timer用法

web.xml添加内容   建立Servlet
<servlet>
    <servlet-name>StatServlet</servlet-name>
    <servlet-class>cn.StatServlet</servlet-class>
    <init-param>
     <param-name>startTask</param-name>
     <param-value>true</param-value>
    </init-param>
    <init-param>
     <param-name>intervalTime</param-name >
     <param-value>1</param-value >
  </init-param>
    <load-on-startup >4</load-on-startup >
</servlet>
         <servlet-mapping>
             <servlet-name>StatServlet</servlet-name>
             <url-pattern>/StatServlet</url-pattern>
         </servlet-mapping>


StatServlet类
package cn;

import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class StatServlet extends HttpServlet { 
private static final long serialVersionUID = 1L;  

private Timer timer1 = null;  
  
private Task task1;  


public void destroy() {  
  
}  
  
public void doGet(HttpServletRequest request, HttpServletResponse response)  
        throws ServletException, IOException {  
      
}  

public void doPost(HttpServletRequest request, HttpServletResponse response)  
        throws ServletException, IOException {  
    doGet(request, response);         
}  

public void init() throws ServletException {  
      
    ServletContext context = getServletContext();  
      
    String startTask = getInitParameter("startTask");   
      
    if(startTask.equals("true")){  
        timer1 = new Timer(true);  
        task1 = new Task(context);
                 //每分钟访问一次 
        timer1.schedule((TimerTask) task1, 1000, 1000*60);  
    }  
}  
}  




Task类
package cn;

import java.io.IOException;
import java.util.TimerTask;

import javax.servlet.ServletContext;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.GetMethod;

import cn.yicha.pay.log.StatWhiteNameLogger;
 
public class Task extends TimerTask{  
public static final String REQUESTURL = "http://www.baidu.com";
public static boolean isOk = false;

    private ServletContext context;  
      
    private static boolean isRunning = true;  
      
    public Task(ServletContext context){  
        this.context = context;  
    }       
          
   
    public void run() {
      if(isRunning){ 
      HttpClient client = null;
      GetMethod getMethod = null;
      int statusCode=888;
      try {
client = new HttpClient();
getMethod = new GetMethod(REQUESTURL);
getMethod.setFollowRedirects(true);
//设置连接超时时间(单位毫秒)
client.setConnectionTimeout(10000);
//设置读数据超时时间(单位毫秒)
client.setTimeout(8000);
  //执行getMethod
     statusCode = client.executeMethod(getMethod);

  } catch (HttpException e) {
   //发生致命的异常，可能是协议不对或者返回的内容有问题
   e.printStackTrace();
  } catch (IOException e) {
   //发生网络异常
   e.printStackTrace();
  } finally {
if(statusCode==200||statusCode==302){
    isOk = true;
     }else{
    isOk = false;
     }
//记日志
StatLogger.log(statusCode,isOk);
System.out.println("状态码---->  "+statusCode+" isOk-------> "+isOk);
   //释放连接
getMethod.releaseConnection();
  }
      }  
}

}