线程池 有关问题求教

线程池 问题求教~

package a.b.threadpool;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class TpTest {
	public static void  main(String[] args){
		 BlockingQueue<Runnable> bqueue = new ArrayBlockingQueue<Runnable>(20); 
         
         ThreadPoolExecutor pool = new ThreadPoolExecutor(3,5,20,TimeUnit.MILLISECONDS,bqueue); 
         pool.execute(new XianChen("线程1"));
         pool.execute(new XianChen("线程2"));
         pool.execute(new XianChen("线程3"));
         pool.execute(new XianChen("线程4"));
         pool.execute(new XianChen("线程5"));
         pool.execute(new XianChen("线程6"));
         pool.execute(new XianChen("线程7"));
         pool.execute(new XianChen("线程8"));
         pool.execute(new XianChen("线程9"));
         pool.execute(new XianChen("线程10"));
         pool.execute(new XianChen("线程11"));
         pool.shutdown();
	}
}

class XianChen extends Thread{
	String name;
	XianChen(String name){
		this.name = name;
	}
	
	public void run() {
		System.out.println(Thread.currentThread().getName()+"进入");
		try {
			Thread.sleep(1500);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		//System.out.println(Thread.currentThread().getName()+"退出");
	}
}

new ThreadPoolExecutor(3,5,20,TimeUnit.MILLISECONDS,bqueue) 这个第二个参数的5 是不是最大的运行数？  我现在有11个线程需要运行， 那应该开放5个线程来处理吧 为何看结果他只开放3个呢？ 还是我理解有问题？ 刚看了下，执行时这样

public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue)

在这构造方法中，优先级处理任务的优先级为： 
核心线程corePoolSize、任务队列workQueue、最大线程maximumPoolSize。意思是只有当corePoolSize中任务满了，会先放到workQueue缓冲队列中，缓冲队列满了，才会放到maximumPoolSize里面去。