同時監控多個日誌文件

Question

我製作了一個程序，可以持續監控日誌文件。但我不知道如何監視多個日誌文件。這是我做的監控單個文件。我應該在下面的代碼中進行哪些更改，以便它還監視多個文件？

package com.read; 

import java.io.File; 
import java.io.IOException; 
import java.io.RandomAccessFile; 
import java.nio.channels.FileChannel; 
import java.nio.channels.FileLock; 
import java.util.Date; 
import java.util.Timer; 
import java.util.TimerTask; 
import java.util.logging.Level; 
import java.util.logging.Logger; 
import java.util.regex.Matcher; 
import java.util.regex.Pattern; 

public class FileWatcherTest { 

    public static void main(String args[]) { 

     final File fileName = new File("D:/logs/myFile.log"); 

     // monitor a single file 
     TimerTask fileWatcherTask = new FileWatcher(fileName) { 

      long addFileLen = fileName.length(); 
      FileChannel channel; 
      FileLock lock; 
      String a = ""; 
      String b = ""; 

      @Override 
      protected void onChange(File file) { 

       RandomAccessFile access = null; 
       try { 
        access = new RandomAccessFile(file, "rw"); 
        channel = access.getChannel(); 
        lock = channel.lock(); 
        if (file.length() < addFileLen) { 
         access.seek(file.length()); 
        } else { 
         access.seek(addFileLen); 
        } 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
       String line = null; 
       try { 

        while ((line = access.readLine()) != null) { 

         System.out.println(line); 

        } 

        addFileLen = file.length(); 

       } catch (IOException ex) { 
        Logger.getLogger(FileWatcherTest.class.getName()).log(
          Level.SEVERE, null, ex); 
       } 
       try { 
        lock.release(); 
       } catch (IOException e1) { 
        // TODO Auto-generated catch block 
        e1.printStackTrace(); 
       } // Close the file 

       try { 
        channel.close(); 
       } catch (IOException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } 

      } 

     }; 

     Timer timer = new Timer(); 
     // repeat the check every second 
     timer.schedule(fileWatcherTask, new Date(), 1000); 
    } 
} 




package com.read; 

import java.util.*; 
import java.io.*; 

public abstract class FileWatcher extends TimerTask { 

    private long timeStamp; 
    private File file; 
    static String s; 

    public FileWatcher(File file) { 
     this.file = file; 
     this.timeStamp = file.lastModified(); 
    } 

    public final void run() { 
     long timeStamp = file.lastModified(); 

     if (this.timeStamp != timeStamp) { 
      this.timeStamp = timeStamp; 

      onChange(file); 
     } 
    } 

    protected abstract void onChange(File file); 
} 

Answer 1

您應該使用線程。這裏有一個很好的教程：

http://docs.oracle.com/javase/tutorial/essential/concurrency/

你會做這樣的事情：

public class FileWatcherTest { 

    public static void main(String args[]) { 
     (new Thread(new FileWatcherRunnable("first.log"))).start(); 
     (new Thread(new FileWatcherRunnable("second.log"))).start(); 
    } 

    private static class FileWatcherRunnable implements Runnable { 
     private String logFilePath; 
     // you should inject the file path of the log file to watch 
     public FileWatcherRunnable(String logFilePath) { 
      this.logFilePath = logFilePath; 
     } 
     public void run() { 
      // your code from main goes in here 
     } 
    } 
}