Java Guru: Hit Counter for a Web site, time of hitting and no. of current users

Many times you would be interested in knowing total number of hits of your site, time of hitting, and number of users currently using your site.

This post is about creating a hit counter that counts number of site visit. There are various ways for creating hit counter in servlet but here we have implemented hit counter using ServletContextListener. ServletContextListener is a listener interface that gets notified when the context is initialized and destroyed.

index.html

<body>

Username<input type="text" name="txtname" size="20"><br>

Password<input type="password" name="txtpass" size="20"><br>

</form>

</body>

LoginServlet

package nkpack;

import java.util.Date;

import java.io.IOException;

import java.io.PrintWriter;

import java.sql.*;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletConfig;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

/**

* @author Navindra Jha

public class LoginServlet extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");

PrintWriter out = response.getWriter();

Connection con=null;

try {

/* TODO output your page here*/

String name=request.getParameter("txtname");

String pass=request.getParameter("txtpass");

ServletConfig config=getServletConfig();

String dclass=config.getInitParameter("driverClass");

String cstr=config.getInitParameter("conStr");

Class.forName(dclass);

con=DriverManager.getConnection(cstr,"root","");

PreparedStatement pstmt=con.prepareStatement("select * from login where uname=? and upass=?");

pstmt.setString(1, name);

pstmt.setString(2, pass);

ResultSet rset=pstmt.executeQuery();

out.println("<body>");

if(rset.next())

{

Date d=new Date();

String time=d.getHours()+":"+d.getMinutes()+":"+d.getSeconds();

PreparedStatement stmt=con.prepareStatement("insert into logintime values(?,?)");

stmt.setString(1,name);

stmt.setString(2, time);

stmt.executeUpdate();

HttpSession session =request.getSession();

session.setAttribute("name", name);

RequestDispatcher rd=request.getRequestDispatcher("ViewServlet");

rd.forward(request, response);

}else

{

out.println("<h4>Invalid UserName or Password</h4>");

RequestDispatcher rd=request.getRequestDispatcher("index.html");

rd.include(request, response);

}

catch(Exception e){System.out.print(e);}

finally {

try {

out.close();

con.close();

} catch (SQLException ex) {

Logger.getLogger(LoginServlet.class.getName()).log(Level.SEVERE, null, ex);

}

ViewServlet

package nkpack;

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 javax.servlet.http.HttpSession;

/**

* @author Navindra Jha

public class ViewServlet extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");

PrintWriter out = response.getWriter();

HttpSession session=request.getSession();

String name=(String)session.getAttribute("name");

ServletContext ctx=getServletContext();

try {

out.println("<html>");

out.println("<head>");

out.println("<title>Servlet ViewServlet</title>");

out.println("</head>");

out.println("<body>");

out.println("<h2>Welcome to you, "+name+"</h2>");

out.println("Total Hits="+ctx.getAttribute("total"));

out.println("Current User="+ctx.getAttribute("current"));

out.println("<a href=LogoutServlet>Logout</a>");

out.println("<a href=HitSpecifier>Details of Hit</a>");

out.println("</body>");

out.println("</html>");

} finally {

out.close();

}

MyListener

package nkpack;

import java.io.IOException;

import javax.servlet.ServletContext;

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

import javax.servlet.ServletException;

import javax.servlet.http.HttpSessionEvent;

import javax.servlet.http.HttpSessionListener;

/**

* @author Navindra Jha

public class MyListener implements ServletContextListener,HttpSessionListener {

ServletContext ctx;

public void contextInitialized(ServletContextEvent sce) {

ctx=sce.getServletContext();

ctx.setAttribute("current",new Integer(0));

ctx.setAttribute("total",new Integer(0));

}

public void contextDestroyed(ServletContextEvent sce) {

throw new UnsupportedOperationException("Not supported yet.");

}

public void sessionCreated(HttpSessionEvent se) {

Integer t=(Integer)ctx.getAttribute("total");

Integer c=(Integer)ctx.getAttribute("current");

int tot=t.intValue();

int cur=c.intValue();

tot++;

cur++;

ctx.setAttribute("current", cur);

ctx.setAttribute("total", tot);

}

public void sessionDestroyed(HttpSessionEvent se) {

Integer c=(Integer)ctx.getAttribute("current");

int cur=c.intValue();

cur--;

ctx.setAttribute("current", new Integer(cur));

}

HitSpecifier

package nkpack;

import java.io.IOException;

import java.io.PrintWriter;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.servlet.ServletConfig;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* @author Navindra Jha

public class HitSpecifier extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");

PrintWriter out = response.getWriter();

out.println("Hit Details<br>");

Connection con=null;

try {

ServletConfig config = getServletConfig();

String dclass = config.getInitParameter("driverClass");

String cstr = config.getInitParameter("conStr");

Class.forName(dclass);

con = DriverManager.getConnection(cstr, "root", "");

System.out.println(con);

Statement pstmt = con.createStatement();

ResultSet rset = pstmt.executeQuery("SELECT * FROM logintime");

while (rset.next()) {

out.println(rset.getString(1)+" "+rset.getString(2));

out.println("<br>");

}

} catch (Exception e) {System.out.println(e);

} finally {

try {

out.close();

con.close();

} catch (SQLException ex) {

Logger.getLogger(HitSpecifier.class.getName()).log(Level.SEVERE, null, ex);

}

LogoutServlet

package nkpack;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

/**

* @author Navindra Jha

public class LogoutServlet extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");

HttpSession session=request.getSession();

session.invalidate();

PrintWriter out = response.getWriter();

try {

out.println("<html>");

out.println("<head>");

out.println("<title>Servlet LogoutServlet</title>");

out.println("</head>");

out.println("<body>");

out.println("<h1>You are Successfully logout</h1>");

out.print("<a href=LoginServlet>Aganin Login</a>");

out.println("</body>");

out.println("</html>");

} finally {

out.close();

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<listener-class>nkpack.MyListener</listener-class>

</listener>

<servlet-name>LoginServlet</servlet-name>

<servlet-class>nkpack.LoginServlet</servlet-class>

<init-param>

<param-name>driverClass</param-name>

<param-value>com.mysql.jdbc.Driver</param-value>

</init-param>

<init-param>

<param-name>conStr</param-name>

<param-value>jdbc:mysql://localhost:3306/stu</param-value>

</init-param>

</servlet>

<servlet-name>LogoutServlet</servlet-name>

<servlet-class>nkpack.LogoutServlet</servlet-class>

</servlet>

<servlet-name>ViewServlet</servlet-name>

<servlet-class>nkpack.ViewServlet</servlet-class>

</servlet>

<servlet-name>HitSpecifier</servlet-name>

<servlet-class>nkpack.HitSpecifier</servlet-class>

<init-param>

<param-name>driverClass</param-name>

<param-value>com.mysql.jdbc.Driver</param-value>

</init-param>

<init-param>

<param-name>conStr</param-name>

<param-value>jdbc:mysql://localhost:3306/stu</param-value>

</init-param>

</servlet>

<servlet-mapping>

<servlet-name>LoginServlet</servlet-name>

<url-pattern>/LoginServlet</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>LogoutServlet</servlet-name>

<url-pattern>/LogoutServlet</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>ViewServlet</servlet-name>

<url-pattern>/ViewServlet</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>HitSpecifier</servlet-name>

<url-pattern>/HitSpecifier</url-pattern>

</servlet-mapping>

<session-config>

<session-timeout>

</session-timeout>

</session-config>

<welcome-file-list>

<welcome-file>index.html</welcome-file>

</welcome-file-list>

</web-app>

Note: I have two table login and logintime
login
========
uname varchar
upass varchar

logintime
========
uname varchar
time time

Java Guru

Hit Counter for a Web site, time of hitting and no. of current users

No comments:

Post a Comment