diff --git a/README.md b/README.md
index d5c2a2e82..2118fb5ef 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,14 @@
+## Introduction
+
+Design patterns are formalized best practices that the programmer can use to solve common problems when designing an application or system.
+
+Design patterns can speed up the development process by providing tested, proven development paradigms.
+
+Reusing design patterns helps to prevent subtle issues that can cause major problems, and it also improves code readability for coders and architects who are familiar with the patterns.
+
## <a name="list-of-design-patterns">List of Design Patterns</a>
### Creational Patterns
@@ -14,8 +22,9 @@ Creational design patterns abstract the instantiation process. They help make a
* [Builder](#builder)
* [Factory Method](#factory-method)
* [Prototype](#prototype)
+* [Property](#property)
* [Singleton](#singleton)
-
+
### Structural Patterns
Structural patterns are concerned with how classes and objects are composed to form larger structures.
@@ -50,6 +59,7 @@ Behavioral patterns are concerned with algorithms and the assignment of responsi
* [Double Checked Locking](#double-checked-locking)
* [Null Object](#null-object)
* [Callback](#callback)
+* [Execute Around](#execute-around)
### Presentation Tier Patterns
@@ -427,6 +437,7 @@ Presentation Tier patterns are the top-most level of the application, this is co
**Applicability:** Use the Callback pattern when
* When some arbitrary synchronous or asynchronous action must be performed after execution of some defined activity.
+<<<<<<< HEAD
## <a name="intercepting-filter">Intercepting Filter</a> [↑](#list-of-design-patterns)
**Intent:** Provide pluggable filters to conduct necessary pre-processing and post-processing to requests from a client to a target
@@ -436,6 +447,29 @@ Presentation Tier patterns are the top-most level of the application, this is co
* a system uses pre-processing or post-processing requests
* a system should do the authentication/ authorization/ logging or tracking of request and then pass the requests to corresponding handlers
* you want a modular approach to configuring pre-processing and post-processing schemes
+=======
+**Real world examples:**
+* [CyclicBarrier] (http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/CyclicBarrier.html#CyclicBarrier%28int,%20java.lang.Runnable%29) constructor can accept callback that will be triggered every time when barrier is tripped.
+
+## <a name="execute-around">Execute Around</a> [↑](#list-of-design-patterns)
+**Intent:** Execute Around idiom frees the user from certain actions that should always be executed before and after the business method. A good example of this is resource allocation and deallocation leaving the user to specify only what to do with the resource.
+
+
+
+**Applicability:** Use the Execute Around idiom when
+* You use an API that requires methods to be called in pairs such as open/close or allocate/deallocate.
+
+## <a name="property">Property</a> [↑](#list-of-design-patterns)
+**Intent:** Create hierarchy of objects and new objects using already existing objects as parents.
+
+
+
+**Applicability:** Use the Property pattern when
+* when you like to have objects with dynamic set of fields and prototype inheritance
+
+**Real world examples:**
+* [JavaScript](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain) prototype inheritance
+>>>>>>> origin/master
# Frequently asked questions
@@ -481,8 +515,14 @@ The difference is the intent of the patterns. While Proxy controls access to the
* [Let’s Modify the Objects-First Approach into Design-Patterns-First](http://edu.pecinovsky.cz/papers/2006_ITiCSE_Design_Patterns_First.pdf)
* [Pattern Languages of Program Design](http://www.amazon.com/Pattern-Languages-Program-Design-Coplien/dp/0201607344/ref=sr_1_1)
* [Martin Fowler - Event Aggregator](http://martinfowler.com/eaaDev/EventAggregator.html)
+<<<<<<< HEAD
* [TutorialsPoint - Intercepting Filter](http://www.tutorialspoint.com/design_pattern/intercepting_filter_pattern.htm)
* [Presentation Tier Pattern](http://www.javagyan.com/tutorials/corej2eepatterns/presentation-tier-patterns)
+=======
+* [Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions](http://www.amazon.com/Functional-Programming-Java-Harnessing-Expressions/dp/1937785467/ref=sr_1_1)
+
+
+>>>>>>> origin/master
# License
diff --git a/callback/src/main/java/com/iluwatar/App.java b/callback/src/main/java/com/iluwatar/App.java
index 6a36d66d7..2d79d8edf 100644
--- a/callback/src/main/java/com/iluwatar/App.java
+++ b/callback/src/main/java/com/iluwatar/App.java
@@ -1,7 +1,7 @@
package com.iluwatar;
/**
- * Callback pattern is more native for dynamic languages where function are first-class citizen.
+ * Callback pattern is more native for functional languages where function is treated as first-class citizen.
* Prior to Java8 can be simulated using simple (alike command) interfaces.
*/
public class App {
diff --git a/execute-around/execute-around.png b/execute-around/execute-around.png
new file mode 100644
index 000000000..fc048919d
Binary files /dev/null and b/execute-around/execute-around.png differ
diff --git a/execute-around/execute-around.ucls b/execute-around/execute-around.ucls
new file mode 100644
index 000000000..680334e9b
--- /dev/null
+++ b/execute-around/execute-around.ucls
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true"
+ realizations="true" associations="true" dependencies="false" nesting-relationships="true">
+ <class id="1" language="java" name="com.iluwatar.SimpleFileWriter" project="execute-around"
+ file="/execute-around/src/main/java/com/iluwatar/SimpleFileWriter.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="88" width="261" x="213" y="298"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </class>
+ <interface id="2" language="java" name="com.iluwatar.FileWriterAction" project="execute-around"
+ file="/execute-around/src/main/java/com/iluwatar/FileWriterAction.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="88" width="164" x="514" y="298"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </interface>
+ <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </classifier-display>
+ <association-display labels="true" multiplicity="true"/>
+</class-diagram>
\ No newline at end of file
diff --git a/execute-around/pom.xml b/execute-around/pom.xml
new file mode 100644
index 000000000..8d8862063
--- /dev/null
+++ b/execute-around/pom.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+ <modelVersion>4.0.0</modelVersion>
+ <parent>
+ <groupId>com.iluwatar</groupId>
+ <artifactId>java-design-patterns</artifactId>
+ <version>1.0-SNAPSHOT</version>
+ </parent>
+ <artifactId>execute-around</artifactId>
+ <dependencies>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ <scope>test</scope>
+ </dependency>
+ </dependencies>
+</project>
diff --git a/execute-around/src/main/java/com/iluwatar/App.java b/execute-around/src/main/java/com/iluwatar/App.java
new file mode 100644
index 000000000..d3db00045
--- /dev/null
+++ b/execute-around/src/main/java/com/iluwatar/App.java
@@ -0,0 +1,30 @@
+package com.iluwatar;
+
+import java.io.FileWriter;
+import java.io.IOException;
+
+/**
+ * The Execute Around idiom specifies some code to be executed before and after
+ * a method. Typically the idiom is used when the API has methods to be executed in
+ * pairs, such as resource allocation/deallocation or lock acquisition/release.
+ *
+ * In this example, we have SimpleFileWriter class that opens and closes the file
+ * for the user. The user specifies only what to do with the file by providing the
+ * FileWriterAction implementation.
+ *
+ */
+public class App {
+
+ public static void main( String[] args ) throws IOException {
+
+ new SimpleFileWriter("testfile.txt", new FileWriterAction() {
+
+ @Override
+ public void writeFile(FileWriter writer) throws IOException {
+ writer.write("Hello");
+ writer.append(" ");
+ writer.append("there!");
+ }
+ });
+ }
+}
diff --git a/execute-around/src/main/java/com/iluwatar/FileWriterAction.java b/execute-around/src/main/java/com/iluwatar/FileWriterAction.java
new file mode 100644
index 000000000..3f4fcd16c
--- /dev/null
+++ b/execute-around/src/main/java/com/iluwatar/FileWriterAction.java
@@ -0,0 +1,15 @@
+package com.iluwatar;
+
+import java.io.FileWriter;
+import java.io.IOException;
+
+/**
+ *
+ * Interface for specifying what to do with the file resource.
+ *
+ */
+public interface FileWriterAction {
+
+ void writeFile(FileWriter writer) throws IOException;
+
+}
diff --git a/execute-around/src/main/java/com/iluwatar/SimpleFileWriter.java b/execute-around/src/main/java/com/iluwatar/SimpleFileWriter.java
new file mode 100644
index 000000000..c4be8a9fa
--- /dev/null
+++ b/execute-around/src/main/java/com/iluwatar/SimpleFileWriter.java
@@ -0,0 +1,23 @@
+package com.iluwatar;
+
+import java.io.FileWriter;
+import java.io.IOException;
+
+/**
+ *
+ * SimpleFileWriter handles opening and closing file for the user. The user
+ * only has to specify what to do with the file resource through FileWriterAction
+ * parameter.
+ *
+ */
+public class SimpleFileWriter {
+
+ public SimpleFileWriter(String filename, FileWriterAction action) throws IOException {
+ FileWriter writer = new FileWriter(filename);
+ try {
+ action.writeFile(writer);
+ } finally {
+ writer.close();
+ }
+ }
+}
diff --git a/execute-around/src/test/java/com/iluwatar/AppTest.java b/execute-around/src/test/java/com/iluwatar/AppTest.java
new file mode 100644
index 000000000..3f256e7aa
--- /dev/null
+++ b/execute-around/src/test/java/com/iluwatar/AppTest.java
@@ -0,0 +1,19 @@
+package com.iluwatar;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+/**
+ *
+ * Tests execute-around example.
+ *
+ */
+public class AppTest {
+
+ @Test
+ public void test() throws IOException {
+ String[] args = {};
+ App.main(args);
+ }
+}
diff --git a/pom.xml b/pom.xml
index 80f25c549..58cf19777 100644
--- a/pom.xml
+++ b/pom.xml
@@ -41,8 +41,14 @@
<module>null-object</module>
<module>event-aggregator</module>
<module>callback</module>
+<<<<<<< HEAD
<module>intercepting-filter</module>
</modules>
+=======
+ <module>execute-around</module>
+ <module>property</module>
+ </modules>
+>>>>>>> origin/master
<dependencyManagement>
<dependencies>
diff --git a/property/etc/property.jpg b/property/etc/property.jpg
new file mode 100644
index 000000000..e3da03e0c
Binary files /dev/null and b/property/etc/property.jpg differ
diff --git a/property/etc/property.ucls b/property/etc/property.ucls
new file mode 100644
index 000000000..0ad1d61eb
--- /dev/null
+++ b/property/etc/property.ucls
@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.8" icons="true" automaticImage="JPEG" always-add-relationships="false"
+ generalizations="true" realizations="true" associations="true" dependencies="false" nesting-relationships="true">
+ <class id="1" language="java" name="com.iluwatar.Character" project="property"
+ file="/property/src/main/java/com/iluwatar/Character.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="-1" width="-1" x="497" y="232"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </class>
+ <enumeration id="2" language="java" name="com.iluwatar.Character.Type" project="property"
+ file="/property/src/main/java/com/iluwatar/Character.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="-1" width="-1" x="320" y="231"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </enumeration>
+ <enumeration id="3" language="java" name="com.iluwatar.Stats" project="property"
+ file="/property/src/main/java/com/iluwatar/Stats.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="-1" width="-1" x="695" y="205"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </enumeration>
+ <interface id="4" language="java" name="com.iluwatar.Prototype" project="property"
+ file="/property/src/main/java/com/iluwatar/Prototype.java" binary="false" corner="BOTTOM_RIGHT">
+ <position height="-1" width="-1" x="495" y="487"/>
+ <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </display>
+ </interface>
+ <association id="5">
+ <end type="SOURCE" refId="1" navigable="false">
+ <attribute id="6" name="type"/>
+ <multiplicity id="7" minimum="0" maximum="1"/>
+ </end>
+ <end type="TARGET" refId="2" navigable="true"/>
+ <display labels="true" multiplicity="true"/>
+ </association>
+ <association id="8">
+ <end type="SOURCE" refId="1" navigable="false">
+ <attribute id="9" name="prototype"/>
+ <multiplicity id="10" minimum="0" maximum="1"/>
+ </end>
+ <end type="TARGET" refId="4" navigable="true"/>
+ <display labels="true" multiplicity="true"/>
+ </association>
+ <nesting id="11">
+ <end type="SOURCE" refId="1"/>
+ <end type="TARGET" refId="2"/>
+ </nesting>
+ <realization id="12">
+ <end type="SOURCE" refId="1"/>
+ <end type="TARGET" refId="4"/>
+ </realization>
+ <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true"
+ sort-features="false" accessors="true" visibility="true">
+ <attributes public="true" package="true" protected="true" private="true" static="true"/>
+ <operations public="true" package="true" protected="true" private="true" static="true"/>
+ </classifier-display>
+ <association-display labels="true" multiplicity="true"/>
+</class-diagram>
\ No newline at end of file
diff --git a/property/pom.xml b/property/pom.xml
new file mode 100644
index 000000000..a26894f0a
--- /dev/null
+++ b/property/pom.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+ <modelVersion>4.0.0</modelVersion>
+ <parent>
+ <groupId>com.iluwatar</groupId>
+ <artifactId>java-design-patterns</artifactId>
+ <version>1.0-SNAPSHOT</version>
+ </parent>
+ <artifactId>property</artifactId>
+ <dependencies>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ <scope>test</scope>
+ </dependency>
+ </dependencies>
+</project>
diff --git a/property/src/main/java/com/iluwatar/App.java b/property/src/main/java/com/iluwatar/App.java
new file mode 100644
index 000000000..95ff4355f
--- /dev/null
+++ b/property/src/main/java/com/iluwatar/App.java
@@ -0,0 +1,49 @@
+package com.iluwatar;
+
+import com.iluwatar.Character.Type;
+
+/**
+ * Example of Character instantiation using Property pattern (as concept also known like Prototype inheritance).
+ * In prototype inheritance instead of classes, as opposite to Java class inheritance,
+ * objects are used to create another objects and object hierarchies.
+ * Hierarchies are created using prototype chain through delegation: every object has link to parent object.
+ * Any base (parent) object can be amended at runtime (by adding or removal of some property), and all child objects will be affected as result.
+ */
+public class App {
+
+ public static void main(String[] args) {
+ /* set up */
+ Prototype charProto = new Character();
+ charProto.set(Stats.STRENGTH, 10);
+ charProto.set(Stats.AGILITY, 10);
+ charProto.set(Stats.ARMOR, 10);
+ charProto.set(Stats.ATTACK_POWER, 10);
+
+ Character mageProto = new Character(Type.MAGE, charProto);
+ mageProto.set(Stats.INTELLECT, 15);
+ mageProto.set(Stats.SPIRIT, 10);
+
+ Character warProto = new Character(Type.WARRIOR, charProto);
+ warProto.set(Stats.RAGE, 15);
+ warProto.set(Stats.ARMOR, 15); // boost default armor for warrior
+
+ Character rogueProto = new Character(Type.ROGUE, charProto);
+ rogueProto.set(Stats.ENERGY, 15);
+ rogueProto.set(Stats.AGILITY, 15); // boost default agility for rogue
+
+ /* usage */
+ Character mag = new Character("Player_1", mageProto);
+ mag.set(Stats.ARMOR, 8);
+ System.out.println(mag);
+
+ Character warrior = new Character("Player_2", warProto);
+ System.out.println(warrior);
+
+ Character rogue = new Character("Player_3", rogueProto);
+ System.out.println(rogue);
+
+ Character rogueDouble = new Character("Player_4", rogue);
+ rogueDouble.set(Stats.ATTACK_POWER, 12);
+ System.out.println(rogueDouble);
+ }
+}
diff --git a/property/src/main/java/com/iluwatar/Character.java b/property/src/main/java/com/iluwatar/Character.java
new file mode 100644
index 000000000..ac8abaa0e
--- /dev/null
+++ b/property/src/main/java/com/iluwatar/Character.java
@@ -0,0 +1,117 @@
+package com.iluwatar;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Represents Character in game and his abilities (base stats).
+ */
+public class Character implements Prototype {
+
+ public enum Type {
+ WARRIOR, MAGE, ROGUE
+ }
+
+ private final Prototype prototype;
+ private final Map<Stats, Integer> properties = new HashMap<>();
+
+ private String name;
+ private Type type;
+
+ public Character() {
+ this.prototype = new Prototype() { // Null-value object
+ @Override
+ public Integer get(Stats stat) {
+ return null;
+ }
+ @Override
+ public boolean has(Stats stat) {
+ return false;
+ }
+ @Override
+ public void set(Stats stat, Integer val) {
+ }
+ @Override
+ public void remove(Stats stat) {
+ }}
+ ;
+ }
+
+ public Character(Type type, Prototype prototype) {
+ this.type = type;
+ this.prototype = prototype;
+ }
+
+ public Character(String name, Character prototype) {
+ this.name = name;
+ this.type = prototype.type;
+ this.prototype = prototype;
+ }
+
+ public String name() {
+ return name;
+ }
+
+ public Type type() {
+ return type;
+ }
+
+ @Override
+ public Integer get(Stats stat) {
+ boolean containsValue = properties.containsKey(stat);
+ if (containsValue) {
+ return properties.get(stat);
+ } else {
+ return prototype.get(stat);
+ }
+ }
+
+ @Override
+ public boolean has(Stats stat) {
+ return get(stat) != null;
+ }
+
+ @Override
+ public void set(Stats stat, Integer val) {
+ properties.put(stat, val);
+ }
+
+ @Override
+ public void remove(Stats stat) {
+ properties.put(stat, null);
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder builder = new StringBuilder();
+ if (name != null) {
+ builder
+ .append("Player: ")
+ .append(name)
+ .append("\n");
+ }
+
+ if (type != null) {
+ builder
+ .append("Character type: ")
+ .append(type.name())
+ .append("\n");
+ }
+
+ builder.append("Stats:\n");
+ for (Stats stat : Stats.values()) {
+ Integer value = this.get(stat);
+ if (value == null) {
+ continue;
+ }
+ builder
+ .append(" - ")
+ .append(stat.name())
+ .append(":")
+ .append(value)
+ .append("\n");
+ }
+ return builder.toString();
+ }
+
+}
diff --git a/property/src/main/java/com/iluwatar/Prototype.java b/property/src/main/java/com/iluwatar/Prototype.java
new file mode 100644
index 000000000..ef9d2d7b6
--- /dev/null
+++ b/property/src/main/java/com/iluwatar/Prototype.java
@@ -0,0 +1,12 @@
+package com.iluwatar;
+
+/**
+ * Interface for prototype inheritance
+ */
+public interface Prototype {
+
+ public Integer get(Stats stat);
+ public boolean has(Stats stat);
+ public void set(Stats stat, Integer val);
+ public void remove(Stats stat);
+}
diff --git a/property/src/main/java/com/iluwatar/Stats.java b/property/src/main/java/com/iluwatar/Stats.java
new file mode 100644
index 000000000..3c5648148
--- /dev/null
+++ b/property/src/main/java/com/iluwatar/Stats.java
@@ -0,0 +1,9 @@
+package com.iluwatar;
+
+/**
+ * All possible attributes that Character can have
+ */
+public enum Stats {
+
+ AGILITY, STRENGTH, ATTACK_POWER, ARMOR, INTELLECT, SPIRIT, ENERGY, RAGE
+}
diff --git a/property/src/test/java/com/iluwatar/AppTest.java b/property/src/test/java/com/iluwatar/AppTest.java
new file mode 100644
index 000000000..6db5ad214
--- /dev/null
+++ b/property/src/test/java/com/iluwatar/AppTest.java
@@ -0,0 +1,12 @@
+package com.iluwatar;
+
+import org.junit.Test;
+
+public class AppTest {
+
+ @Test
+ public void test() {
+ String[] args = {};
+ App.main(args);
+ }
+}