tomcat-启动时启动额外线程并控制线程状态

[b]通过启动线程可以进行后台的操作[/b]

[b]1.创建servlet[/b]

package com.wuhao.itinfo.action;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.*;

public class GrabBlogHtmlAction extends HttpServlet {
    /**
     * function:control thread state
     * 
	 * @author wuhao
	 */
	private static final long serialVersionUID = 1L;

	private GrabBlogThread gbt;
	private String method;

	@Override
	public void init() throws ServletException {
		gbt = new GrabBlogThread();
		gbt.start();
	}

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//get start or stop thread
		method = (String) request.getParameter("method");

		if("stop".equals(method)){
			//stop thread
			if(gbt != null){
				gbt.stopThread();
				gbt = null;
				System.gc();
				System.out.println("stop thread");
			}
		}else if("start".equals(method)){
			System.out.println("start thread" + gbt);
			//start thread
			if(gbt == null || !gbt.isAlive()){
				gbt = new GrabBlogThread();
				gbt.start();
			}
			System.out.println("start thread");
		}else{
			System.out.println("nothing to do");
		}
	}

	/***
	 * 
	 * */
	class GrabBlogThread extends Thread 
    {
		//thread stop sign
		private volatile boolean stopSign = true;

		//stop thread
		public void stopThread(){
			stopSign = false;
		}
		public void startThread(){
			stopSign = true;
		}

		@Override
		public void run() {
	          while(stopSign){
             	 System.out.println("thread run: " + stopSign);
             	 try {
					sleep(10000);
				 } catch (InterruptedException e) {
					e.printStackTrace();
				 }
              }
		}	
    } 

}

[b]2.配置web.xml[/b]

	
	
	    GRABHTML
	    com.wuhao.itinfo.action.GrabBlogHtmlAction
	    1
	
	   
  		GRABHTML   
 		 /grabblogaction   
	
	

[b]3.测试[/b]
启动tomcat：
thread run: true
thread run: true

停止线程：
http://localhost:8080/itinfo/grabblogaction?method=stop
thread run: true
thread run: true
stop thread

启动线程：
http://localhost:8080/itinfo/grabblogaction?method=start

thread run: true
stop thread
start threadnull
start thread
thread run: true
thread run: true