This example illustrates about counting how many times the servlet is
accessed. When first time
servlet (
CounterServlet) runs then session is created and value of the counter will be zero and after
again accessing of servlet the counter value will be increased by one. In this
program
isNew() method is used whether session is new or old and
getValue()
method is used to get the value of counter.
Here is the source code of CounterServlet.java:
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class CounterServlet extends HttpServlet{
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(true);
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Integer count = new Integer(0);
String head;
if (session.isNew()) {
head = "This is the New Session";
} else {
head = "This is the old Session";
Integer oldcount =(Integer)session.getValue("count");
if (oldcount != null) {
count = new Integer(oldcount.intValue() + 1);
}
}
session.putValue("count", count);
out.println("<HTML><BODY BGCOLOR=\"#FDF5E6\">\n" +
"<H2 ALIGN=\"CENTER\">" + head + "</H2>\n" +
"<TABLE BORDER=1 ALIGN=CENTER>\n"
+ "<TR BGCOLOR=\"#FFAD00\">\n"
+" <TH>Information Type<TH>Session Count\n"
+"<TR>\n" +" <TD>Total Session Accesses\n" +
"<TD>" + count + "\n" +
"</TABLE>\n"
+"</BODY></HTML>" );
}
}
|
Mapping of Servlet ("CounterServlet.java") in web.xml file
<servlet>
<servlet-name>CounterServlet</servlet-name>
<servlet-class>CounterServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CounterServlet</servlet-name>
<url-pattern>/CounterServlet</url-pattern>
</servlet-mapping> |
Running the servlet by this url: http://localhost:8080/CodingDiaryExample/CounterServlet
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