java簡單實現多線程及線程池實例詳解

更新時間：2018年03月23日 09:35:47 作者：shao-hang

這篇文章主要為大家詳細介紹了java簡單實現多線程，及java爬蟲使用線程池實例，具有一定的參考價值，感興趣的小伙伴們可以參考一下

本文為大家分享了java多線程的簡單實現及線程池實例，供大家參考，具體內容如下

一、多線程的兩種實現方式

1、繼承Thread類的多線程

/** 
 * 繼承Thread類的多線程簡單實現 
 */ 
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、實現Runnable接口的多線程

/** 
 * 實現runable接口的多線程實例 
 */ 
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,"新線程1").start(); 
           new Thread(rt,"新線程2").start(); 
        } 
      } 
   } 
    
}

二、線程池的簡單實現

//實現Runnable接口 
class TestThread implements Runnable{ 
   
  public void run() { 
    for(int i = 0;i < 100;i++){ 
      System.out.println(Thread.currentThread().getName() + "i的值為：" + i); 
    } 
  } 
} 
 
public class threadPoolTest { 
   
  public static void main(String[] args) { 
    //創(chuàng)建一個具有固定線程數的線程池 
    ExecutorService pool = Executors.newFixedThreadPool(5); 
    //向線程池中提交三個線程 
    pool.submit(new TestThread()); 
    pool.submit(new TestThread()); 
    pool.submit(new TestThread()); 
    //關閉線程池 
    pool.shutdown(); 
  } 
 
}

三、java爬蟲使用線程池實例

/** 
 * 爬蟲調度線程池 
 */ 
public class threadPool { 
 
  public static HashMap<String, Spiders> statusMap = new HashMap<String, Spiders>(); 
  // 存放爬蟲，key為爬蟲的id，value為爬蟲的線程池 
  static HashMap<Integer, ThreadPoolExecutor> threadMap = new HashMap<Integer, ThreadPoolExecutor>(); 
  //創(chuàng)建一個線程池 
  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); 
    // 爬蟲有效 
    if (spider.getFlag() == 0) { 
      if (spider.getStatus() == 0) { 
        // 表示爬蟲進入抓取狀態(tài) 
        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)); 
        } 
      } 
    } 
  } 
} 
 
//實現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; 
  } 
 
  //線程執(zhí)行體 
  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(); 
    } 
  } 
 
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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