状态模式

Posted on | In |

状态模式要达到的目的：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

具体实例


Application
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package zhuangtaimoshi;

/**
 * Created by 15581 on 2017/11/8.
 */ // Application.java
public class Application{
     public static void main(String args[]) {
           TemperatureState state=new LowState(-12);
           Thermometer  thermometer=new Thermometer();
           thermometer.setState(state);
           thermometer.showMessage();
           state=new MiddleState(20);
           thermometer.setState(state);
           thermometer.showMessage();
           state=new HeightState(39);
           thermometer.setState(state);
           thermometer.showMessage();
     }
}

HeightState

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package zhuangtaimoshi;

/**
 * Created by 15581 on 2017/11/8.
 */ // HeightState.java
public class HeightState implements TemperatureState{
       double n=26;
       HeightState(int n){
            if(n>26)
               this.n=n;
       }
       public void showTemperature(){
              System.out.println("现在温度是"+n+"属于高温度");
       }
}

LowState

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package zhuangtaimoshi;

/**
 * Created by 15581 on 2017/11/8.
 */ // LowState.java
public class LowState implements TemperatureState{
       double n=0;
       LowState(double n){
            if(n<=0)
              this.n=n;
       }
       public void showTemperature(){
              System.out.println("现在温度是"+n+"属于低温度");
       }
}

MiddleState

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package zhuangtaimoshi;

/**
 * Created by 15581 on 2017/11/8.
 */ // MiddleState.java
public class MiddleState implements TemperatureState{
       double n=10;
       MiddleState(int n){
            if(n>0&&n<=26)
               this.n=n;
       }
       public void showTemperature(){
              System.out.println("现在温度是"+n+"属于正常温度");
       }
}

TemperatureState

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package zhuangtaimoshi;

/**
 * Created by 15581 on 2017/11/8.
 */ // TemperatureState.java
public  interface  TemperatureState{
      public void showTemperature();
}

Thermometer

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package zhuangtaimoshi;

// Thermometer.java
public  class  Thermometer{
      TemperatureState  state;
       public  void  showMessage(){
            System.out.println("***********");
            state.showTemperature();  
            System.out.println("***********");
      }
      public void setState(TemperatureState  state){
            this.state=state;
      }
}