JAVA设计模式(15)行为型-状态模式

允许一个对象在其内部状态改变时改变它的行为，对象看起来似乎修改了它的类。

//@author v: jbossjf
package com.roc.state;

public class Context {

    private State state;
    
    public Context(State state){
        this.state=state;
    }

    public State getState() {
        return state;
    }

    public void setState(State state) {
        this.state = state;
    }
    
    public void stateChange(){
        state.action(this);
    }
    
}

package com.roc.state;

public abstract class State {
    public abstract void action(Context context);
}

package com.roc.state;

public class OpenSate extends State{

    public void action(Context context) {
        System.out.println("开");
        context.setState(new CloseState());
    }

}

package com.roc.state;

public class CloseState extends State{

    public void action(Context context) {
        System.out.println("关");
        context.setState(new OpenSate());
    }

}

package com.roc.state;

public class Client {
    public static void main(String[] args) {
        Context context=new Context(new CloseState());
        context.stateChange();
        context.stateChange();
        context.stateChange();
        context.stateChange();
        context.stateChange();
        context.stateChange();
        context.stateChange();
        context.stateChange();
    }
}