一个日志服务器的框架

package thread;

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
/**
* 一个日志服务的框架
* @author Administrator
*
*/

public class LoggerWriter {
private final BlockingQueue<String>queue;
private final LoggerThread loggerThread;

private final PrintWriter writer;
private boolean isShutdown;
private int reservations;
public LoggerWriter() throws FileNotFoundException{
   queue=new LinkedBlockingDeque<String>();
   loggerThread=new LoggerThread();
   writer=new PrintWriter("");
}

public void start(){
   loggerThread.start();
}
public void stop(){
   synchronized (this) {
    isShutdown=true;
   }
   loggerThread.interrupt();
}
public void log(String msg) throws InterruptedException{
   synchronized (this) {
    if(isShutdown)
     throw new IllegalStateException();
    ++reservations;
   }
   queue.put(msg);
}

private class LoggerThread extends Thread{
   public void run(){
   
    try {
     while (true) {
      try {
       synchronized (LoggerWriter.this) {
        if(isShutdown&&reservations==0)
         break;
       }
       String msg=queue.take();
       synchronized (LoggerWriter.this) {
        --reservations;
       }
       writer.print(msg);
      } catch (InterruptedException e) {
      
      }
     }
    } finally{
     writer.close();
    }
   
   }
  
}
}