关于实现简单线程池的改写

import java.util.*; 
import java.lang.reflect.Array; 

/** 
* Created by IntelliJ IDEA. 
* User: Administrator 
* Date: 2008-7-7 
* Time: 9:07:56 
* To change this template use File | Settings | File Templates. 
*/ 
public class ThreadPool { 
//初始化空闲队列以及工作队列 
    List freeThreads = new ArrayList(); 
      List runThreads = new ArrayList(); 
//设置线程数量 
    private int size = 10; 
//设置关闭条件语句 
    boolean runflag=true; 
      public synchronized void stopthread() { 
           runflag=false; 
           runThreads.clear(); 
           Thread.interrupted(); 
      } 
       public synchronized boolean getrunflag(){ 
       return runflag; 
      } 
//线程池初始化 
    public ThreadPool(int size) { 
         this.size = size; 
         init(); 
      } 
      public ThreadPool() { 
         init(); 
      } 
//添加线程 
    private void init() { 

         for (int i = 0; i < size; i++) { 
               try{ 
                  MyThread thread = new MyThread(this, i); 
                  new Thread(thread).start(); 
                  freeThreads.add(thread); 
                    try { 
                         Thread.sleep(100); 
                          } catch (Exception e) {} 
                    }catch(Exception f){} 
             } 
      } 
// 运行线程 
public synchronized void runTask(Runnable task) { 

MyThread thread = (MyThread) freeThreads.remove(0); 
runThreads.add(thread); 
thread.setTask(task); 

} 
//释放线程 
public synchronized void free(MyThread thread) { 
runThreads.remove(thread); 
freeThreads.add(thread); 
} 
//显性显示信息 
public synchronized void print() { 
System.out.println("num:" + size); 
System.out.println("free: " + freeThreads.size()); 
System.out.println(freeThreads); 
System.out.println("run: " + runThreads.size()); 
System.out.println(runThreads); 
} 
//进行任务的线程 
public class MyThread implements Runnable { 

private ThreadPool pool; 
private Runnable task = null; 
private long start; 
private long end; 
private int num; 
private int sum = 0; 



public MyThread(ThreadPool pool, int num) { 
this.pool = pool; 
this.num = num; 
} 
//运行任务 
public void run() { 

while (getrunflag()) { 
start = System.currentTimeMillis(); 
try { 
if (task == null) { 
this.wait(); 
} 
task.run(); 
task = null; 
pool.free(this); 
end = System.currentTimeMillis(); 
sum += (end - start); 
getTime(); 
} catch (Exception e) { } 
} 
} 
public synchronized void setTask(Runnable task) { 
this.task = task; 
notifyAll(); 
} 
//显示工作线程 
public String toString() { 
return "Thread: " + num; 
} 
//获取时间 
public void getTime() { 
System.out.println(this + "\nTime:" + (end - start) + "s\nSum:" + sum); 
} 
} 
//测试 
public static void main(String[] args) throws Exception { 
ThreadPool pool = new ThreadPool(); 

pool.runTask(new Runnable() { 
public void run() { 
System.out.println("thread run No.1"); 
} 
}); 
pool.print(); 

pool.runTask(new Runnable() { 
public void run() { 
System.out.println("thread run No.2"); 
} 
}); 
pool.print(); 

pool.runTask(new Runnable() { 
public void run() { 
System.out.println("thread run No.3"); 
} 
}); 
pool.print(); 
//关闭线程池 
pool.stopthread(); 

} 
}