1.装饰器模式的定义（保持接口，扩展功能）
Decorate装饰器，顾名思义，就是动态的给一个对象添加一些额外的职责，就好比对房子进行装修一样。
2.装饰器模式的特征
具有一个装饰对象。
必须拥有与被装饰对象相同的接口。
可与给被装饰对象添加额外的功能。
3.装饰器模式的典型应用，java.io包
4.装饰器模式的代码示例
/** * @Author long * @Date 2019/3/20 21:29 */ public interface SourceAble { void operation(); }
/** * @Author long * @Date 2019/3/20 21:31 */ public class Source implements SourceAble { @Override public void operation() { System.out.println("Source最原始的方法"); } }
/** * @Author long * @Date 2019/3/20 21:32 */ public class SourceDecorateA implements SourceAble { private SourceAble sourceAble; public SourceDecorateA(SourceAble sourceAble){ this.sourceAble = sourceAble; } @Override public void operation() { System.out.println("SourceDecorateA before"); sourceAble.operation(); System.out.println("SourceDecorateA after"); } }
/** * @Author long * @Date 2019/3/20 21:34 */ public class SourceDecorateB implements SourceAble { private SourceAble sourceAble; public SourceDecorateB(SourceAble sourceAble){ this.sourceAble = sourceAble; } @Override public void operation() { System.out.println("SourceDecorateB before"); sourceAble.operation(); System.out.println("SourceDecorateB after"); } }
/** * @Author long * @Date 2019/3/20 21:48 */ public class App { public static void main(String[] args) { SourceAble source = new Source(); source.operation(); System.out.println("================"); SourceAble decorateA = new SourceDecorateA(source); decorateA.operation(); System.out.println("================"); SourceAble decorateB = new SourceDecorateB(decorateA); decorateB.operation(); } }
Source最原始的方法
================
SourceDecorateA before
Source最原始的方法
SourceDecorateA after
================
SourceDecorateB before
SourceDecorateA before
Source最原始的方法
SourceDecorateA after
SourceDecorateB after
原文：https://www.cnblogs.com/code-star/p/10567996.html