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77 lines
1.8 KiB
Java
77 lines
1.8 KiB
Java
Count total number of live sessions in a web application
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--- JSP page for testing (test.jsp) --
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<%
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Integer icount = (Integer)session.getAttribute("count");
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out.println("total live sessions "+icount);
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%>
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--- Servlet that handles session count --
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import javax.servlet.*;
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import javax.servlet.http.*;
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public final class CounterListener implements HttpSessionListener
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{
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private int count = 1;
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private ServletContext context = null;
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public synchronized void sessionCreated(HttpSessionEvent se)
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{
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count++;
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log("sessionCreated("+se.getSession().getId()+") count="+count);
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se.getSession().setAttribute("count",new Integer(count));
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}
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public synchronized void sessionDestroyed(HttpSessionEvent se)
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{
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count--;
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log("sessionDestroyed("+se.getSession().getId()+") count="+count);
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se.getSession().setAttribute("count",new Integer(count));
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}
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public int getCount()
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{
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return this.count;
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}
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public void addCount()
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{
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count++;
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}
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private void log(String message)
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{
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if (context != null)
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context.log("SessionListener: " + message);
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else
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System.out.println("SessionListener: " + message);
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}
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}//close class CounterListener
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--- web.xml file modification --
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<?xml version="1.0" encoding="ISO-8859-1"?>
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<!DOCTYPE web-app
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PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
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"http://java.sun.com/dtd/web-app_2_3.dtd">
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<web-app>
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<display-name>Welcome to Tomcat</display-name>
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<!-- add this line of code -->
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<listener>
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<listener-class>CounterListener</listener-class>
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</listener>
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<description>
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Welcome to Tomcat
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</description>
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</web-app>
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