实例解析Java设计模式编程中的适配器模式使用

public class DrawRectangle {//画方 
 public void drawRectangle(String msg) { 
  System.out.println("draw Rectangle: " + msg); 
 } 
} 
public interface IDrawCircle {//画圆的接口 
 void drawCircle(); 
} 
/** 
 * 类适配器 使用对象继承的方式，是静态的定义方式 
 * @author stone 
 * 
 */
public class DrawAdapter4Class extends DrawRectangle implements IDrawCircle {//既能画方又能画圆 
 @Override
 public void drawCircle() { 
  System.out.println("DrawAdapter4Class: drawCircle"); 
 }   
}

/** 
 * 对象适配器： 使用对象组合的方式，是动态组合的方式。 
 * 既能画方又能画圆 
 * @author stone 
 * DrawAdapter是适配器，DrawRectangle属于adapter,是被适配者，适配器将被适配者和适配目标（DrawCircle）进行适配 
 * 
 */
public class DrawAdapter4Object implements IDrawCircle {//既能画方又能画圆  
 private DrawRectangle drawRectangle; 
 public DrawAdapter4Object(DrawRectangle drawRectangle) { 
  this.drawRectangle = drawRectangle; 
 }  
 @Override
 public void drawCircle() { 
  System.out.println("DrawAdapter4Object: drawcircle"); 
 }   
 public void drawRectangle(String msg) { 
  drawRectangle.drawRectangle(msg); 
 }   
} 

/* 
 * 接口适配器:接口中有抽象方法，我们只想实现其中的几个，不想全部实现， 
 * 所以提供一个默认空实现，然后继承自它，重写实现我们想实现的方法 
 */
public interface IDraw { 
 void drawCircle(); 
 void drawRectangle(); 
} 
/* 
 * 接口适配器 的默认实现 
 */
public class DefaultDrawAdapter implements IDraw {//画方 画圆 皆为空实现 
 @Override
 public void drawCircle() { 
 } 
 @Override
 public void drawRectangle() { 
public class Test { 
 public static void main(String[] args) { 
  //对象适配器 
  DrawAdapter4Object objAdapter = new DrawAdapter4Object(new DrawRectangle()); 
  objAdapter.drawCircle(); 
  objAdapter.drawRectangle(" in DrawAdapter4Object"); 
  System.out.println("--------------");    
  //类适配器 
  DrawAdapter4Class clzAdapter = new DrawAdapter4Class(); 
  clzAdapter.drawCircle(); 
  clzAdapter.drawRectangle("in DrawAdapter4Class");  
  System.out.println("--------------"); 
  //接口适配器 
  MyDrawAdapter myDrawAdapter = new MyDrawAdapter(); 
  myDrawAdapter.drawCircle(); 
  myDrawAdapter.drawRectangle(); 
 } 
 static class MyDrawAdapter extends DefaultDrawAdapter { 
  @Override
  public void drawCircle() { 
   System.out.println("drawCircle in MyDrawAdapter"); 
  } 
   
 } 
}

DrawAdapter4Object: drawcircle 
draw Rectangle: in DrawAdapter4Object 
-------------- 
DrawAdapter4Class: drawCircle 
draw Rectangle: in DrawAdapter4Class 
-------------- 
drawCircle in MyDrawAdapter