本篇随笔主要介绍用Java实现简单的装饰器设计模式：
先来看一下装饰器设计模式的类图：
从图中可以看到，我们可以装饰Component接口的任何实现类，而这些实现类也包括了装饰器本身，装饰器本身也可以再被装饰。
下面是用Java实现的简单的装饰器设计模式，提供的是从基本的加入咖啡入手，可以继续加入牛奶，巧克力，糖的装饰器系统。
interface Component {
void method();
}
class Coffee implements Component {
@Override
public void method() {
// TODO Auto-generated method stub
System.out.println("倒入咖啡");
}
}
class Decorator implements Component {
public Component comp;
public Decorator(Component comp) {
this.comp = comp;
}
@Override
public void method() {
// TODO Auto-generated method stub
comp.method();
}
}
class ConcreteDecorateA extends Decorator {
public Component comp;
public ConcreteDecorateA(Component comp) {
super(comp);
this.comp = comp;
}
public void method1() {
System.out.println("倒入牛奶");
}
public void method2() {
System.out.println("加入糖 ");
}
public void method() {
super.method();
method1();
method2();
}
}
class ConcreteDecorateB extends Decorator {
public Component comp;
public ConcreteDecorateB(Component comp) {
super(comp);
this.comp = comp;
}
public void method1() {
System.out.println("加入巧克力");
}
public void method() {
super.method();
method1();
}
}
public class TestDecoratePattern {
public static void main(String[] args) {
Component comp = new Coffee();
comp.method();
System.out.println("--------------------------------------------------");
Component comp1 = new ConcreteDecorateA(comp);
comp1.method();
System.out.println("--------------------------------------------------");
Component comp2 = new ConcreteDecorateB(comp1);
comp2.method();
System.out.println("--------------------------------------------------");
Component comp3 = new ConcreteDecorateB(new ConcreteDecorateA(new Coffee()));
comp3.method();
System.out.println("--------------------------------------------------");
Component comp4 = new ConcreteDecorateA(new ConcreteDecorateB(new Coffee()));
comp4.method();
}
}
运行结果：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
