Future 模式

future 模式类似于一张提货单。

future 意思就是未来、期货(金融领域)。

实际案例

类信息概览：

类名 说明
Main.java 方法的总入口
FutureData.java 未来的数据
Data.java 数据
Host.java 客户端
RealData.java 实际的数据

定义

  • FutureData.java
package com.github.houbb.thread.learn.easy.learn.future;

/**
 * 2018/2/3
 *
 * @author houbinbin
 * @version 1.0
 * @since 1.7
 */
public class FutureData implements Data {

    private RealData realData;

    private boolean isReady = false;

    public synchronized void setRealData(RealData realData) {
        if(isReady) {
            return; //balk
        }

        this.realData = realData;
        this.isReady = true;
        notifyAll();
    }

    @Override
    public synchronized String getContent() {
        while (!isReady) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        return this.realData.getContent();
    }

}
  • Data.java
package com.github.houbb.thread.learn.easy.learn.future;

/**
 * 2018/2/3
 *
 * @author houbinbin
 * @version 1.0
 * @since 1.7
 */
public interface Data {

    String getContent();

}
  • Host.java
package com.github.houbb.thread.learn.easy.learn.future;

/**
 * 2018/2/3
 *
 * @author houbinbin
 * @version 1.0
 * @since 1.7
 */
public class Host {

    public Data request(final String string) {
        //
        System.out.println("Host.request() START...");

        //1. future
        final FutureData futureData = new FutureData();


        //2.
        new Thread(new Runnable() {
            @Override
            public void run() {
                RealData realData = new RealData(string);
                futureData.setRealData(realData);
            }
        }).start();


        System.out.println("Host.request() END...");
        return futureData;
    }

}
  • RealData.java
package com.github.houbb.thread.learn.easy.learn.future;

import com.github.houbb.thread.learn.easy.learn.ThreadUtil;

/**
 * 2018/2/3
 *
 * @author houbinbin
 * @version 1.0
 * @since 1.7
 */
public class RealData implements Data {

    private final String string;

    public RealData(String string) {
        ThreadUtil.sleep(1000);
        this.string = string+"-real";
    }

    @Override
    public String getContent() {
        return this.string;
    }

}

测试

  • Main.java
package com.github.houbb.thread.learn.easy.learn.future;

/**
 * 2018/2/3
 *
 * @author houbinbin
 * @version 1.0
 * @since 1.7
 */
public class Main {

    public static void main(String[] args) {
        Data futureDataA = new Host().request("A");
        Data futureDataB = new Host().request("C");
        Data futureDataC = new Host().request("D");

        System.out.println(futureDataA.getContent());
        System.out.println(futureDataB.getContent());
        System.out.println(futureDataC.getContent());
    }

}
  • 测试结果
Host.request() START...
Host.request() END...
Host.request() START...
Host.request() END...
Host.request() START...
Host.request() END...
A-real
C-real
D-real

实现方式

UML & Code

UML

Future

Code

代码地址

future

系列导航

多线程系列导航