结构型模式之装饰模式

Myth丶恋晨 2022-08-10 03:55 151阅读 0赞

类图

![20151110114347165][]

package cn.装饰模式;
    
    public class Component {		//抽象构件
    	public void operation() {
    		System.out.println("抽象构件类operation()方法");
    	}
    }

package cn.装饰模式;
    
    public class ConcreteComponent extends Component{		//具体构件
    	public void operation() {
    		System.out.println("具体构件类的operation()方法");
    	}
    }

package cn.装饰模式;
    
    public class Decorator extends Component{		//抽象装饰类
    	private Component component;
    	public Decorator(Component component) {
    		this.component = component;
    	}		
    	
    	public void operation() {
    		component.operation();
    	}
    }

package cn.装饰模式;
    
    public class ConcreteDecoratorA extends Decorator{		//具体装饰类A
    	public ConcreteDecoratorA(Component component) {
    		super(component);
    	}
    	
    	public void operation() {
    		super.operation();
    		addedBehavior();
    	}
    	
    	public void addedBehavior() {
    		//新增方法
    		System.out.println("新增方法A");
    	}
    }

package cn.装饰模式;
    
    public class ConcreteDecoratorB extends Decorator{		//具体装饰类B
    	public ConcreteDecoratorB(Component component) {
    		super(component);
    	}
    	
    	public void operation() {
    		super.operation();
    		addedBehavior();
    	}
    	
    	public void addedBehavior() {
    		//新增方法
    		System.out.println("新增方法B");
    	}
    }

package cn.装饰模式;
    
    /*
     * 假如Component是变形金刚类，CocreteComponent是车类，ComcreteComponentA是机器人类，
     * ComcreteComponentB是飞机类。那么对象component是车，componentA是机器人，componentB
     * 是飞机，componentAB是机器人飞机，componentBA是飞机机器人。每个对象都是在车的基础上
     * 进行修饰的。这其实就是透明模式，只有当ComcreteComponentA和ComcreteComponentB中
     * 的operation()方法一致时才可以使用。否则就是半透明模式。
     */
    public class Client {		//客户端类
    	public static void main(String[] args) {
    		Component component, componentA,componentB,componentAB,componentBA;
    		component = new ConcreteComponent();		
    		component.operation();
    		System.out.println("-----------------------");
    		
    		componentA = new ConcreteDecoratorA(component);
    		componentA.operation();
    		System.out.println("-----------------------");
    		
    		componentB = new ConcreteDecoratorB(component);	
    		componentB.operation();
    		System.out.println("-----------------------");
    		
    		componentAB = new ConcreteDecoratorB(componentA);
    		componentAB.operation();
    		System.out.println("-----------------------");
    		
    		componentBA = new ConcreteDecoratorA(componentB);	
    		componentBA.operation();
    		System.out.println("-----------------------");
    	}
    }

运行效果图

![20151110114647595][]

[20151110114347165]: /images/20220731/a718069632d4492b8e1903a0b4162b4e.png
[20151110114647595]: /images/20220731/407feb75fef9444b84a3f773fb9ca6d4.png