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例子：一个可以给人搭配不同服饰的系统，即可以换各种各样的衣服裤子的个人形象系统

最先想到的是，先建一个Person类

package deractor;public class Person {	private String name;	public Person(String name){		this.name=name;	}	public void show(){		System.out.println("装扮"+name);	}}

各种服饰的抽象类

package deractor;abstract class Finery {	public abstract void Show();}

服饰子类

package deractor;public class TShirts extends Finery{	@Override	public void Show() {		// TODO Auto-generated method stub		System.out.println("大T恤");	}}

package deractor;public class BigTrouser extends Finery{	@Override	public void Show() {		// TODO Auto-generated method stub		System.out.println("垮裤");	}}

package deractor;public class WearSneakers extends Finery{	@Override	public void Show() {		// TODO Auto-generated method stub		System.out.println("破球鞋");	}}

package deractor;public class WearSuit extends Finery{	@Override	public void Show() {		// TODO Auto-generated method stub		System.out.println("西装");	}	}

测试代码

package deractor;public class Test {	public static void main(String[] args) {		// TODO Auto-generated method stub		Person test=new Person("Autumn");		System.out.println("装扮如下");		Finery ts=new TShirts();		Finery bt=new BigTrouser();		Finery ws=new WearSneakers();		Finery wsuit=new WearSuit();		ts.Show();		bt.Show();		ws.Show();		wsuit.Show();	}}

Test中，把“大T恤”、“垮裤”、“破球鞋”、“西装”一个一个进行显示，好比：你光着身子，当着大家的面，一件一件穿上衣服，so，应该在内部组装完毕

即装饰模式Decorator，动态地给一个对象添加一些额外的职责，就增加功能来说，装饰模式比生成子类更为灵活。

其中，Component定义一个对象接口，可以给这些对象动态地添加职责。ConcreteComponent定义了一个具体的对象，也可以给这个对象添加一些职责。Decorator装饰抽象类，继承了Component，从外类来扩展Component类的功能，但对于Component来说，无需知道Decorator的存在，至于ConcreteDecorator就是具体的装饰对象，起到给Component添加职责的功能。基本代码实现如下：

package deractor;abstract class Component {	public abstract void Operation();}

package deractor;public class ConcreteComponent extends Component{	@Override	public void Operation() {		// TODO Auto-generated method stub		System.out.println("具体的操作对象");	}}

package deractor;abstract class Decorator extends Component{	protected Component component;	public void setComponent(Component component){		this.component=component;	}//	重写Operation，实际执行的是Component的Operation	public void Operation(){		if(component!=null){			component.Operation();		}	}}

package deractor;public class ConcreteDecoratorA extends Decorator{	private String addedState;	public void Operation(){		super.Operation();//首先运行原Operation，再执行本类的功能，如addedState，相当于对原Component进行了装饰		addedState="new state";		System.out.println("具体装饰对象A的操作");	}}

package deractor;public class ConcreteDecoratorB extends Decorator{	public void Operation(){		super.Operation();		AddedBehavior();		System.out.println("具体装饰对象B的操作");	}	private void AddedBehavior(){			}}

装饰的方法是：先用ConcreteComponent实例化对象c，然后用ConcreteDecoratorA的实例化对象d1来包装c，再用ConcreteDecoratorB的对象d2包装d1，最终执行d2的Operation

package deractor;public class DeTest {	public static void main(String[] args) {		// TODO Auto-generated method stub		ConcreteComponent c=new ConcreteComponent();		ConcreteDecoratorA d1=new ConcreteDecoratorA();		ConcreteDecoratorB d2=new ConcreteDecoratorB();				d1.setComponent(c);		d2.setComponent(d1);		d2.Operation();	}}

如果只有一个ConcreteComponent类而没有抽象的Component类，那么Decorator类可以是ConcreteComponent的一个子类，如果只有一个ConcreteDecorator类，那么就没有必要建立一个单独的Decorator类，而是可以把Decorator和ConcreteDecorator的责任合并成一个类

将上述衣服搭配稍作修改

package deractor;public class PersonConcreteComponent {	private String name;	public PersonConcreteComponent(){}	public PersonConcreteComponent(String name){		this.name=name;	}	public void Show(){		System.out.println("装扮的"+name);	}}

package deractor;public class FineryDecorator extends PersonConcreteComponent{	protected PersonConcreteComponent component;		public void Decorate(PersonConcreteComponent component){		this.component=component;	}	public void Show(){		if(component!=null){			component.Show();		}	}}

package deractor;public class TShirts2 extends FineryDecorator{	@Override	public void Show() {		// TODO Auto-generated method stub			super.Show();		System.out.println("大T恤");	}}

package deractor;public class WearSneakers2 extends FineryDecorator{	@Override	public void Show() {		// TODO Auto-generated method stub		super.Show();		System.out.println("破球鞋");	}}

package deractor;public class BigTrouser2 extends FineryDecorator{	@Override	public void Show() {		// TODO Auto-generated method stub		super.Show();		System.out.println("垮裤");	}}

package deractor;public class DecorateTest {	public static void main(String[] args) {		// TODO Auto-generated method stub		PersonConcreteComponent person=new PersonConcreteComponent("Autumn");		System.out.println("the following装扮");				TShirts2 ts=new TShirts2();		BigTrouser2 bt=new BigTrouser2();		WearSneakers2 ws=new WearSneakers2();				ts.Decorate(person);		bt.Decorate(ts);		ws.Decorate(bt);        ws.Show();	}}

运行结果：

the following装扮装扮的Autumn大T恤垮裤破球鞋

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