java简单实现多线程及线程池实例详解

本文为大家分享了java多线程的简单实现及线程池实例，供大家参考，具体内容如下

一、多线程的两种实现方式

1、继承Thread类的多线程

/**  * 继承Thread类的多线程简单实现  */ public class extThread extends Thread {        public void run(){       for(int i=0;i<100;i++){         System.out.println(getName()+"-"+i);       }    }        public static void main(String arg[]){       for(int i=0;i<100;i++){         System.out.println(Thread.currentThread().getName()+"-"+i);         if(i==50){            new extThread().start();            new extThread().start();         }       }    } } 

2、实现Runnable接口的多线程

/**  * 实现runable接口的多线程实例  */ public class runThread implements Runnable {    public void run(){       for(int i=0;i<100;i++){         System.out.println(Thread.currentThread().getName()+"-"+i);       }    }        public static void main(String arg[]){       for(int i=0;i<100;i++){         System.out.println(Thread.currentThread().getName()+"-"+i);         if(i==50){            runThread rt = new runThread();            new Thread(rt,"新线程1").start();            new Thread(rt,"新线程2").start();         }       }    }     } 

二、线程池的简单实现

//实现Runnable接口 class TestThread implements Runnable{      public void run() {     for(int i = 0;i < 100;i++){       System.out.println(Thread.currentThread().getName() + "i的值为：" + i);     }   } }  public class threadPoolTest {      public static void main(String[] args) {     //创建一个具有固定线程数的线程池     ExecutorService pool = Executors.newFixedThreadPool(5);     //向线程池中提交三个线程     pool.submit(new TestThread());     pool.submit(new TestThread());     pool.submit(new TestThread());     //关闭线程池     pool.shutdown();   }  } 

三、java爬虫使用线程池实例

/**  * 爬虫调度线程池  */ public class threadPool {    public static HashMap<String, Spiders> statusMap = new HashMap<String, Spiders>();   // 存放爬虫，key为爬虫的id，value为爬虫的线程池   static HashMap<Integer, ThreadPoolExecutor> threadMap = new HashMap<Integer, ThreadPoolExecutor>();   //创建一个线程池   static ThreadPoolExecutor threadPool = new ThreadPoolExecutor(200, 230,80000L,        TimeUnit.SECONDS,        new ArrayBlockingQueue<Runnable>(10),       new ThreadPoolExecutor.CallerRunsPolicy());    public static void executeThread(Spiders spider) {     statusMap.put(String.valueOf(spider.getId()), spider);     // 爬虫有效     if (spider.getFlag() == 0) {       if (spider.getStatus() == 0) {         // 表示爬虫进入抓取状态         ThreadPoolExecutor detailPool = null;         if (threadMap.get(spider.getId()) == null) {           detailPool = new ThreadPoolExecutor(30, 80, 80000L,               TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(                   10),               new ThreadPoolExecutor.CallerRunsPolicy());           threadMap.put(spider.getId(), detailPool);           threadPool.execute(new threadRun(spider, threadMap));         }       }     }   } }  //实现Runnable接口 class threadRun implements Runnable {    private HashMap<Integer, ThreadPoolExecutor> threadPoolMap;   private Spiders spider;    public threadRun(Spiders spider,       HashMap<Integer, ThreadPoolExecutor> threadPoolMap) {     this.threadPoolMap = threadPoolMap;     this.spider = spider;   }    //线程执行体   public void run() {     try {       if ("rong360".equals(spider.getWebsite())) {         new RongThread(threadPoolMap.get(spider.getId()), spider)             .startSpider();       } else if ("xxgg_sd".equals(spider.getWebsite())) {         new Spider_ShanDong(threadPoolMap.get(spider             .getId()), spider).startSpider();       } else if ("xxgg_gz".equals(spider.getWebsite())) {         new Spider_GuiZhou(threadPoolMap.get(spider             .getId()), spider).startSpider();       } else if ("sx".equals(spider.getWebsite())) {         new SpiderSX(spider).startSpider();       } else if ("baidu".equals(spider.getWebsite())) {         new SpiderBaiDu(spider).startSpider();       } else if ("11315".equals(spider.getWebsite())) {         new Spider11315ByName(spider).startSpider();       }      } catch (Exception e) {       e.printStackTrace();     }   }  } 

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