be done with mock objects as well where the call method call is verified.
*/
public class AppTest {
private Integer callingCount = 0;
private Integer callingCount = 0;
@Test
public void test() {
Callback callback = new Callback() {
@Override
public void call() {
callingCount++;
}
};
@Test
public void test() {
Callback callback = new Callback() {
@Override
public void call() {
callingCount++;
}
};
Task task = new SimpleTask();
Task task = new SimpleTask();
assertEquals("Initial calling count of 0", new Integer(0), callingCount);
assertEquals("Initial calling count of 0", new Integer(0), callingCount);
task.executeWith(callback);
task.executeWith(callback);
assertEquals("Callback called once", new Integer(1), callingCount);
assertEquals("Callback called once", new Integer(1), callingCount);
task.executeWith(callback);
task.executeWith(callback);
assertEquals("Callback called twice", new Integer(2), callingCount);
assertEquals("Callback called twice", new Integer(2), callingCount);
}
}
}

39
chain/src/main/java/com/iluwatar/chain/App.java
View File

@ -2,31 +2,30 @@ package com.iluwatar.chain;
/**
*
* The Chain of Responsibility pattern is a design pattern consisting of command
* objects and a series of processing objects. Each processing object contains
* logic that defines the types of command objects that it can handle; the rest are
* passed to the next processing object in the chain. A mechanism also exists for
* adding new processing objects to the end of this chain.
* The Chain of Responsibility pattern is a design pattern consisting of command objects and a
* series of processing objects. Each processing object contains logic that defines the types of
* command objects that it can handle; the rest are passed to the next processing object in the
* chain. A mechanism also exists for adding new processing objects to the end of this chain.
* <p>
* In this example we organize the request handlers ({@link RequestHandler}) into a
* chain where each handler has a chance to act on the request on its turn. Here
* the king ({@link OrcKing}) makes requests and the military orcs ({@link OrcCommander},
* {@link OrcOfficer}, {@link OrcSoldier}) form the handler chain.
* In this example we organize the request handlers ({@link RequestHandler}) into a chain where each
* handler has a chance to act on the request on its turn. Here the king ({@link OrcKing}) makes
* requests and the military orcs ({@link OrcCommander}, {@link OrcOfficer}, {@link OrcSoldier})
* form the handler chain.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
OrcKing king = new OrcKing();
king.makeRequest(new Request(RequestType.DEFEND_CASTLE, "defend castle"));
king.makeRequest(new Request(RequestType.TORTURE_PRISONER,
"torture prisoner"));
king.makeRequest(new Request(RequestType.COLLECT_TAX, "collect tax"));
OrcKing king = new OrcKing();
king.makeRequest(new Request(RequestType.DEFEND_CASTLE, "defend castle"));
king.makeRequest(new Request(RequestType.TORTURE_PRISONER, "torture prisoner"));
king.makeRequest(new Request(RequestType.COLLECT_TAX, "collect tax"));
}
}
}

30
chain/src/main/java/com/iluwatar/chain/OrcCommander.java
View File

@ -7,21 +7,21 @@ package com.iluwatar.chain;
*/
public class OrcCommander extends RequestHandler {
public OrcCommander(RequestHandler handler) {
super(handler);
}
public OrcCommander(RequestHandler handler) {
super(handler);
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.DEFEND_CASTLE)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.DEFEND_CASTLE)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public String toString() {
return "Orc commander";
}
@Override
public String toString() {
return "Orc commander";
}
}

20
chain/src/main/java/com/iluwatar/chain/OrcKing.java
View File

@ -7,18 +7,18 @@ package com.iluwatar.chain;
*/
public class OrcKing {
RequestHandler chain;
RequestHandler chain;
public OrcKing() {
buildChain();
}
public OrcKing() {
buildChain();
}
private void buildChain() {
chain = new OrcCommander(new OrcOfficer(new OrcSoldier(null)));
}
private void buildChain() {
chain = new OrcCommander(new OrcOfficer(new OrcSoldier(null)));
}
public void makeRequest(Request req) {
chain.handleRequest(req);
}
public void makeRequest(Request req) {
chain.handleRequest(req);
}
}

30
chain/src/main/java/com/iluwatar/chain/OrcOfficer.java
View File

@ -7,22 +7,22 @@ package com.iluwatar.chain;
*/
public class OrcOfficer extends RequestHandler {
public OrcOfficer(RequestHandler handler) {
super(handler);
}
public OrcOfficer(RequestHandler handler) {
super(handler);
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.TORTURE_PRISONER)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.TORTURE_PRISONER)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public String toString() {
return "Orc officer";
}
@Override
public String toString() {
return "Orc officer";
}
}

30
chain/src/main/java/com/iluwatar/chain/OrcSoldier.java
View File

@ -7,21 +7,21 @@ package com.iluwatar.chain;
*/
public class OrcSoldier extends RequestHandler {
public OrcSoldier(RequestHandler handler) {
super(handler);
}
public OrcSoldier(RequestHandler handler) {
super(handler);
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.COLLECT_TAX)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public void handleRequest(Request req) {
if (req.getRequestType().equals(RequestType.COLLECT_TAX)) {
printHandling(req);
} else {
super.handleRequest(req);
}
}
@Override
public String toString() {
return "Orc soldier";
}
@Override
public String toString() {
return "Orc soldier";
}
}

44
chain/src/main/java/com/iluwatar/chain/Request.java
View File

@ -7,32 +7,32 @@ package com.iluwatar.chain;
*/
public class Request {
private String requestDescription;
private RequestType requestType;
private String requestDescription;
private RequestType requestType;
public Request(RequestType requestType, String requestDescription) {
this.setRequestType(requestType);
this.setRequestDescription(requestDescription);
}
public Request(RequestType requestType, String requestDescription) {
this.setRequestType(requestType);
this.setRequestDescription(requestDescription);
}
public String getRequestDescription() {
return requestDescription;
}
public String getRequestDescription() {
return requestDescription;
}
public void setRequestDescription(String requestDescription) {
this.requestDescription = requestDescription;
}
public void setRequestDescription(String requestDescription) {
this.requestDescription = requestDescription;
}
public RequestType getRequestType() {
return requestType;
}
public RequestType getRequestType() {
return requestType;
}
public void setRequestType(RequestType requestType) {
this.requestType = requestType;
}
public void setRequestType(RequestType requestType) {
this.requestType = requestType;
}
@Override
public String toString() {
return getRequestDescription();
}
@Override
public String toString() {
return getRequestDescription();
}
}

28
chain/src/main/java/com/iluwatar/chain/RequestHandler.java
View File

@ -7,22 +7,22 @@ package com.iluwatar.chain;
*/
public abstract class RequestHandler {
private RequestHandler next;
private RequestHandler next;
public RequestHandler(RequestHandler next) {
this.next = next;
}
public RequestHandler(RequestHandler next) {
this.next = next;
}
public void handleRequest(Request req) {
if (next != null) {
next.handleRequest(req);
}
}
public void handleRequest(Request req) {
if (next != null) {
next.handleRequest(req);
}
}
protected void printHandling(Request req) {
System.out.println(this + " handling request \"" + req + "\"");
}
protected void printHandling(Request req) {
System.out.println(this + " handling request \"" + req + "\"");
}
@Override
public abstract String toString();
@Override
public abstract String toString();
}

2
chain/src/main/java/com/iluwatar/chain/RequestType.java
View File

@ -7,6 +7,6 @@ package com.iluwatar.chain;
*/
public enum RequestType {
DEFEND_CASTLE, TORTURE_PRISONER, COLLECT_TAX
DEFEND_CASTLE, TORTURE_PRISONER, COLLECT_TAX
}

10
chain/src/test/java/com/iluwatar/chain/AppTest.java
View File

@ -11,9 +11,9 @@ import com.iluwatar.chain.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

70
command/src/main/java/com/iluwatar/command/App.java
View File

@ -2,52 +2,54 @@ package com.iluwatar.command;
/**
*
* The Command pattern is a behavioral design pattern in which an object is used to encapsulate all information
* needed to perform an action or trigger an event at a later time. This information includes the method name,
* the object that owns the method and values for the method parameters.
* The Command pattern is a behavioral design pattern in which an object is used to encapsulate all
* information needed to perform an action or trigger an event at a later time. This information
* includes the method name, the object that owns the method and values for the method parameters.
* <p>
* Four terms always associated with the command pattern are command, receiver, invoker and client. A command
* object (spell) knows about the receiver (target) and invokes a method of the receiver. Values for parameters of
* the receiver method are stored in the command. The receiver then does the work. An invoker object (wizard)
* knows how to execute a command, and optionally does bookkeeping about the command execution. The invoker
* does not know anything about a concrete command, it knows only about command interface. Both an invoker object
* and several command objects are held by a client object (app). The client decides which commands to execute at
* which points. To execute a command, it passes the command object to the invoker object.
* Four terms always associated with the command pattern are command, receiver, invoker and client.
* A command object (spell) knows about the receiver (target) and invokes a method of the receiver.
* Values for parameters of the receiver method are stored in the command. The receiver then does
* the work. An invoker object (wizard) knows how to execute a command, and optionally does
* bookkeeping about the command execution. The invoker does not know anything about a concrete
* command, it knows only about command interface. Both an invoker object and several command
* objects are held by a client object (app). The client decides which commands to execute at which
* points. To execute a command, it passes the command object to the invoker object.
* <p>
* In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of the previous
* spells cast, so it is easy to undo them. In addition, the wizard keeps track of the spells undone, so they
* can be redone.
* In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of
* the previous spells cast, so it is easy to undo them. In addition, the wizard keeps track of the
* spells undone, so they can be redone.
*
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
Wizard wizard = new Wizard();
Goblin goblin = new Goblin();
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
Wizard wizard = new Wizard();
Goblin goblin = new Goblin();
goblin.printStatus();
goblin.printStatus();
wizard.castSpell(new ShrinkSpell(), goblin);
goblin.printStatus();
wizard.castSpell(new ShrinkSpell(), goblin);
goblin.printStatus();
wizard.castSpell(new InvisibilitySpell(), goblin);
goblin.printStatus();
wizard.castSpell(new InvisibilitySpell(), goblin);
goblin.printStatus();
wizard.undoLastSpell();
goblin.printStatus();
wizard.undoLastSpell();
goblin.printStatus();
wizard.undoLastSpell();
goblin.printStatus();
wizard.undoLastSpell();
goblin.printStatus();
wizard.redoLastSpell();
goblin.printStatus();
wizard.redoLastSpell();
goblin.printStatus();
wizard.redoLastSpell();
goblin.printStatus();
}
wizard.redoLastSpell();
goblin.printStatus();
}
}

10
command/src/main/java/com/iluwatar/command/Command.java
View File

@ -7,13 +7,13 @@ package com.iluwatar.command;
*/
public abstract class Command {
public abstract void execute(Target target);
public abstract void execute(Target target);
public abstract void undo();
public abstract void undo();
public abstract void redo();
public abstract void redo();
@Override
public abstract String toString();
@Override
public abstract String toString();
}

16
command/src/main/java/com/iluwatar/command/Goblin.java
View File

@ -7,14 +7,14 @@ package com.iluwatar.command;
*/
public class Goblin extends Target {
public Goblin() {
setSize(Size.NORMAL);
setVisibility(Visibility.VISIBLE);
}
public Goblin() {
setSize(Size.NORMAL);
setVisibility(Visibility.VISIBLE);
}
@Override
public String toString() {
return "Goblin";
}
@Override
public String toString() {
return "Goblin";
}
}

44
command/src/main/java/com/iluwatar/command/InvisibilitySpell.java
View File

@ -7,30 +7,30 @@ package com.iluwatar.command;
*/
public class InvisibilitySpell extends Command {
private Target target;
private Target target;
@Override
public void execute(Target target) {
target.setVisibility(Visibility.INVISIBLE);
this.target = target;
}
@Override
public void execute(Target target) {
target.setVisibility(Visibility.INVISIBLE);
this.target = target;
}
@Override
public void undo() {
if (target != null) {
target.setVisibility(Visibility.VISIBLE);
}
}
@Override
public void undo() {
if (target != null) {
target.setVisibility(Visibility.VISIBLE);
}
}
@Override
public void redo() {
if (target != null) {
target.setVisibility(Visibility.INVISIBLE);
}
}
@Override
public void redo() {
if (target != null) {
target.setVisibility(Visibility.INVISIBLE);
}
}
@Override
public String toString() {
return "Invisibility spell";
}
@Override
public String toString() {
return "Invisibility spell";
}
}

48
command/src/main/java/com/iluwatar/command/ShrinkSpell.java
View File

@ -7,32 +7,32 @@ package com.iluwatar.command;
*/
public class ShrinkSpell extends Command {
private Size oldSize;
private Target target;
private Size oldSize;
private Target target;
@Override
public void execute(Target target) {
oldSize = target.getSize();
target.setSize(Size.SMALL);
this.target = target;
}
@Override
public void execute(Target target) {
oldSize = target.getSize();
target.setSize(Size.SMALL);
this.target = target;
}
@Override
public void undo() {
if (oldSize != null && target != null) {
Size temp = target.getSize();
target.setSize(oldSize);
oldSize = temp;
}
}
@Override
public void undo() {
if (oldSize != null && target != null) {
Size temp = target.getSize();
target.setSize(oldSize);
oldSize = temp;
}
}
@Override
public void redo() {
undo();
}
@Override
public void redo() {
undo();
}
@Override
public String toString() {
return "Shrink spell";
}
@Override
public String toString() {
return "Shrink spell";
}
}

20
command/src/main/java/com/iluwatar/command/Size.java
View File

@ -7,16 +7,16 @@ package com.iluwatar.command;
*/
public enum Size {
SMALL("small"), NORMAL("normal"), LARGE("large"), UNDEFINED("");
private String title;
SMALL("small"), NORMAL("normal"), LARGE("large"), UNDEFINED("");
Size(String title) {
this.title = title;
}
private String title;
@Override
public String toString() {
return title;
}
Size(String title) {
this.title = title;
}
@Override
public String toString() {
return title;
}
}

42
command/src/main/java/com/iluwatar/command/Target.java
View File

@ -7,32 +7,32 @@ package com.iluwatar.command;
*/
public abstract class Target {
private Size size;
private Size size;
private Visibility visibility;
private Visibility visibility;
public Size getSize() {
return size;
}
public Size getSize() {
return size;
}
public void setSize(Size size) {
this.size = size;
}
public void setSize(Size size) {
this.size = size;
}
public Visibility getVisibility() {
return visibility;
}
public Visibility getVisibility() {
return visibility;
}
public void setVisibility(Visibility visibility) {
this.visibility = visibility;
}
public void setVisibility(Visibility visibility) {
this.visibility = visibility;
}
@Override
public abstract String toString();
@Override
public abstract String toString();
public void printStatus() {
System.out.println(String.format("%s, [size=%s] [visibility=%s]", this,
getSize(), getVisibility()));
System.out.println();
}
public void printStatus() {
System.out.println(String.format("%s, [size=%s] [visibility=%s]", this, getSize(),
getVisibility()));
System.out.println();
}
}

18
command/src/main/java/com/iluwatar/command/Visibility.java
View File

@ -7,16 +7,16 @@ package com.iluwatar.command;
*/
public enum Visibility {
VISIBLE("visible"), INVISIBLE("invisible"), UNDEFINED("");
VISIBLE("visible"), INVISIBLE("invisible"), UNDEFINED("");
private String title;
private String title;
Visibility(String title) {
this.title = title;
}
Visibility(String title) {
this.title = title;
}
@Override
public String toString() {
return title;
}
@Override
public String toString() {
return title;
}
}

57
command/src/main/java/com/iluwatar/command/Wizard.java
View File

@ -10,38 +10,37 @@ import java.util.LinkedList;
*/
public class Wizard {
private Deque<Command> undoStack = new LinkedList<>();
private Deque<Command> redoStack = new LinkedList<>();
private Deque<Command> undoStack = new LinkedList<>();
private Deque<Command> redoStack = new LinkedList<>();
public Wizard() {
}
public Wizard() {}
public void castSpell(Command command, Target target) {
System.out.println(this + " casts " + command + " at " + target);
command.execute(target);
undoStack.offerLast(command);
}
public void castSpell(Command command, Target target) {
System.out.println(this + " casts " + command + " at " + target);
command.execute(target);
undoStack.offerLast(command);
}
public void undoLastSpell() {
if (!undoStack.isEmpty()) {
Command previousSpell = undoStack.pollLast();
redoStack.offerLast(previousSpell);
System.out.println(this + " undoes " + previousSpell);
previousSpell.undo();
}
}
public void undoLastSpell() {
if (!undoStack.isEmpty()) {
Command previousSpell = undoStack.pollLast();
redoStack.offerLast(previousSpell);
System.out.println(this + " undoes " + previousSpell);
previousSpell.undo();
}
}
public void redoLastSpell() {
if (!redoStack.isEmpty()) {
Command previousSpell = redoStack.pollLast();
undoStack.offerLast(previousSpell);
System.out.println(this + " redoes " + previousSpell);
previousSpell.redo();
}
}
public void redoLastSpell() {
if (!redoStack.isEmpty()) {
Command previousSpell = redoStack.pollLast();
undoStack.offerLast(previousSpell);
System.out.println(this + " redoes " + previousSpell);
previousSpell.redo();
}
}
@Override
public String toString() {
return "Wizard";
}
@Override
public String toString() {
return "Wizard";
}
}

10
command/src/test/java/com/iluwatar/command/AppTest.java
View File

@ -11,9 +11,9 @@ import com.iluwatar.command.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

41
composite/src/main/java/com/iluwatar/composite/App.java
View File

@ -1,33 +1,34 @@
package com.iluwatar.composite;
/**
* The Composite pattern is a partitioning design pattern. The Composite pattern
* describes that a group of objects is to be treated in the same way as a single
* instance of an object. The intent of a composite is to "compose" objects into
* tree structures to represent part-whole hierarchies. Implementing the Composite
* pattern lets clients treat individual objects and compositions uniformly.
* The Composite pattern is a partitioning design pattern. The Composite pattern describes that a
* group of objects is to be treated in the same way as a single instance of an object. The intent
* of a composite is to "compose" objects into tree structures to represent part-whole hierarchies.
* Implementing the Composite pattern lets clients treat individual objects and compositions
* uniformly.
* <p>
* In this example we have sentences composed of words composed of letters. All of
* the objects can be treated through the same interface ({@link LetterComposite}).
* In this example we have sentences composed of words composed of letters. All of the objects can
* be treated through the same interface ({@link LetterComposite}).
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
System.out.println("Message from the orcs: ");
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
System.out.println("Message from the orcs: ");
LetterComposite orcMessage = new Messenger().messageFromOrcs();
orcMessage.print();
LetterComposite orcMessage = new Messenger().messageFromOrcs();
orcMessage.print();
System.out.println("\n");
System.out.println("\n");
System.out.println("Message from the elves: ");
System.out.println("Message from the elves: ");
LetterComposite elfMessage = new Messenger().messageFromElves();
elfMessage.print();
}
LetterComposite elfMessage = new Messenger().messageFromElves();
elfMessage.print();
}
}

25
composite/src/main/java/com/iluwatar/composite/Letter.java
View File

@ -7,20 +7,19 @@ package com.iluwatar.composite;
*/
public class Letter extends LetterComposite {
private char c;
private char c;
public Letter(char c) {
this.c = c;
}
public Letter(char c) {
this.c = c;
}
@Override
protected void printThisBefore() {
System.out.print(c);
}
@Override
protected void printThisAfter() {
// nop
}
@Override
protected void printThisBefore() {
System.out.print(c);
}
@Override
protected void printThisAfter() {
// nop
}
}

32
composite/src/main/java/com/iluwatar/composite/LetterComposite.java
View File

@ -10,25 +10,25 @@ import java.util.List;
*/
public abstract class LetterComposite {
private List<LetterComposite> children = new ArrayList<LetterComposite>();
private List<LetterComposite> children = new ArrayList<LetterComposite>();
public void add(LetterComposite letter) {
children.add(letter);
}
public void add(LetterComposite letter) {
children.add(letter);
}
public int count() {
return children.size();
}
public int count() {
return children.size();
}
protected abstract void printThisBefore();
protected abstract void printThisBefore();
protected abstract void printThisAfter();
protected abstract void printThisAfter();
public void print() {
printThisBefore();
for (LetterComposite letter : children) {
letter.print();
}
printThisAfter();
}
public void print() {
printThisBefore();
for (LetterComposite letter : children) {
letter.print();
}
printThisAfter();
}
}

67
composite/src/main/java/com/iluwatar/composite/Messenger.java
View File

@ -11,48 +11,47 @@ import java.util.List;
*/
public class Messenger {
LetterComposite messageFromOrcs() {
LetterComposite messageFromOrcs() {
List<Word> words = new ArrayList<Word>();
List<Word> words = new ArrayList<Word>();
words.add(new Word(Arrays.asList(new Letter('W'), new Letter('h'),
new Letter('e'), new Letter('r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'),
new Letter('e'), new Letter('r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('a'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('h'),
new Letter('i'), new Letter('p'))));
words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'),
new Letter('e'), new Letter('r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('a'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('a'),
new Letter('y'))));
words.add(new Word(Arrays.asList(new Letter('W'), new Letter('h'), new Letter('e'), new Letter(
'r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter(
'r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('a'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('h'), new Letter('i'), new Letter(
'p'))));
words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter(
'r'), new Letter('e'))));
words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('a'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('a'), new Letter('y'))));
return new Sentence(words);
return new Sentence(words);
}
}
LetterComposite messageFromElves() {
LetterComposite messageFromElves() {
List<Word> words = new ArrayList<Word>();
List<Word> words = new ArrayList<Word>();
words.add(new Word(Arrays.asList(new Letter('M'), new Letter('u'),
new Letter('c'), new Letter('h'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('i'),
new Letter('n'), new Letter('d'))));
words.add(new Word(Arrays.asList(new Letter('p'), new Letter('o'),
new Letter('u'), new Letter('r'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('f'), new Letter('r'),
new Letter('o'), new Letter('m'))));
words.add(new Word(Arrays.asList(new Letter('y'), new Letter('o'),
new Letter('u'), new Letter('r'))));
words.add(new Word(Arrays.asList(new Letter('m'), new Letter('o'),
new Letter('u'), new Letter('t'), new Letter('h'))));
words.add(new Word(Arrays.asList(new Letter('M'), new Letter('u'), new Letter('c'), new Letter(
'h'))));
words.add(new Word(Arrays.asList(new Letter('w'), new Letter('i'), new Letter('n'), new Letter(
'd'))));
words.add(new Word(Arrays.asList(new Letter('p'), new Letter('o'), new Letter('u'), new Letter(
'r'), new Letter('s'))));
words.add(new Word(Arrays.asList(new Letter('f'), new Letter('r'), new Letter('o'), new Letter(
'm'))));
words.add(new Word(Arrays.asList(new Letter('y'), new Letter('o'), new Letter('u'), new Letter(
'r'))));
words.add(new Word(Arrays.asList(new Letter('m'), new Letter('o'), new Letter('u'), new Letter(
't'), new Letter('h'))));
return new Sentence(words);
return new Sentence(words);
}
}
}

27
composite/src/main/java/com/iluwatar/composite/Sentence.java
View File

@ -9,20 +9,19 @@ import java.util.List;
*/
public class Sentence extends LetterComposite {
public Sentence(List<Word> words) {
for (Word w : words) {
this.add(w);
}
}
public Sentence(List<Word> words) {
for (Word w : words) {
this.add(w);
}
}
@Override
protected void printThisBefore() {
// nop
}
@Override
protected void printThisAfter() {
System.out.print(".");
}
@Override
protected void printThisBefore() {
// nop
}
@Override
protected void printThisAfter() {
System.out.print(".");
}
}

27
composite/src/main/java/com/iluwatar/composite/Word.java
View File

@ -9,20 +9,19 @@ import java.util.List;
*/
public class Word extends LetterComposite {
public Word(List<Letter> letters) {
for (Letter l : letters) {
this.add(l);
}
}
public Word(List<Letter> letters) {
for (Letter l : letters) {
this.add(l);
}
}
@Override
protected void printThisBefore() {
System.out.print(" ");
}
@Override
protected void printThisAfter() {
// nop
}
@Override
protected void printThisBefore() {
System.out.print(" ");
}
@Override
protected void printThisAfter() {
// nop
}
}

10
composite/src/test/java/com/iluwatar/composite/AppTest.java
View File

@ -11,9 +11,9 @@ import com.iluwatar.composite.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

86
dao/src/main/java/com/iluwatar/dao/App.java
View File

@ -7,53 +7,55 @@ import org.apache.log4j.Logger;
/**
*
* Data Access Object (DAO) is an object that provides an abstract interface to some type of database or other
* persistence mechanism. By mapping application calls to the persistence layer, DAO provide some specific data
* operations without exposing details of the database. This isolation supports the Single responsibility principle.
* It separates what data accesses the application needs, in terms of domain-specific objects and data types
* (the public interface of the DAO), from how these needs can be satisfied with a specific DBMS.
* Data Access Object (DAO) is an object that provides an abstract interface to some type of
* database or other persistence mechanism. By mapping application calls to the persistence layer,
* DAO provide some specific data operations without exposing details of the database. This
* isolation supports the Single responsibility principle. It separates what data accesses the
* application needs, in terms of domain-specific objects and data types (the public interface of
* the DAO), from how these needs can be satisfied with a specific DBMS.
* <p>
* With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without directly
* interacting with the data. The below example demonstrates basic CRUD operations: select, add, update, and delete.
* With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without
* directly interacting with the data. The below example demonstrates basic CRUD operations: select,
* add, update, and delete.
*
*/
public class App {
private static Logger LOGGER = Logger.getLogger(App.class);
private static Logger LOGGER = Logger.getLogger(App.class);
/**
* Program entry point.
*
* @param args command line args.
*/
public static void main(final String[] args) {
final CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
LOGGER.info("customerDao.getCusterById(2): " + customerDao.getCustomerById(2));
final Customer customer = new Customer(4, "Dan", "Danson");
customerDao.addCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
customer.setFirstName("Daniel");
customer.setLastName("Danielson");
customerDao.updateCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
customerDao.deleteCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
}
/**
* Program entry point.
*
* @param args command line args.
*/
public static void main(final String[] args) {
final CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
LOGGER.info("customerDao.getCusterById(2): " + customerDao.getCustomerById(2));
final Customer customer = new Customer(4, "Dan", "Danson");
customerDao.addCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
customer.setFirstName("Daniel");
customer.setLastName("Danielson");
customerDao.updateCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
customerDao.deleteCustomer(customer);
LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
}
/**
* Generate customers.
*
* @return list of customers.
*/
public static List<Customer> generateSampleCustomers() {
final Customer customer1 = new Customer(1, "Adam", "Adamson");
final Customer customer2 = new Customer(2, "Bob", "Bobson");
final Customer customer3 = new Customer(3, "Carl", "Carlson");
final List<Customer> customers = new ArrayList<Customer>();
customers.add(customer1);
customers.add(customer2);
customers.add(customer3);
return customers;
}
/**
* Generate customers.
*
* @return list of customers.
*/
public static List<Customer> generateSampleCustomers() {
final Customer customer1 = new Customer(1, "Adam", "Adamson");
final Customer customer2 = new Customer(2, "Bob", "Bobson");
final Customer customer3 = new Customer(3, "Carl", "Carlson");
final List<Customer> customers = new ArrayList<Customer>();
customers.add(customer1);
customers.add(customer2);
customers.add(customer3);
return customers;
}
}

52
decorator/src/main/java/com/iluwatar/decorator/App.java
View File

@ -2,37 +2,37 @@ package com.iluwatar.decorator;
/**
*
* The Decorator pattern is a more flexible alternative to subclassing. The Decorator
* class implements the same interface as the target and uses composition to
* "decorate" calls to the target. Using the Decorator pattern it is possible to
* change the behavior of the class during runtime.
* The Decorator pattern is a more flexible alternative to subclassing. The Decorator class
* implements the same interface as the target and uses composition to "decorate" calls to the
* target. Using the Decorator pattern it is possible to change the behavior of the class during
* runtime.
* <p>
* In this example we show how the simple {@link Troll} first attacks and then
* flees the battle. Then we decorate the {@link Troll} with a {@link SmartTroll}
* and perform the attack again. You can see how the behavior changes after the
* decoration.
* In this example we show how the simple {@link Troll} first attacks and then flees the battle.
* Then we decorate the {@link Troll} with a {@link SmartTroll} and perform the attack again. You
* can see how the behavior changes after the decoration.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
// simple troll
System.out.println("A simple looking troll approaches.");
Hostile troll = new Troll();
troll.attack();
troll.fleeBattle();
System.out.printf("Simple troll power %d.\n", troll.getAttackPower());
// simple troll
System.out.println("A simple looking troll approaches.");
Hostile troll = new Troll();
troll.attack();
troll.fleeBattle();
System.out.printf("Simple troll power %d.\n", troll.getAttackPower());
// change the behavior of the simple troll by adding a decorator
System.out.println("\nA smart looking troll surprises you.");
Hostile smart = new SmartTroll(troll);
smart.attack();
smart.fleeBattle();
System.out.printf("Smart troll power %d.\n", smart.getAttackPower());
}
// change the behavior of the simple troll by adding a decorator
System.out.println("\nA smart looking troll surprises you.");
Hostile smart = new SmartTroll(troll);
smart.attack();
smart.fleeBattle();
System.out.printf("Smart troll power %d.\n", smart.getAttackPower());
}
}

6
decorator/src/main/java/com/iluwatar/decorator/Hostile.java
View File

@ -7,10 +7,10 @@ package com.iluwatar.decorator;
*/
public interface Hostile {
void attack();
void attack();
int getAttackPower();
int getAttackPower();
void fleeBattle();
void fleeBattle();
}

46
decorator/src/main/java/com/iluwatar/decorator/SmartTroll.java
View File

@ -1,36 +1,34 @@
package com.iluwatar.decorator;
/**
* SmartTroll is a decorator for {@link Hostile} objects.
* The calls to the {@link Hostile} interface are intercepted
* and decorated. Finally the calls are delegated
* to the decorated {@link Hostile} object.
* SmartTroll is a decorator for {@link Hostile} objects. The calls to the {@link Hostile} interface
* are intercepted and decorated. Finally the calls are delegated to the decorated {@link Hostile}
* object.
*
*/
public class SmartTroll implements Hostile {
private Hostile decorated;
private Hostile decorated;
public SmartTroll(Hostile decorated) {
this.decorated = decorated;
}
public SmartTroll(Hostile decorated) {
this.decorated = decorated;
}
@Override
public void attack() {
System.out.println("The troll throws a rock at you!");
decorated.attack();
}
@Override
public void attack() {
System.out.println("The troll throws a rock at you!");
decorated.attack();
}
@Override
public int getAttackPower() {
// decorated troll power + 20 because it is smart
return decorated.getAttackPower() + 20;
}
@Override
public void fleeBattle() {
System.out.println("The troll calls for help!");
decorated.fleeBattle();
}
@Override
public int getAttackPower() {
// decorated troll power + 20 because it is smart
return decorated.getAttackPower() + 20;
}
@Override
public void fleeBattle() {
System.out.println("The troll calls for help!");
decorated.fleeBattle();
}
}

21
decorator/src/main/java/com/iluwatar/decorator/Troll.java
View File

@ -7,17 +7,16 @@ package com.iluwatar.decorator;
*/
public class Troll implements Hostile {
public void attack() {
System.out.println("The troll swings at you with a club!");
}
public void attack() {
System.out.println("The troll swings at you with a club!");
}
@Override
public int getAttackPower() {
return 10;
}
public void fleeBattle() {
System.out.println("The troll shrieks in horror and runs away!");
}
@Override
public int getAttackPower() {
return 10;
}
public void fleeBattle() {
System.out.println("The troll shrieks in horror and runs away!");
}
}

10
decorator/src/test/java/com/iluwatar/decorator/AppTest.java
View File

@ -11,9 +11,9 @@ import com.iluwatar.decorator.App;
*/
public class AppTest {
@Test
public void test() {
String[] args = {};
App.main(args);
}
@Test
public void test() {
String[] args = {};
App.main(args);
}
}

23
dependency-injection/src/main/java/com/iluwatar/dependency/injection/AdvancedWizard.java
View File

@ -2,21 +2,20 @@ package com.iluwatar.dependency.injection;
/**
*
* AdvancedWizard implements inversion of control.
* It depends on abstraction that can be injected through
* its constructor.
* AdvancedWizard implements inversion of control. It depends on abstraction that can be injected
* through its constructor.
*
*/
public class AdvancedWizard implements Wizard {
private Tobacco tobacco;
public AdvancedWizard(Tobacco tobacco) {
this.tobacco = tobacco;
}
private Tobacco tobacco;
@Override
public void smoke() {
tobacco.smoke(this);
}
public AdvancedWizard(Tobacco tobacco) {
this.tobacco = tobacco;
}
@Override
public void smoke() {
tobacco.smoke(this);
}
}

65
dependency-injection/src/main/java/com/iluwatar/dependency/injection/App.java
View File

@ -5,40 +5,41 @@ import com.google.inject.Injector;
/**
*
* Dependency Injection pattern deals with how objects handle their dependencies. The pattern
* Dependency Injection pattern deals with how objects handle their dependencies. The pattern
* implements so called inversion of control principle. Inversion of control has two specific rules:
* - High-level modules should not depend on low-level modules. Both should depend on abstractions.
* - Abstractions should not depend on details. Details should depend on abstractions.
* <p>
* In this example we show you three different wizards. The first one ({@link SimpleWizard}) is a naive
* implementation violating the inversion of control principle. It depends directly on a concrete
* implementation which cannot be changed.
* <p>
* The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete implementation
* but abstraction. It utilizes Dependency Injection pattern allowing its {@link Tobacco} dependency to be
* injected through its constructor. This way, handling the dependency is no longer the wizard's
* responsibility. It is resolved outside the wizard class.
* <p>
* The third example takes the pattern a step further. It uses Guice framework for Dependency Injection.
* {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then used to create
* {@link GuiceWizard} object with correct dependencies.
* - High-level modules should not depend on low-level modules. Both should depend on abstractions.
* - Abstractions should not depend on details. Details should depend on abstractions.
* <p>
* In this example we show you three different wizards. The first one ({@link SimpleWizard}) is a
* naive implementation violating the inversion of control principle. It depends directly on a
* concrete implementation which cannot be changed.
* <p>
* The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete
* implementation but abstraction. It utilizes Dependency Injection pattern allowing its
* {@link Tobacco} dependency to be injected through its constructor. This way, handling the
* dependency is no longer the wizard's responsibility. It is resolved outside the wizard class.
* <p>
* The third example takes the pattern a step further. It uses Guice framework for Dependency
* Injection. {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then
* used to create {@link GuiceWizard} object with correct dependencies.
*
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main( String[] args ) {
SimpleWizard simpleWizard = new SimpleWizard();
simpleWizard.smoke();
AdvancedWizard advancedWizard = new AdvancedWizard(new SecondBreakfastTobacco());
advancedWizard.smoke();
Injector injector = Guice.createInjector(new TobaccoModule());
GuiceWizard guiceWizard = injector.getInstance(GuiceWizard.class);
guiceWizard.smoke();
}
/**
* Program entry point
*
* @param args command line args
*/
public static void main(String[] args) {
SimpleWizard simpleWizard = new SimpleWizard();
simpleWizard.smoke();
AdvancedWizard advancedWizard = new AdvancedWizard(new SecondBreakfastTobacco());
advancedWizard.smoke();
Injector injector = Guice.createInjector(new TobaccoModule());
GuiceWizard guiceWizard = injector.getInstance(GuiceWizard.class);
guiceWizard.smoke();
}
}

27
dependency-injection/src/main/java/com/iluwatar/dependency/injection/GuiceWizard.java
View File

@ -4,22 +4,21 @@ import javax.inject.Inject;
/**
*
* GuiceWizard implements inversion of control.
* Its dependencies are injected through its constructor
* by Guice framework.
* GuiceWizard implements inversion of control. Its dependencies are injected through its
* constructor by Guice framework.
*
*/
public class GuiceWizard implements Wizard {
private Tobacco tobacco;
@Inject
public GuiceWizard(Tobacco tobacco) {
this.tobacco = tobacco;
}
@Override
public void smoke() {
tobacco.smoke(this);
}
private Tobacco tobacco;
@Inject
public GuiceWizard(Tobacco tobacco) {
this.tobacco = tobacco;
}
@Override
public void smoke() {
tobacco.smoke(this);
}
}

16
dependency-injection/src/main/java/com/iluwatar/dependency/injection/SimpleWizard.java
View File

@ -2,15 +2,15 @@ package com.iluwatar.dependency.injection;
/**
*
* Naive Wizard implementation violating the inversion of control principle.
* It should depend on abstraction instead.
* Naive Wizard implementation violating the inversion of control principle. It should depend on
* abstraction instead.
*
*/
public class SimpleWizard implements Wizard {
private OldTobyTobacco tobacco = new OldTobyTobacco();
public void smoke() {
tobacco.smoke(this);
}
private OldTobyTobacco tobacco = new OldTobyTobacco();
public void smoke() {
tobacco.smoke(this);
}
}

9
dependency-injection/src/main/java/com/iluwatar/dependency/injection/Tobacco.java
View File

@ -6,8 +6,9 @@ package com.iluwatar.dependency.injection;
*
*/
public abstract class Tobacco {
public void smoke(Wizard wizard) {
System.out.println(String.format("%s smoking %s", wizard.getClass().getSimpleName(), this.getClass().getSimpleName()));
}
public void smoke(Wizard wizard) {
System.out.println(String.format("%s smoking %s", wizard.getClass().getSimpleName(), this
.getClass().getSimpleName()));
}
}

8
dependency-injection/src/main/java/com/iluwatar/dependency/injection/TobaccoModule.java
View File

@ -9,8 +9,8 @@ import com.google.inject.AbstractModule;
*/
public class TobaccoModule extends AbstractModule {
@Override
protected void configure() {
bind(Tobacco.class).to(RivendellTobacco.class);
}
@Override
protected void configure() {
bind(Tobacco.class).to(RivendellTobacco.class);
}
}

4
dependency-injection/src/main/java/com/iluwatar/dependency/injection/Wizard.java
View File

@ -6,7 +6,7 @@ package com.iluwatar.dependency.injection;
*
*/
public interface Wizard {
void smoke();
void smoke();
}

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