Hidden field in Servlet

Satyapriya Nayak
13y
7.4k
0
1

Article

Hidden field:

This is a process to store information present in the current request in a form field called a hidden field. Whenever a form containing a hidden field gets submitted then the destination servlet can find the value of the hidden field by using the getParameter() method of the request.

Example: - Servlet to accept name of the user as first name and last name and showing the full name using a hidden field.

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class hidden extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)throws IOException,ServletException
{
String s1=req.getParameter("t1");
String s2=req.getParameter("t2");
PrintWriter out=res.getWriter();
out.println("<html><body>");
if(s1 ==null)
{
out.println("<form>");
out.println("<h1>FName<input type='text' name='t1'></h1>");
out.println("<input type='submit' value='submit'>");
out.println("</form>");
}
else if(s2 ==null)
{
out.println("<form>");
out.println("<h1>LName<input type='text' name='t2'></h1>");
out.println("<input type='hidden' name='t1' value='"+s1+"'>");
out.println("<input type='submit' value='submit'>");
out.println("</form>");
}
else
{
out.println("<h1>Welcome "+s1+" "+s2+"</h1>");
}
out.println("</body></html>");
}
}

Web.xml settings

<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app 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"
version="2.5">

<servlet>
<servlet-name>hidden</servlet-name>
<servlet-class>hidden</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>hidden</servlet-name>
<url-pattern>/hidden</url-pattern>
</servlet-mapping>

</web-app>

Compile

javac -cp servlet-api.jar hidden.java (for tomcat 6.0)

Hidden field in Servlet

Running in web-browser

Run the tomcat then write the below line in the URL
Here test is the Context path, which we mentioned in the server.xml file, which is present in (E:\Program Files\Apache Software Foundation\Tomcat 6.0\conf) directory.

http://localhost: 8081/test/hidden

Hidden field in Servlet

Thanks for reading.

Up Next

Ebook Download

View all

Frontend Developer Interview

Read by 3 people

Download Now!

Learn

View all