现在的位置: 首页 > java > j2se > 正文
小 中 大
使用Executors创建和管理线程
2012年08月02日 ⁄ j2se ⁄ 共 9012字 ⁄ 暂无评论

1. 类 Executors
此类中提供的一些方法有：
1.1 public static ExecutorService newCachedThreadPool()
创建一个可根据需要创建新线程的线程池，但是在以前构造的线程可用时将重用它们。对于执行很多短期异步任务的程序而言，这些线程池通常可提高程序性能。

1.2 public static ExecutorService newFixedThreadPool(int nThreads)
创建一个可重用固定线程数的线程池，以共享的无界队列方式来运行这些线程。

1.3 public static ExecutorService newSingleThreadExecutor()
创建一个使用单个 worker 线程的 Executor，以无界队列方式来运行该线程。

这三个方法都可以配合接口ThreadFactory的实例一起使用。并且返回一个ExecutorService接口的实例。
2. 接口 ThreadFactory
根据需要创建新线程的对象。使用线程工厂就无需再手工编写对 new Thread 的调用了，从而允许应用程序使用特殊的线程子类、属性等等。
此接口最简单的实现就是：

  1. class SimpleThreadFactory implements ThreadFactory {   
  2.    public Thread newThread(Runnable r) {   
  3.      return new Thread(r);   
  4.    }   
  5.  }  
  6. 3. 接口ExecutorService
    该接口提供了管理终止的方法。
    4.创建标准线程池启动线程
    4.1 提供一个简单的实现Runnable接口的线程
    MyThread.java
    1. package com.zj.concurrency.executors;   
    2.     
    3. public class MyThread implements Runnable {   
    4.     private int count = 1, number;   
    5.     
    6.     public MyThread(int num) {   
    7.        number = num;   
    8.        System.out.println("Create Thread-" + number);   
    9.     }   
    10.     
    11.     public void run() {   
    12.        while (true) {   
    13.            System.out.println("Thread-" + number + " run " + count+" time(s)");   
    14.            if (++count == 3)   
    15.               return;   
    16.        }   
    17.     }   
    18. }  这个线程会打印出相应的创建和执行信息。
      4.2使用CachedThreadPool启动线程
      CachedThreadPool.java
      1. package com.zj.concurrency.executors;   
      2. import java.util.concurrent.ExecutorService;   
      3. import java.util.concurrent.Executors;   
      4.     
      5. public class CachedThreadPool {   
      6.     public static void main(String[] args) {   
      7.        ExecutorService exec = Executors.newCachedThreadPool();   
      8.        for (int i = 0; i < 5; i++)   
      9.            exec.execute(new MyThread(i));   
      10.        exec.shutdown();   
      11.     }   
      12. }  
      13. 结果：
        Create Thread-0
        Create Thread-1
        Create Thread-2
        Create Thread-3
        Thread-0 run 1 time(s)
        Thread-0 run 2 time(s)
        Thread-1 run 1 time(s)
        Thread-1 run 2 time(s)
        Thread-2 run 1 time(s)
        Thread-2 run 2 time(s)
        Create Thread-4
        Thread-4 run 1 time(s)
        Thread-4 run 2 time(s)
        Thread-3 run 1 time(s)
        Thread-3 run 2 time(s)

        4.3 使用FixedThreadPool启动线程
        FixedThreadPool.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors;   
        2. import java.util.concurrent.ExecutorService;   
        3. import java.util.concurrent.Executors;   
        4.     
        5. public class FixedThreadPool {   
        6.     public static void main(String[] args) {   
        7.        ExecutorService exec = Executors.newFixedThreadPool(2);   
        8.        for (int i = 0; i < 5; i++)   
        9.            exec.execute(new MyThread(i));   
        10.        exec.shutdown();   
        11.     }   
        12. }  
        package com.zj.concurrency.executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class FixedThreadPool {
    public static void main(String[] args) {
       ExecutorService exec = Executors.newFixedThreadPool(2);
       for (int i = 0; i < 5; i++)
           exec.execute(new MyThread(i));
       exec.shutdown();
    }
}

        结果：
        Create Thread-0
        Create Thread-1
        Create Thread-2
        Create Thread-3
        Create Thread-4
        Thread-0 run 1 time(s)
        Thread-0 run 2 time(s)
        Thread-2 run 1 time(s)
        Thread-2 run 2 time(s)
        Thread-3 run 1 time(s)
        Thread-3 run 2 time(s)
        Thread-4 run 1 time(s)
        Thread-4 run 2 time(s)
        Thread-1 run 1 time(s)
        Thread-1 run 2 time(s)

        4.4 使用SingleThreadExecutor启动线程
        SingleThreadExecutor.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors;   
        2. import java.util.concurrent.ExecutorService;   
        3. import java.util.concurrent.Executors;   
        4.     
        5. public class SingleThreadExecutor {   
        6.     public static void main(String[] args) {   
        7.        ExecutorService exec = Executors.newSingleThreadExecutor();   
        8.        for (int i = 0; i < 5; i++)   
        9.            exec.execute(new MyThread(i));   
        10.        exec.shutdown();   
        11.     }   
        12. }  
        package com.zj.concurrency.executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class SingleThreadExecutor {
    public static void main(String[] args) {
       ExecutorService exec = Executors.newSingleThreadExecutor();
       for (int i = 0; i < 5; i++)
           exec.execute(new MyThread(i));
       exec.shutdown();
    }
}

        结果：
        Create Thread-0
        Create Thread-1
        Create Thread-2
        Create Thread-3
        Create Thread-4
        Thread-0 run 1 time(s)
        Thread-0 run 2 time(s)
        Thread-1 run 1 time(s)
        Thread-1 run 2 time(s)
        Thread-2 run 1 time(s)
        Thread-2 run 2 time(s)
        Thread-3 run 1 time(s)
        Thread-3 run 2 time(s)
        Thread-4 run 1 time(s)
        Thread-4 run 2 time(s)
        5.配合ThreadFactory接口的使用
        我们试图给线程加入daemon和priority的属性设置。
        5.1设置后台线程属性
        DaemonThreadFactory.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors.factory;   
        2. import java.util.concurrent.ThreadFactory;   
        3.     
        4. public class DaemonThreadFactory implements ThreadFactory {   
        5.     public Thread newThread(Runnable r) {   
        6.        Thread t = new Thread(r);   
        7.        t.setDaemon(true);   
        8.        return t;   
        9.     }   
        10. }  
        package com.zj.concurrency.executors.factory;
import java.util.concurrent.ThreadFactory;

public class DaemonThreadFactory implements ThreadFactory {
    public Thread newThread(Runnable r) {
       Thread t = new Thread(r);
       t.setDaemon(true);
       return t;
    }
}

        5.2 设置优先级属性
        最高优先级MaxPriorityThreadFactory.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors.factory;   
        2. import java.util.concurrent.ThreadFactory;   
        3.     
        4. public class MaxPriorityThreadFactory implements ThreadFactory {   
        5.     public Thread newThread(Runnable r) {   
        6.        Thread t = new Thread(r);   
        7.        t.setPriority(Thread.MAX_PRIORITY);   
        8.        return t;   
        9.     }   
        10. }  
        package com.zj.concurrency.executors.factory;
import java.util.concurrent.ThreadFactory;

public class MaxPriorityThreadFactory implements ThreadFactory {
    public Thread newThread(Runnable r) {
       Thread t = new Thread(r);
       t.setPriority(Thread.MAX_PRIORITY);
       return t;
    }
}

        最低优先级MinPriorityThreadFactory.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors.factory;   
        2. import java.util.concurrent.ThreadFactory;   
        3.     
        4. public class MinPriorityThreadFactory implements ThreadFactory {   
        5.     public Thread newThread(Runnable r) {   
        6.        Thread t = new Thread(r);   
        7.        t.setPriority(Thread.MIN_PRIORITY);   
        8.        return t;   
        9.     }   
        10. }  
        package com.zj.concurrency.executors.factory;
import java.util.concurrent.ThreadFactory;

public class MinPriorityThreadFactory implements ThreadFactory {
    public Thread newThread(Runnable r) {
       Thread t = new Thread(r);
       t.setPriority(Thread.MIN_PRIORITY);
       return t;
    }
}

        5.3启动带有属性设置的线程
        ExecFromFactory.java

        Java代码 复制代码 收藏代码
        1. package com.zj.concurrency.executors;   
        2. import java.util.concurrent.ExecutorService;   
        3. import java.util.concurrent.Executors;   
        4. import com.zj.concurrency.executors.factory.DaemonThreadFactory;   
        5. import com.zj.concurrency.executors.factory.MaxPriorityThreadFactory;   
        6. import com.zj.concurrency.executors.factory.MinPriorityThreadFactory;   
        7.     
        8. public class ExecFromFactory {   
        9.     public static void main(String[] args) throws Exception {   
        10.        ExecutorService defaultExec = Executors.newCachedThreadPool();   
        11.        ExecutorService daemonExec = Executors   
        12.               .newCachedThreadPool(new DaemonThreadFactory());   
        13.        ExecutorService maxPriorityExec = Executors   
        14.               .newCachedThreadPool(new MaxPriorityThreadFactory());   
        15.        ExecutorService minPriorityExec = Executors   
        16.               .newCachedThreadPool(new MinPriorityThreadFactory());   
        17.        for (int i = 0; i < 10; i++)   
        18.            daemonExec.execute(new MyThread(i));   
        19.        for (int i = 10; i < 20; i++)   
        20.            if (i == 10)   
        21.               maxPriorityExec.execute(new MyThread(i));   
        22.            else if (i == 11)   
        23.               minPriorityExec.execute(new MyThread(i));   
        24.            else  
        25.               defaultExec.execute(new MyThread(i));   
        26.     }   
        27. }  
        package com.zj.concurrency.executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import com.zj.concurrency.executors.factory.DaemonThreadFactory;
import com.zj.concurrency.executors.factory.MaxPriorityThreadFactory;
import com.zj.concurrency.executors.factory.MinPriorityThreadFactory;

public class ExecFromFactory {
    public static void main(String[] args) throws Exception {
       ExecutorService defaultExec = Executors.newCachedThreadPool();
       ExecutorService daemonExec = Executors
              .newCachedThreadPool(new DaemonThreadFactory());
       ExecutorService maxPriorityExec = Executors
              .newCachedThreadPool(new MaxPriorityThreadFactory());
       ExecutorService minPriorityExec = Executors
              .newCachedThreadPool(new MinPriorityThreadFactory());
       for (int i = 0; i < 10; i++)
           daemonExec.execute(new MyThread(i));
       for (int i = 10; i < 20; i++)
           if (i == 10)
              maxPriorityExec.execute(new MyThread(i));
           else if (i == 11)
              minPriorityExec.execute(new MyThread(i));
           else
              defaultExec.execute(new MyThread(i));
    }
}

        结果：
        Create Thread-0
        Create Thread-1
        Create Thread-2
        Create Thread-3
        Thread-0 run 1 time(s)
        Thread-0 run 2 time(s)
        Thread-1 run 1 time(s)
        Thread-1 run 2 time(s)
        Thread-2 run 1 time(s)
        Thread-2 run 2 time(s)
        Create Thread-4
        Thread-4 run 1 time(s)
        Thread-4 run 2 time(s)
        Create Thread-5
        Thread-5 run 1 time(s)
        Thread-5 run 2 time(s)
        Create Thread-6
        Create Thread-7
        Thread-7 run 1 time(s)
        Thread-7 run 2 time(s)
        Create Thread-8
        Thread-8 run 1 time(s)
        Thread-8 run 2 time(s)
        Create Thread-9
        Create Thread-10
        Thread-10 run 1 time(s)
        Thread-10 run 2 time(s)
        Create Thread-11
        Thread-9 run 1 time(s)
        Thread-9 run 2 time(s)
        Thread-6 run 1 time(s)
        Thread-6 run 2 time(s)
        Thread-3 run 1 time(s)
        Thread-3 run 2 time(s)
        Create Thread-12
        Create Thread-13
        Create Thread-14
        Thread-12 run 1 time(s)
        Thread-12 run 2 time(s)
        Thread-13 run 1 time(s)
        Thread-13 run 2 time(s)
        Create Thread-15
        Thread-15 run 1 time(s)
        Thread-15 run 2 time(s)
        Create Thread-16
        Thread-16 run 1 time(s)
        Thread-16 run 2 time(s)
        Create Thread-17
        Create Thread-18
        Create Thread-19
        Thread-14 run 1 time(s)
        Thread-14 run 2 time(s)
        Thread-17 run 1 time(s)
        Thread-17 run 2 time(s)
        Thread-18 run 1 time(s)
        Thread-18 run 2 time(s)
        Thread-19 run 1 time(s)
        Thread-19 run 2 time(s)
        Thread-11 run 1 time(s)
        Thread-11 run 2 time(s)

      14.   出自：http://zhangjunhd.blog.51cto.com/113473/70068

 

返回

作者:

【上篇】
【下篇】

您可能还会对这些文章感兴趣！

  1. 怎么脱离svn控制
  2. jlist设置单元格的高度
安装的wamp，但无法连接到phpmyadmin，提示403错误，服务器拒绝执行该请求
小型软件公司如何做大
jQuery & Ajax & JSONP
DISCUZ! X2.0 完美解决用户组上传论坛附件16M限制！

给我留言

您必须 [ 登录 ] 才能发表留言！

返回首页

Copyright © 2011-2019 糊涂虫  保留所有权利.   Theme by Robin
×