Bridge design pattern

README.md

@@ -1,2 +1,31 @@
-# DesignPatternsJava9
-This repo consists Gang of Four Design patterns code on Java 9. Each branch in the repository has code of 1 design pattern. Switch repository to try out different design patterns.
+# What is Bridge Design Pattern 
+* The bridge pattern can also be thought of as two layers of abstraction.
+* Bridge pattern Decouples an abstraction so two classes can vary independently.
+
+## Diagram
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/bridge-pattern/diagrams/Bridge%20Design%20Pattern%20class%20diagram.png "Diagram")
+
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/bridge-pattern/diagrams/4_4_Bridge_pattern_sequence.png "Diagram")
+
+### When to use Bridge Design Pattern 
+When we need to make functionality of concrete classes independent from interface implementer classes. Both types of classes can be altered structurally without affecting each other.
+
+### Learn Design Patterns with Java by Aseem Jain
+This repository contains working project code used in video Course by Packt Publication with title "Learn Design Patterns with Java " authored by "Aseem Jain".
+
+### Course link: 
+https://www.packtpub.com/application-development/learn-design-patterns-java-9-video
+
+### ![ http://in.linkedin.com/in/premaseem](https://github.com/premaseem/DesignPatternsJava9/blob/master/linkedin.png "http://in.linkedin.com/in/premaseem") Profile:  http://in.linkedin.com/in/premaseem
+
+### Authors blog on design patterns:
+https://premaseem.wordpress.com/category/computers/design-patterns/
+
+### Software Design pattern community face book page:
+https://www.facebook.com/DesignPatternGuru/
+
+### Note: 
+* This code base will work on Java 9 and above versions. 
+* `diagrams` folders carry UML diagrams.
+* `pattern` folder has code of primary example. 
+* `patternBonus` folder has code of secondary or bonus example.

pattern/src/com/premaseem/BridgeRemoteControl.java

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+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+public abstract class BridgeRemoteControl {
+
+    // Introduced has a relationship
+    private ITV tv;
+
+    public BridgeRemoteControl (ITV tv) {
+        this.tv = tv;
+    }
+
+    public void turnOn () {
+        tv.on();
+    }
+
+    public void turnOff () {
+        tv.off();
+    }
+
+    public void setChannel (int channel) {
+        tv.switchProgram(channel);
+    }
+
+    // additional features
+    public void recordProgram(){
+        System.out.println("IndependentRemoteControl use keyword to set channel.");
+    }
+}
+
+
+class IndependentRemoteControl extends BridgeRemoteControl {
+    public IndependentRemoteControl (ITV tv) {
+        super(tv);
+    }
+
+    public void setChannelKeyboard (int channel) {
+        setChannel(channel);
+        System.out.println("IndependentRemoteControl use keyword to set channel.");
+    }
+
+
+}
+
+// coupled implementation of remote controller
+class DependentRemoteControl implements ITV {
+    @Override
+    public void on () {
+        System.out.println(" Forced to change, if TV interface changes ");
+    }
+
+    @Override
+    public void off () {
+        System.out.println(" Forced to change, if TV interface changes ");
+    }
+
+    @Override
+    public void switchProgram (int channel) {
+        System.out.println(" Forced to change, if TV interface changes ");
+    }
+
+}

pattern/src/com/premaseem/Client.java

@@ -4,10 +4,28 @@
 @author: Aseem Jain
 @title: Design Patterns with Java 9
 @link: https://premaseem.wordpress.com/category/computers/design-patterns/
-@copyright: 2018 Packt Publication
 */
 public class Client {
     public static void main (String[] args) {
-        System.out.println("Singleton cook example ");
+        System.out.println("Bridge design pattern example ");
+        ITV tv = new SonyTV();
+
+        // Bridge between Remote and TV interface helps both of them to
+        // evolve independently
+        IndependentRemoteControl remote = new IndependentRemoteControl(tv);
+        remote.turnOn();
+        remote.setChannel(7);
+        remote.turnOff();
+        // additional methods
+        remote.recordProgram();
+
+
+/*
+//        // DependentRemoteControl sub classes TV interface
+//        // and is forced to change even with minor changes in TV interface
+//        DependentRemoteControl remote = new DependentRemoteControl();
+//        remote.on();
+//        remote.switchProgram(23);
+ */
     }
 }

pattern/src/com/premaseem/ITV.java

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+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+
+public interface ITV {
+    public void on ();
+
+    public void off ();
+
+    public void switchProgram (int channel);
+}
+
+class SamsungTV implements ITV {
+    @Override
+    public void on () {
+        System.out.println("Samsung is turned on.");
+    }
+
+    @Override
+    public void off () {
+        System.out.println("Samsung is turned off.");
+    }
+
+    @Override
+    public void switchProgram (int channel) {
+        System.out.println("Samsung: channel - " + channel);
+    }
+}
+
+class SonyTV implements ITV {
+
+    @Override
+    public void on () {
+        System.out.println("Sony is turned on.");
+    }
+
+    @Override
+    public void off () {
+        System.out.println("Sony is turned off.");
+    }
+
+    @Override
+    public void switchProgram (int channel) {
+        System.out.println("Sony: channel - " + channel);
+    }
+}