设计模式-装饰者模式

装饰者模式

/**
 * 被装饰抽象类
 */
public abstract class Component {

    //抽象方法
    public abstract void operate();
}


/**
 * 具体构件（被装饰者）
 */
public class ConcreteComponent extends Component {

    @Override
    public void operate() {
        System.out.println("do something");
    }
}

//装饰接口
public class Decorator extends Component{

    private Component component=null;

    //注入被装饰者
    public Decorator(Component component) {
        this.component = component;
    }

    //委托装饰者调用
    @Override
    public void operate() {
        this.component.operate();
    }
}

//装饰封装1
public class ConcreteDecorator1 extends Decorator{
    public ConcreteDecorator1(Component component) {
        super(component);
    }

    private void Method1(){
        System.out.println("我是修饰方法一");
    }

    @Override
    public void operate() {
        this.Method1();
        super.operate();
    }
}

//装饰封装2
public class ConcreteDecorator2 extends Decorator{
    public ConcreteDecorator2(Component component) {
        super(component);
    }

    private void Method2(){
        System.out.println("我是修饰方法二");
    }

    @Override
    public void operate() {
        this.Method2();
        super.operate();
    }
}

public class Test {
    public static void main(String[] args) {
        //被装饰者地址
        Component component = new ConcreteComponent();
        //被装饰者地址作为构造器字段传入实列化
       component= new ConcreteDecorator1(component);
       //已经被赋予构造器字段传入实例化有点类似链式结构ConcreteDecorator2(ConcreteDecorator1(ConcreteComponent))
       component= new ConcreteDecorator2(component);
       component.operate();
    }
}

结果：
我是修饰方法二
我是修饰方法一
do something