ServletRequestListener的用法和實(shí)例

ServletRequestListener：
馬克- to-win：馬克 java社區(qū)：防盜版實(shí)名手機(jī)尾號(hào)： 73203。
ServletRequestListener能監(jiān)聽(tīng)到Request的生成和銷(xiāo)毀。



例 2.2.5.1

package com;
import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;
public class MyServletRequestListener implements
ServletRequestListener {
/*public void requestDestroyed(ServletRequestEvent sre)Notification that the servlet request is about to go out of scope. */
    public void requestDestroyed(ServletRequestEvent arg0) {
        System.out.println("馬克-to-win destroyed"+arg0.getServletRequest().getRemoteAddr());
    }
/*public void requestInitialized(ServletRequestEvent sre)Notification that the servlet request is about to go into scope. */
    public void requestInitialized(ServletRequestEvent arg0) {
        System.out.println("馬克-to-win request Initialized"+arg0.getServletRequest().getRemoteAddr());
    }
}


web.xml加入下面這段話：

  <listener>
    <listener-class>com.MyServletRequestListener</listener-class>
  </listener>







用下面這兩個(gè)servlet測(cè)試：


package com;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ServletHello1 extends HttpServlet {
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        System.out.println("ServletHello1 before");
        request.getRequestDispatcher("/ServletHello2").forward(request,response);
        System.out.println("這里會(huì)block5秒，ServletHello1 after");
    }
}




package com;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class ServletHello2 extends HttpServlet {
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("ServletHello2");
    }
}



運(yùn)行這個(gè)ServletHello1以后，  （如果ip地址是ipv6，比如： 0:0:0:0:0:0:0:1則換成http://127.0.0.1:8080/Filter2251/MarkToWinServlet）   console里的輸出結(jié)果是：

馬克-to-win request Initialized127.0.0.1
ServletHello1 before
ServletHello2
這里會(huì)block5秒，ServletHello1 after
馬克-to-win destroyed127.0.0.1