给web 服务器后台加线程

一。新建一个servlet{

Java代码

1. package com.ibox.init;   
2. import java.io.IOException;   
3. import java.io.PrintWriter;   
4. import javax.servlet.ServletContext;   
5. import javax.servlet.ServletException;   
6. import javax.servlet.http.HttpServlet;   
7. import javax.servlet.http.HttpServletRequest;   
8. import javax.servlet.http.HttpServletResponse;   
9. import com.ibox.util.ServerTimer;   
10.   
11. public class InitServlet extends HttpServlet {   
12.  public InitServlet() {   
13.   super();   
14.  }   
15.  public void destroy() {   
16.   super.destroy(); // Just puts "destroy" string in log   
17.   // Put your code here   
18.  }   
19.  public void doGet(HttpServletRequest request, HttpServletResponse response)   
20.    throws ServletException, IOException {   
21.   doPost(request, response);   
22.  }   
23.  public void doPost(HttpServletRequest request, HttpServletResponse response)   
24.    throws ServletException, IOException {   
25.  }   
26.  public void init() throws ServletException {   
27.      
28.   ServletContext application = getServletConfig().getServletContext();   
29.   String realpath = this.getServletContext().getRealPath("/");   
30.   new ServerTimer(application,realpath).start();   
31.      
32.  }   
33. }  

package com.ibox.init;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.ibox.util.ServerTimer;public class InitServlet extends HttpServlet { public InitServlet() {  super(); } public void destroy() {  super.destroy(); // Just puts "destroy" string in log  // Put your code here } public void doGet(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException {  doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response)   throws ServletException, IOException { } public void init() throws ServletException {    ServletContext application = getServletConfig().getServletContext();  String realpath = this.getServletContext().getRealPath("/");  new ServerTimer(application,realpath).start();   }}

}
二。在web.xml配这个servlet{

Java代码

1. <!-- 初始化信息 -->   
2. <servlet>   
3.   <servlet-name>InitValue</servlet-name>   
4.   <servlet-class>com.ibox.init.InitServlet</servlet-class>   
5.   <load-on-startup>7</load-on-startup>   
6. </servlet>  

  <!-- 初始化信息 -->  <servlet>    <servlet-name>InitValue</servlet-name>    <servlet-class>com.ibox.init.InitServlet</servlet-class>    <load-on-startup>7</load-on-startup>  </servlet>

}
三。新建serverTimer线程类｛

Java代码

1. package com.ibox.util;   
2. import java.util.Date;   
3. import javax.servlet.ServletContext;   
4. public class ServerTimer extends Thread {   
5.  ServletContext application = null;   
6.  String realpath = "";   
7.  int step = 1000;   
8.  public ServerTimer(ServletContext application,String realpath){   
9.   this.application = application;   
10.   this.realpath = realpath;   
11.  }   
12.  public ServerTimer(ServletContext application,String realpath,int step){   
13.   this.application = application;   
14.   this.realpath = realpath;   
15.   this.step = step;   
16.  }   
17.  public void run(){   
18.   while(true){   
19.    ServerTimerInterface st = new GetServetTime();   
20.    st.timerStart(application);   
21.    try{   
22.     Thread.sleep(step);   
23.    }catch (Exception e) {   
24.     e.printStackTrace();   
25.    }   
26.   }   
27.  }   
28. }  

package com.ibox.util;import java.util.Date;import javax.servlet.ServletContext;public class ServerTimer extends Thread { ServletContext application = null; String realpath = ""; int step = 1000; public ServerTimer(ServletContext application,String realpath){  this.application = application;  this.realpath = realpath; } public ServerTimer(ServletContext application,String realpath,int step){  this.application = application;  this.realpath = realpath;  this.step = step; } public void run(){  while(true){   ServerTimerInterface st = new GetServetTime();   st.timerStart(application);   try{    Thread.sleep(step);   }catch (Exception e) {    e.printStackTrace();   }  } }}

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四。新建执行接口｛

Java代码

1. package com.ibox.util;   
2. import javax.servlet.ServletContext;   
3.   
4. public interface ServerTimerInterface {   
5.  public void timerStart();   
6.  public void timerStart(ServletContext application);   
7. }  

package com.ibox.util;import javax.servlet.ServletContext;public interface ServerTimerInterface { public void timerStart(); public void timerStart(ServletContext application);}

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五。实现执行方法｛

Java代码

1. package com.ibox.util;   
2. import java.util.Date;   
3. import javax.servlet.ServletContext;   
4.   
5. public class GetServetTime implements ServerTimerInterface {   
6.  public void timerStart() {   
7.  }   
8.  public void timerStart(ServletContext application) {   
9. //  String cpumsg = new GetCPU().getCpu(realpath);   
10.   Date date = new Date();   
11.   int year = date.getYear() + 1900;   
12.   int month = date.getMonth()+1;   
13.   int d = date.getDate();   
14.   int day = date.getDay();   
15.   int hour = date.getHours();   
16.   int min = date.getMinutes();   
17.   int sec = date.getSeconds();   
18.   String timeStr = ""+year+" "+month+" "+" "+addZero(hour)+":"+addZero(min)+":"+addZero(sec);   
19.   application.setAttribute("nowtime", timeStr);   
20.      
21.  }   
22.     
23.  private String addZero(int a){   
24.   String s = "";   
25.   if(a < 10){   
26.    s = "0"+a;   
27.   }else{   
28.    s = ""+a;   
29.   }   
30.   return s;   
31.  }   
32. }  

package com.ibox.util;import java.util.Date;import javax.servlet.ServletContext;public class GetServetTime implements ServerTimerInterface { public void timerStart() { } public void timerStart(ServletContext application) {//  String cpumsg = new GetCPU().getCpu(realpath);  Date date = new Date();  int year = date.getYear() + 1900;  int month = date.getMonth()+1;  int d = date.getDate();  int day = date.getDay();  int hour = date.getHours();  int min = date.getMinutes();  int sec = date.getSeconds();  String timeStr = ""+year+" "+month+" "+" "+addZero(hour)+":"+addZero(min)+":"+addZero(sec);  application.setAttribute("nowtime", timeStr);   }  private String addZero(int a){  String s = "";  if(a < 10){   s = "0"+a;  }else{   s = ""+a;  }  return s; }}

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本例为获取服务器时间并存入application内
本例只开了一个线程，基本够用，如需更多线程，要改源码
（按提示顺序建类会报错，但都建完就好了，也可倒序建）