Java Tutorial/Design Pattern/Bridge Pattern

A demonstration of the structure and operation of the Bridge Pattern.

   <source lang="java">

class Abstraction {

 private Task task;
 public Abstraction(Task imp) {
   task = imp;
 }
 public void service1() {
   task.task1();
   task.task2();
 }
 public void service2() {
   task.task2();
   task.task3();
 }
 public void service3() {
   task.task1();
   task.task2();
   task.task4();
 }
 protected Task getImplementation() {
   return task;
 }

} class ClientService1 extends Abstraction {

 public ClientService1(Task imp) {
   super(imp);
 }
 public void serviceA() {
   service1();
   service2();
 }
 public void serviceB() {
   service3();
 }

} class ClientService2 extends Abstraction {

 public ClientService2(Task imp) {
   super(imp);
 }
 public void serviceC() {
   service2();
   service3();
 }
 public void serviceD() {
   service1();
   service3();
 }
 public void serviceE() {
   getImplementation().task3();
 }

} interface Task {

 void task1();
 void task2();
 void task3();
 void task4();

} class Integration1 {

 public void method1() {
   System.out.println("Integration1.method1()");
 }
 public void method2() {
   System.out.println("Integration1.method2()");
 }

} class Integration {

 public void operation1() {
   System.out.println("Integration.operation1()");
 }
 public void operation2() {
   System.out.println("Integration.operation2()");
 }
 public void operation3() {
   System.out.println("Integration.operation3()");
 }

} class Implementation1 implements Task {

 private Integration1 delegate = new Integration1();
 public void task1() {
   System.out.println("Implementation1.facility1");
   delegate.method1();
 }
 public void task2() {
   System.out.println("Implementation1.facility2");
   delegate.method2();
 }
 public void task3() {
   System.out.println("Implementation1.facility3");
   delegate.method2();
   delegate.method1();
 }
 public void task4() {
   System.out.println("Implementation1.facility4");
   delegate.method1();
 }

} class Implementation2 implements Task {

 private Integration delegate = new Integration();
 public void task1() {
   System.out.println("Implementation2.facility1");
   delegate.operation1();
 }
 public void task2() {
   System.out.println("Implementation2.facility2");
   delegate.operation2();
 }
 public void task3() {
   System.out.println("Implementation2.facility3");
   delegate.operation3();
 }
 public void task4() {
   System.out.println("Implementation2.facility4");
   delegate.operation1();
 }

} public class BridgeStructure {

 public static void main(String[] args) {
   ClientService1 cs1 = new ClientService1(new Implementation1());
   cs1.serviceA();
   cs1.serviceB();
   cs1 = new ClientService1(new Implementation2());
   cs1.serviceA();
   cs1.serviceB();
   ClientService2 cs2 = new ClientService2(new Implementation1());
   cs2.serviceC();
   cs2.serviceD();
   cs2.serviceE();
   cs2 = new ClientService2(new Implementation2());
   cs2.serviceC();
   cs2.serviceD();
   cs2.serviceE();
 }

}</source>