多線程寫入文本文件

希望你能幫助我這個。我需要製作一個程序，使用多個線程寫入文本文件。我需要的是顯示處理器如何給一個線程或另一個線程「注意」，所以基本上，我需要同時運行的所有線程，當然還需要同時寫入。多線程寫入文本文件

這是我的代碼。方法1：使用「for」來創建和啓動線程。

public class ThreadGenerator { 

    public static void main(String[] args) { 

     File textFile = new File("c:\\threadLog.txt"); 

     try { 
      PrintWriter out = new PrintWriter(new FileWriter(textFile)); 

      for (int index = 0; index < 5; index++) { 

      ThreadCustom thread = new ThreadCustom("ID" + index, out); 
      thread.start(); 
      } 

      out.close(); 

     } catch (IOException ex) { 
      Logger.getLogger(ThreadGenerator.class.getName()).log(Level.SEVERE, null, ex); 
     } 

    } 
}

方法2：創建和啓動每個線程手動

public class ThreadGenerator { 

    public static void main(String[] args) { 

     File textFile = new File("c:\\threadLog.txt"); 

     try { 
      PrintWriter out = new PrintWriter(new FileWriter(textFile)); 

      ThreadCustom thread1 = new ThreadCustom("ID1", out); 
      ThreadCustom thread2 = new ThreadCustom("ID2", out); 
      ThreadCustom thread3 = new ThreadCustom("ID3", out); 
      ThreadCustom thread4 = new ThreadCustom("ID4", out); 
      ThreadCustom thread5 = new ThreadCustom("ID5", out); 
      thread1.start(); 
      thread2.start(); 
      thread3.start(); 
      thread4.start(); 
      thread5.start(); 

      out.close(); 

     } catch (IOException ex) { 
      Logger.getLogger(ThreadGenerator.class.getName()).log(Level.SEVERE, null, ex); 
     } 

    } 
}

這是我ThreadCustom類

public class ThreadCustom extends Thread { 

    private String threadId; 
    private PrintWriter out; 

    public ThreadCustom(String threadId, PrintWriter out){ 

     this.threadId = threadId; 
     this.out = out; 
    } 

    @Override 
    public void run(){ 

     DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss"); 
     Calendar cal = Calendar.getInstance(); 

      this.out.println("Thread ID: "+this.threadId+" Enter Time: "+cal.getTime()+"\n"); 
      for(int index = 0; index < 10000; index++){ 

       this.out.println("Thread ID: "+this.threadId+" Current Time: "+cal.getTime()+"\n"); 
      } 
      this.out.println("Thread ID: "+this.threadId+" Exit Time: "+cal.getTime()+"\n"); 
    } 
}

所以，你可以看到，我創建了一個PrinterWriter，並給它作爲創建ThreadCustom對象的參數，所以所有線程都使用相同的PrinterWriter對象（java中的所有對象都作爲參考傳遞，對嗎？）

我期待得到什麼？像這樣的東西

Thread ID: ID0 Enter Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID1 Enter Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID1 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID1 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID Exit Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID1 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID0 Current Time: Fri Jan 27 00:38:54 CLST 2012 
Thread ID: ID1 Exit Time: Fri Jan 27 00:38:54 CLST 2012

或類似的東西。

希望你能幫助我！

在此先感謝社區！ PS：使用.start（）確實會創建.txt，但不會寫任何東西，但是，如果我使用.run（）而不是.start（），它會寫入.txt，但是（ID0，ID1，ID3等）

來源

2012-01-27 Diego

您必須等待您的線程在關閉輸出之前完成其工作。最簡單的方法是使用join。

thread1.start(); 
    thread2.start(); 
    thread3.start(); 
    thread4.start(); 
    thread5.start(); 

    thread1.join(); 
    thread2.join(); 
    thread3.join(); 
    thread4.join(); 
    thread5.join(); 

    out.close();

來源

2012-01-27 03:50:29

多線程寫入文本文件

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