设计模式_装饰模式概述和使用

装饰设计模式概述装饰模式就是使用被装饰类的一个子类的实例，在客户端将这个子类的实例交给装饰类。是继承的替代方案优点使用装饰模式，可以提供比继承更灵活的扩展对象的功能，它可以动态的添加对象的功能，并且可以随意的组合这些功能缺点正因为可以随意组合，所以就可能出现一些不合理的逻辑

package cn.itcast_02;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.util.Scanner;public class PhoneDemo {public static void main(String[] args) {Phone p = new IPhone();p.call();System.out.println("------------");// 需求:我想在接电话前,听彩铃PhoneDecorate pd = new RingPhoneDecorate(p);pd.call();System.out.println("------------");// 需求:我想在接电话后,听音乐pd = new MusicPhoneDecorate(p);pd.call();System.out.println("------------");System.out.println("------------");// 需求:我要想手机在接前听彩铃,接后听音乐pd = new RingPhoneDecorate(new MusicPhoneDecorate(p));pd.call();System.out.println("------------");// 想想我们在IO流中的使用// InputStream is = System.in;// InputStreamReader isr = new InputStreamReader(is);// BufferedReader br = new BufferedReader(isr);BufferedReader br = new BufferedReader(new InputStreamReader(System.in));BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));Scanner sc = new Scanner(System.in);}}

package cn.itcast_02;public interface Phone {public abstract void call();}

package cn.itcast_02;public class IPhone implements Phone {@Overridepublic void call() {System.out.println("手机可以打电话了");}}

package cn.itcast_02;public abstract class PhoneDecorate implements Phone {public Phone p;public PhoneDecorate(Phone p) {this.p = p;}@Overridepublic void call() {this.p.call();}}

package cn.itcast_02;public class MusicPhoneDecorate extends PhoneDecorate {public MusicPhoneDecorate(Phone p) {super(p);}@Overridepublic void call() {super.call();System.out.println("手机可以听音乐");}}

package cn.itcast_02;public class MusicPhoneDecorate extends PhoneDecorate {public MusicPhoneDecorate(Phone p) {super(p);}@Overridepublic void call() {super.call();System.out.println("手机可以听音乐");}}