一、概述
1.目標:要在Tank的move()方法做時間代理及日志代理(可以設想以后還要增加很多代理處理),且代理間的順序可活更換
2.思路:
(1)聚合:代理類聚合了被代理類,且代理類及被代理類都實現了movable接口,則可實現靈活多變,具體看代碼
(2)繼承:繼承不夠靈活,隨著功能需求增多,繼承體系會非常臃腫。具體看代碼
二、代碼
1.Movable.java
2.Tank.java
3.TankTimeProxy.java
4.TankLogProxy.java
5.Tank2Time.java
6.Tank3Log.java
7.Client.java
1.Movable.java
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public interface Movable { public void move(); } |
2.Tank.java
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import java.util.Random; public class Tank implements Movable { @Override public void move() { System.out.println( "Tank moving......." ); try { Thread.sleep( new Random().nextInt( 5000 )); } catch (InterruptedException e) { e.printStackTrace(); } } } |
3.TankTimeProxy.java
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public class TankTimeProxy implements Movable { Movable m; public TankTimeProxy(Movable m) { this .m = m; } @Override public void move() { System.out.println( "Time Proxy start..........." ); long start = System.currentTimeMillis(); m.move(); long end = System.currentTimeMillis(); System.out.println( "花費時間:" +(end - start)); System.out.println( "Time Proxy end..........." ); } } |
4.TankLogProxy.java
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public class TankLogProxy implements Movable { Movable m; public TankLogProxy(Movable m) { this .m = m; } @Override public void move() { System.out.println( "Log Proxy start..........." ); m.move(); System.out.println( "Log Proxy end..........." ); } } |
5.Tank2Time.java
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public class Tank2Time extends Tank { public void move(){ System.out.println( "Tank2 time start..........." ); long start = System.currentTimeMillis(); super .move(); long end = System.currentTimeMillis(); System.out.println( "花費時間:" +(end - start)); System.out.println( "Tank2 time end..........." ); } } |
6.Tank3Log.java
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public class Tank3Log extends Tank2Time { public void move(){ System.out.println( "Tank3Log start..........." ); super .move(); System.out.println( "Tank3Log end..........." ); } } |
7.Client.java
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public class Client { @Test public void testProxy(){ Tank t = new Tank(); Movable m; //一、聚合的方式(較靈活,因為實現了接口) //1.1聚合方式的代理,先日志代理,后時間代理 TankTimeProxy ttp1 = new TankTimeProxy(t); TankLogProxy tlp1 = new TankLogProxy(ttp1); m = tlp1; m.move(); System.out.println( "\n==============================分隔線==========================\n" ); //1.2聚合方式的代理,先時間代理,后日志代理(可以靈活切換順序) TankLogProxy tlp2 = new TankLogProxy(t); TankTimeProxy ttp2 = new TankTimeProxy(tlp2); m = ttp2; m.move(); System.out.println( "\n==============================分隔線==========================\n" ); //二、繼承的方式 //2.1代理時間 Tank2Time t2 = new Tank2Time(); t2.move(); System.out.println( "\n==============================分隔線==========================\n" ); //2.2先代理日志,后時間,不能靈活切換 Tank3Log t3 = new Tank3Log(); t3.move(); } } |
三、運行結果
因為每個代理都實現了同一movable接口,代理和被代理對象之間都可以相互靈活轉換,以實現代理功能之間的靈活疊加組合。
以上這篇java設計模式—靜態代理模式(聚合與繼承方式對比)就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支持服務器之家。