State pattern (sencode day)

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当一个对象内在状态改变时运行其改变行为，这个对象看起来像改变了其类

state - 抽象状态角色

接口或抽象类，负责对象状态定义，并且封装环境角色以实现状态切换。

concresteState - 具体状态角色

每一个具体状态必须完成两个职责：本状态的行为管理以趋向状态处理

context 环境角色
客户端需要的端口并且付诸具体状态的切换
状态模式相对来说比较复杂，它提供了一种物质运动的另一个观察视角，通过状态变更促使行为的变化

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

public abstract class LiftState {protected Context context;public Context getContext() {return context;}public void setContext(Context context) {this.context = context;}public abstract void open();public abstract void close();public abstract void run();public abstract void stop();}

public class Context {public final static OpenState openState = new OpenState();public final static CloseState closeState = new CloseState();public final static RunningState runningState = new RunningState();public final static StoppingState stopping = new StoppingState();private LiftState liftState;public LiftState getLiftState() {return liftState;}public void setLiftState(LiftState liftState) {this.liftState = liftState;this.liftState.setContext(this);}public void open(){this.liftState.open();}public void close(){this.liftState.close();}public void run(){this.liftState.run();}public void stop(){this.liftState.stop();}}

public class CloseState extends LiftState{@Overridepublic void close() { System.out.println("关闭");}@Overridepublic void open() {super.context.setLiftState(Context.openState);super.context.getLiftState().open();}@Overridepublic void run() {super.context.setLiftState(Context.runningState);super.context.getLiftState().run();}@Overridepublic void stop() {super.context.setLiftState(Context.stopping);super.context.getLiftState().stop();}}

public class OpenState extends LiftState{@Overridepublic void close() {super.context.setLiftState(Context.closeState);super.context.getLiftState().close(); }@Overridepublic void open() {System.out.println("打开");}@Overridepublic void run() { }@Overridepublic void stop() {// TODO Auto-generated method stub}}

public class RunningState extends LiftState {@Overridepublic void close() {}@Overridepublic void open() { }@Overridepublic void run() {System.out.println("正在运行");}@Overridepublic void stop() {super.context.setLiftState(Context.stopping);super.context.getLiftState().stop();}}

public class StoppingState extends LiftState {@Overridepublic void close() {}@Overridepublic void open() {super.context.setLiftState(Context.openState);super.context.getLiftState().open();}@Overridepublic void run() {super.context.setLiftState(Context.runningState);super.context.getLiftState().run();}@Overridepublic void stop() {System.out.println("停止运行...");}}

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