實例解析Java設計模式編程中的適配器模式使用

public class DrawRectangle {//畫方 
 public void drawRectangle(String msg) { 
  System.out.println("draw Rectangle: " + msg); 
 } 
} 
public interface IDrawCircle {//畫圓的接口 
 void drawCircle(); 
} 
/** 
 * 類適配器 使用對象繼承的方式，是靜態(tài)的定義方式 
 * @author stone 
 * 
 */
public class DrawAdapter4Class extends DrawRectangle implements IDrawCircle {//既能畫方又能畫圓 
 @Override
 public void drawCircle() { 
  System.out.println("DrawAdapter4Class: drawCircle"); 
 }   
}

/** 
 * 對象適配器： 使用對象組合的方式，是動態(tài)組合的方式。 
 * 既能畫方又能畫圓 
 * @author stone 
 * DrawAdapter是適配器，DrawRectangle屬于adapter,是被適配者，適配器將被適配者和適配目標（DrawCircle）進行適配 
 * 
 */
public class DrawAdapter4Object implements IDrawCircle {//既能畫方又能畫圓  
 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); 
 }   
} 

/* 
 * 接口適配器:接口中有抽象方法，我們只想實現(xiàn)其中的幾個，不想全部實現(xiàn)， 
 * 所以提供一個默認空實現(xiàn)，然后繼承自它，重寫實現(xiàn)我們想實現(xiàn)的方法 
 */
public interface IDraw { 
 void drawCircle(); 
 void drawRectangle(); 
} 
/* 
 * 接口適配器 的默認實現(xiàn) 
 */
public class DefaultDrawAdapter implements IDraw {//畫方 畫圓 皆為空實現(xiàn) 
 @Override
 public void drawCircle() { 
 } 
 @Override
 public void drawRectangle() { 
public class Test { 
 public static void main(String[] args) { 
  //對象適配器 
  DrawAdapter4Object objAdapter = new DrawAdapter4Object(new DrawRectangle()); 
  objAdapter.drawCircle(); 
  objAdapter.drawRectangle(" in DrawAdapter4Object"); 
  System.out.println("--------------");    
  //類適配器 
  DrawAdapter4Class clzAdapter = new DrawAdapter4Class(); 
  clzAdapter.drawCircle(); 
  clzAdapter.drawRectangle("in DrawAdapter4Class");  
  System.out.println("--------------"); 
  //接口適配器 
  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