Develop a simple servlet program which maintains a counter for the number of times it has been accessed since its loading, initialize the counter using deployment descriptor.

4. Servlet

4.1 Develop a simple servlet program which maintains a counter for the number of times it has been accessed since its loading, initialize the counter using deployment descriptor.

HitCounter.java

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HitCounter extends HttpServlet
{
    int c;
    public void init()
    {
        ServletConfig s=getServletConfig();
        c=Integer.parseInt(s.getInitParameter("counter"));
    }
    public void doGet(HttpServletRequest req, HttpServletResponse res)throws ServletException, IOException
    {
        c++;
        PrintWriter out = res.getWriter();
        out.println("Total Hit: " + c);
    }
}

web.xml

<servlet>
    <servlet-name>pagecounter</servlet-name>
    <servlet-class>HitCounter</servlet-class>
    <init-param>
        <param-name>counter</param-name>
        <param-value>0</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>pagecounter</servlet-name>
    <url-pattern>/counter</url-pattern>
</servlet-mapping>

Output

Happy Coding :)