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Java 11 migration: patterns (t-v) (#1085)

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* Moves visitor pattern to java 11

* Moves value-object pattern to java 11

* Moves unit-of-work pattern to java 11

* Moves typeobjectpattern pattern to java 11

* Moves twin pattern to java 11

* Moves trampoline pattern to java 11

* Moves tolerant-reader pattern to java 11

* Moves tls pattern to java 11

* Moves throttling pattern to java 11

* Moves thread-pool pattern to java 11

* Moves template-method pattern to java 11
This commit is contained in:
Anurag Agarwal
2019-11-14 11:12:05 +05:30
committed by Ilkka Seppälä
parent 160b737dcc
commit 50467c9e76
45 changed files with 379 additions and 422 deletions
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44
tls/src/main/java/com/iluwatar/tls/App.java
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@ -24,10 +24,7 @@
package com.iluwatar.tls;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -71,20 +68,20 @@ public class App {
* @param args command line args
*/
public static void main(String[] args) {
int counterDateValues = 0;
int counterExceptions = 0;
var counterDateValues = 0;
var counterExceptions = 0;
// Create a callable
DateFormatCallable callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
var callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
// start 4 threads, each using the same Callable instance
ExecutorService executor = Executors.newCachedThreadPool();
var executor = Executors.newCachedThreadPool();
Future<Result> futureResult1 = executor.submit(callableDf);
Future<Result> futureResult2 = executor.submit(callableDf);
Future<Result> futureResult3 = executor.submit(callableDf);
Future<Result> futureResult4 = executor.submit(callableDf);
var futureResult1 = executor.submit(callableDf);
var futureResult2 = executor.submit(callableDf);
var futureResult3 = executor.submit(callableDf);
var futureResult4 = executor.submit(callableDf);
try {
Result[] result = new Result[4];
var result = new Result[4];
result[0] = futureResult1.get();
result[1] = futureResult2.get();
result[2] = futureResult3.get();
@ -92,9 +89,9 @@ public class App {
// Print results of thread executions (converted dates and raised exceptions)
// and count them
for (int i = 0; i < result.length; i++) {
counterDateValues = counterDateValues + printAndCountDates(result[i]);
counterExceptions = counterExceptions + printAndCountExceptions(result[i]);
for (var value : result) {
counterDateValues = counterDateValues + printAndCountDates(value);
counterExceptions = counterExceptions + printAndCountExceptions(value);
}
// a correct run should deliver 20 times 15.12.2015
@ -115,15 +112,16 @@ public class App {
*/
private static int printAndCountDates(Result res) {
// a correct run should deliver 5 times 15.12.2015 per each thread
int counter = 0;
for (Date dt : res.getDateList()) {
var counter = 0;
for (var dt : res.getDateList()) {
counter++;
Calendar cal = Calendar.getInstance();
var cal = Calendar.getInstance();
cal.setTime(dt);
// Formatted output of the date value: DD.MM.YYYY
LOGGER.info(
cal.get(Calendar.DAY_OF_MONTH) + "." + cal.get(Calendar.MONTH) + "." + +cal
.get(Calendar.YEAR));
LOGGER.info(cal.get(Calendar.DAY_OF_MONTH) + "."
+ cal.get(Calendar.MONTH) + "."
+ cal.get(Calendar.YEAR)
);
}
return counter;
}
@ -136,8 +134,8 @@ public class App {
*/
private static int printAndCountExceptions(Result res) {
// a correct run shouldn't deliver any exception
int counter = 0;
for (String ex : res.getExceptionList()) {
var counter = 0;
for (var ex : res.getExceptionList()) {
counter++;
LOGGER.info(ex);
}

19
tls/src/main/java/com/iluwatar/tls/DateFormatCallable.java
View File

@ -26,6 +26,7 @@ package com.iluwatar.tls;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.concurrent.Callable;
import java.util.stream.IntStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -58,13 +59,10 @@ public class DateFormatCallable implements Callable<Result> {
* @param inDateValue string date value, e.g. "21/06/2016"
*/
public DateFormatCallable(String inDateFormat, String inDateValue) {
final String idf = inDateFormat; //TLTL
this.df = new ThreadLocal<DateFormat>() { //TLTL
@Override //TLTL
protected DateFormat initialValue() { //TLTL
return new SimpleDateFormat(idf); //TLTL
} //TLTL
}; //TLTL
final var idf = inDateFormat; //TLTL
this.df = ThreadLocal.withInitial(() -> { //TLTL
return new SimpleDateFormat(idf); //TLTL
}); //TLTL
// this.df = new SimpleDateFormat(inDateFormat); //NTLNTL
this.dateValue = inDateValue;
}
@ -72,10 +70,10 @@ public class DateFormatCallable implements Callable<Result> {
@Override
public Result call() {
LOGGER.info(Thread.currentThread() + " started executing...");
Result result = new Result();
var result = new Result();
// Convert date value to date 5 times
for (int i = 1; i <= 5; i++) {
IntStream.rangeClosed(1, 5).forEach(i -> {
try {
// this is the statement where it is important to have the
// instance of SimpleDateFormat locally
@ -86,8 +84,7 @@ public class DateFormatCallable implements Callable<Result> {
// write the Exception to a list and continue work
result.getExceptionList().add(e.getClass() + ": " + e.getMessage());
}
}
});
LOGGER.info(Thread.currentThread() + " finished processing part of the thread");

4
tls/src/main/java/com/iluwatar/tls/Result.java
View File

@ -39,11 +39,11 @@ import java.util.List;
*/
public class Result {
// A list to collect the date values created in one thread
private List<Date> dateList = new ArrayList<Date>();
private List<Date> dateList = new ArrayList<>();
// A list to collect Exceptions thrown in one threads (should be none in
// this example)
private List<String> exceptionList = new ArrayList<String>();
private List<String> exceptionList = new ArrayList<>();
/**
* Get list of date values collected within a thread execution.

8
tls/src/test/java/com/iluwatar/tls/AppTest.java
View File

@ -27,14 +27,12 @@ import org.junit.jupiter.api.Test;
/**
* Tests that thread local storage example runs without errors.
*
* @author Thomas Bauer, January 2017
*
* @author Thomas Bauer, January 2017
*/
public class AppTest {
@Test
public void test() throws Exception {
String[] args = {};
App.main(args);
public void test() {
App.main(new String[]{});
}
}

88
tls/src/test/java/com/iluwatar/tls/DateFormatCallableTest.java
View File

@ -23,65 +23,62 @@
package com.iluwatar.tls;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.fail;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.concurrent.Executors;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
/**
*
* Test of the Callable
*
* In this test {@link DateFormatCallable} is tested with only one thread (i.e. without concurrency situation)
* <p>
* After a successful run 5 date values should be in the result object. All dates should have
* the same value (15.11.2015). To avoid problems with time zone not the date instances themselves
* are compared by the test. For the test the dates are converted into string format DD.MM.YYY
* In this test {@link DateFormatCallable} is tested with only one thread (i.e. without concurrency
* situation)
* <p>
* Additionally the number of list entries are tested for both the list with the date values
* and the list with the exceptions
*
* @author Thomas Bauer, January 2017
* After a successful run 5 date values should be in the result object. All dates should have the
* same value (15.11.2015). To avoid problems with time zone not the date instances themselves are
* compared by the test. For the test the dates are converted into string format DD.MM.YYY
* <p>
* Additionally the number of list entries are tested for both the list with the date values and the
* list with the exceptions
*
* @author Thomas Bauer, January 2017
*/
public class DateFormatCallableTest {
// Class variables used in setup() have to be static because setup() has to be static
/**
* Result object given back by DateFormatCallable
* -- Array with converted date values
* -- Array with thrown exceptions
* Result object given back by DateFormatCallable -- Array with converted date values -- Array
* with thrown exceptions
*/
static Result result;
private static Result result;
/**
* The date values created by the run of of DateFormatRunnalbe. List will be filled in the setup() method
* The date values created by the run of of DateFormatRunnalbe. List will be filled in the setup()
* method
*/
static List<String> createdDateValues = new ArrayList<String>();
private static List<String> createdDateValues = new ArrayList<>();
/**
* Expected number of date values in the date value list created by the run of DateFormatRunnalbe
*/
int expectedCounterDateValues = 5;
private int expectedCounterDateValues = 5;
/**
* Expected number of exceptions in the exception list created by the run of DateFormatRunnalbe.
* Expected number of exceptions in the exception list created by the run of DateFormatRunnalbe.
*/
int expectedCounterExceptions = 0;
private int expectedCounterExceptions = 0;
/**
* Expected content of the list containing the date values created by the run of DateFormatRunnalbe
* Expected content of the list containing the date values created by the run of
* DateFormatRunnalbe
*/
List<String> expectedDateValues = List.of("15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015");
private List<String> expectedDateValues =
List.of("15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015");
/**
* Run Callable and prepare results for usage in the test methods
@ -89,10 +86,10 @@ public class DateFormatCallableTest {
@BeforeAll
public static void setup() {
// Create a callable
DateFormatCallable callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
var callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
// start thread using the Callable instance
ExecutorService executor = Executors.newCachedThreadPool();
Future<Result> futureResult = executor.submit(callableDf);
var executor = Executors.newCachedThreadPool();
var futureResult = executor.submit(callableDf);
try {
result = futureResult.get();
createdDateValues = convertDatesToString(result);
@ -107,18 +104,22 @@ public class DateFormatCallableTest {
if (res == null || res.getDateList() == null || res.getDateList().size() == 0) {
return null;
}
List<String> returnList = new ArrayList<String>();
var returnList = new ArrayList<String>();
for (Date dt : res.getDateList()) {
Calendar cal = Calendar.getInstance();
for (var dt : res.getDateList()) {
var cal = Calendar.getInstance();
cal.setTime(dt);
returnList.add(cal.get(Calendar.DAY_OF_MONTH) + "." + cal.get(Calendar.MONTH) + "." + cal.get(Calendar.YEAR));
returnList.add(cal.get(Calendar.DAY_OF_MONTH) + "."
+ cal.get(Calendar.MONTH) + "."
+ cal.get(Calendar.YEAR)
);
}
return returnList;
}
/**
* Test date values after the run of DateFormatRunnalbe. A correct run should deliver 5 times 15.12.2015
* Test date values after the run of DateFormatRunnalbe. A correct run should deliver 5 times
* 15.12.2015
*/
@Test
public void testDateValues() {
@ -126,7 +127,8 @@ public class DateFormatCallableTest {
}
/**
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should deliver 5 date values
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should
* deliver 5 date values
*/
@Test
public void testCounterDateValues() {
@ -134,8 +136,8 @@ public class DateFormatCallableTest {
}
/**
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should deliver
* no exceptions
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should
* deliver no exceptions
*/
@Test
public void testCounterExceptions() {

65
tls/src/test/java/com/iluwatar/tls/DateFormatCallableTestIncorrectDateFormat.java
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@ -23,63 +23,55 @@
package com.iluwatar.tls;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.fail;
import java.util.List;
import java.util.concurrent.Executors;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
/**
*
* Test of the Callable
*
* In this test {@link DateFormatCallable} is tested with only one thread (i.e. without concurrency situation)
* <p>
* An incorrect formatted date is passed to the Callable
* After a successful run 0 date values and 5 exceptions should be in the result object.
*
* @author Thomas Bauer, January 2017
* In this test {@link DateFormatCallable} is tested with only one thread (i.e. without concurrency
* situation)
* <p>
* An incorrect formatted date is passed to the Callable After a successful run 0 date values and 5
* exceptions should be in the result object.
*
* @author Thomas Bauer, January 2017
*/
public class DateFormatCallableTestIncorrectDateFormat {
// Class variables used in setup() have to be static because setup() has to be static
/**
* Result object given back by DateFormatCallable
* -- Array with converted date values
* -- Array with thrown exceptions
* Result object given back by DateFormatCallable -- Array with converted date values -- Array
* with thrown exceptions
*/
static Result result;
/**
* The date values created by the run of DateFormatRunnalbe. List will be filled in the setup() method
*/
static List<String> createdExceptions = new ArrayList<String>();
private static Result result;
/**
* Expected number of date values in the date value list created by the run of DateFormatRunnalbe
*/
int expectedCounterDateValues = 0;
private int expectedCounterDateValues = 0;
/**
* Expected number of exceptions in the exception list created by the run of DateFormatRunnalbe.
* Expected number of exceptions in the exception list created by the run of DateFormatRunnalbe.
*/
int expectedCounterExceptions = 5;
private int expectedCounterExceptions = 5;
/**
* Expected content of the list containing the exceptions created by the run of DateFormatRunnalbe
* Expected content of the list containing the exceptions created by the run of
* DateFormatRunnalbe
*/
List<String> expectedExceptions = List.of("class java.text.ParseException: Unparseable date: \"15.12.2015\"",
private List<String> expectedExceptions = List.of(
"class java.text.ParseException: Unparseable date: \"15.12.2015\"",
"class java.text.ParseException: Unparseable date: \"15.12.2015\"",
"class java.text.ParseException: Unparseable date: \"15.12.2015\"",
"class java.text.ParseException: Unparseable date: \"15.12.2015\"");
"class java.text.ParseException: Unparseable date: \"15.12.2015\"",
"class java.text.ParseException: Unparseable date: \"15.12.2015\""
);
/**
* Run Callable and prepare results for usage in the test methods
@ -87,10 +79,10 @@ public class DateFormatCallableTestIncorrectDateFormat {
@BeforeAll
public static void setup() {
// Create a callable. Pass a string date value not matching the format string
DateFormatCallable callableDf = new DateFormatCallable("dd/MM/yyyy", "15.12.2015");
var callableDf = new DateFormatCallable("dd/MM/yyyy", "15.12.2015");
// start thread using the Callable instance
ExecutorService executor = Executors.newCachedThreadPool();
Future<Result> futureResult = executor.submit(callableDf);
var executor = Executors.newCachedThreadPool();
var futureResult = executor.submit(callableDf);
try {
result = futureResult.get();
} catch (Exception e) {
@ -109,7 +101,8 @@ public class DateFormatCallableTestIncorrectDateFormat {
}
/**
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should deliver no date values
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should
* deliver no date values
*/
@Test
public void testCounterDateValues() {
@ -117,7 +110,7 @@ public class DateFormatCallableTestIncorrectDateFormat {
}
/**
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should
* deliver 5 exceptions
*/
@Test

104
tls/src/test/java/com/iluwatar/tls/DateFormatCallableTestMultiThread.java
View File

@ -23,69 +23,66 @@
package com.iluwatar.tls;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.fail;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.concurrent.Executors;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
/**
*
* Test of the Callable
*
* <p>
* In this test {@link DateFormatCallable} is used by 4 threads in parallel
* <p>
* After a successful run 5 date values should be in the result object of each thread. All dates
* After a successful run 5 date values should be in the result object of each thread. All dates
* should have the same value (15.11.2015). To avoid problems with time zone not the date instances
* themselves are compared by the test. For the test the dates are converted into string format DD.MM.YYY
* themselves are compared by the test. For the test the dates are converted into string format
* DD.MM.YYY
* <p>
* Additionally the number of list entries are tested for both the list with the date values
* and the list with the exceptions
*
* @author Thomas Bauer, January 2017
* Additionally the number of list entries are tested for both the list with the date values and the
* list with the exceptions
*
* @author Thomas Bauer, January 2017
*/
public class DateFormatCallableTestMultiThread {
// Class variables used in setup() have to be static because setup() has to be static
/**
* Result object given back by DateFormatCallable, one for each thread
* -- Array with converted date values
* -- Array with thrown exceptions
* Result object given back by DateFormatCallable, one for each thread -- Array with converted
* date values -- Array with thrown exceptions
*/
static Result[] result = new Result[4];
private static Result[] result = new Result[4];
/**
* The date values created by the run of of DateFormatRunnalbe. List will be filled in the setup() method
* The date values created by the run of of DateFormatRunnalbe. List will be filled in the setup()
* method
*/
@SuppressWarnings("serial")
static class StringArrayList extends ArrayList<String> {
private static class StringArrayList extends ArrayList<String> {
/* nothing needed here */
}
static List<String>[] createdDateValues = new StringArrayList[4];
private static List<String>[] createdDateValues = new StringArrayList[4];
/**
* Expected number of date values in the date value list created by each thread
*/
int expectedCounterDateValues = 5;
private int expectedCounterDateValues = 5;
/**
* Expected number of exceptions in the exception list created by each thread
* Expected number of exceptions in the exception list created by each thread
*/
int expectedCounterExceptions = 0;
private int expectedCounterExceptions = 0;
/**
* Expected content of the list containing the date values created by each thread
* Expected content of the list containing the date values created by each thread
*/
List<String> expectedDateValues = List.of("15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015");
private List<String> expectedDateValues =
List.of("15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015", "15.11.2015");
/**
* Run Callable and prepare results for usage in the test methods
@ -93,19 +90,19 @@ public class DateFormatCallableTestMultiThread {
@BeforeAll
public static void setup() {
// Create a callable
DateFormatCallable callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
var callableDf = new DateFormatCallable("dd/MM/yyyy", "15/12/2015");
// start thread using the Callable instance
ExecutorService executor = Executors.newCachedThreadPool();
Future<Result> futureResult1 = executor.submit(callableDf);
Future<Result> futureResult2 = executor.submit(callableDf);
Future<Result> futureResult3 = executor.submit(callableDf);
Future<Result> futureResult4 = executor.submit(callableDf);
var executor = Executors.newCachedThreadPool();
var futureResult1 = executor.submit(callableDf);
var futureResult2 = executor.submit(callableDf);
var futureResult3 = executor.submit(callableDf);
var futureResult4 = executor.submit(callableDf);
try {
result[0] = futureResult1.get();
result[1] = futureResult2.get();
result[2] = futureResult3.get();
result[3] = futureResult4.get();
for (int i = 0; i < result.length; i++) {
for (var i = 0; i < result.length; i++) {
createdDateValues[i] = convertDatesToString(result[i]);
}
} catch (Exception e) {
@ -119,46 +116,49 @@ public class DateFormatCallableTestMultiThread {
if (res == null || res.getDateList() == null || res.getDateList().size() == 0) {
return null;
}
List<String> returnList = new StringArrayList();
var returnList = new StringArrayList();
for (Date dt : res.getDateList()) {
Calendar cal = Calendar.getInstance();
for (var dt : res.getDateList()) {
var cal = Calendar.getInstance();
cal.setTime(dt);
returnList.add(cal.get(Calendar.DAY_OF_MONTH) + "." + cal.get(Calendar.MONTH) + "." + cal.get(Calendar.YEAR));
returnList.add(cal.get(Calendar.DAY_OF_MONTH) + "."
+ cal.get(Calendar.MONTH) + "."
+ cal.get(Calendar.YEAR)
);
}
return returnList;
}
/**
* Test date values after the run of DateFormatRunnalbe. A correct run should deliver 5 times 15.12.2015
* by each thread
* Test date values after the run of DateFormatRunnalbe. A correct run should deliver 5 times
* 15.12.2015 by each thread
*/
@Test
public void testDateValues() {
for (int i = 0; i < createdDateValues.length; i++) {
assertEquals(expectedDateValues, createdDateValues[i]);
for (var createdDateValue : createdDateValues) {
assertEquals(expectedDateValues, createdDateValue);
}
}
/**
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should
* Test number of dates in the list after the run of DateFormatRunnalbe. A correct run should
* deliver 5 date values by each thread
*/
@Test
public void testCounterDateValues() {
for (int i = 0; i < result.length; i++) {
assertEquals(expectedCounterDateValues, result[i].getDateList().size());
for (var value : result) {
assertEquals(expectedCounterDateValues, value.getDateList().size());
}
}
/**
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should
* Test number of Exceptions in the list after the run of DateFormatRunnalbe. A correct run should
* deliver no exceptions
*/
@Test
public void testCounterExceptions() {
for (int i = 0; i < result.length; i++) {
assertEquals(expectedCounterExceptions, result[i].getExceptionList().size());
for (var value : result) {
assertEquals(expectedCounterExceptions, value.getExceptionList().size());
}
}
}