How to send Form field values as session from jsp to servlet

Question

I have created the project for hospital management.. I want to send the form field values from jsp to servlet as session... I have tried the following code

Jsp page:

 

    
    Add patient details




    


         
              Patient details 
 


            
                

                    <%

                        try {
                            String name, age, gender, cat, time, token;
                            name = (String) request.getAttribute("name");
                            age = request.getParameter("age");
                            gender = request.getParameter("gender");
                            cat = request.getParameter("cat");
                            time = request.getParameter("time");
                            token = request.getParameter("token");

                            request.getSession().setAttribute("name", name);
                            request.getSession(true).setAttribute("name", name); // firstway

                            session.setAttribute("name", name); //another way
                            session.setAttribute("age", age);
                            session.setAttribute("gender", gender);
                            session.setAttribute("cat", cat);
                            session.setAttribute("time", time);
                            session.setAttribute("token", token);
                            out.println("Session " + request.getSession().getAttribute("name").toString());
                        } catch (Exception e) {
                            out.println("The exception part is " + e);
                        }

                    %>

                 


                            Patient's name:   



                            Patient's age:   

                   

                            Gender :  male  
                            female 

  
                            Category of doctor to meet:  

   
                            Visiting time:  
 


                            Your token number:

Servlet page:

package Patientdetails;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.jms.Session;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class Patientdetails extends HttpServlet {

HttpServletRequest request;
String[] pname = {"name", "age", "gender", "cat", "time", "token"};
String[] pvalue = new String[6];

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
    try {
        out.println("");
        out.println("");
        out.println("");
        // out.println(""+session.getAttribute("name")+"");            
        out.println("");
        out.println("");


    } finally {
        out.close();
    }
}

@Override
public void init() {

}

@Override
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {

    PrintWriter out = response.getWriter();


    try {
        for (int i = 0; i < pname.length; i++) {
            pvalue[i] = (String) request.getSession().getAttribute(pname[i]);


        }



        out.println("");

        out.println("");
            out.println("The Session value is " + request.getSession().getAttribute("name")+"");
        out.println("");
        out.println("");
    } catch (Exception e) {
        out.println("Exception part " + e);
        e.printStackTrace(out);
    }
}

@Override
public void destroy() {
}
}
When i try like this, Iam just getting null value in servlet page.. I don't know why it just passing null values?? Is there any other methods to pass values as session???
Patient Name Patient Age Gender Category of doctor Appointment Time Token no
" + pvalue[0] + "  " + pvalue[1] + " " + pvalue[2] + " " + pvalue[3] + "  " + pvalue[4] + "  " + pvalue[5] + "

John Topley · Accepted Answer

You need to keep clear in your mind which code is executing client-side in the browser and which is executing server-side. At the point at which the scriptlet code executes in your JSP, your HTML form hasn't been submitted yet, so there are no form values stored in the request or session objects. That's why the form field values are null.

You should move the code to retrieve the field values from your submitted form to the servlet, as that's where the form submits to (as specified by its action attribute). To get the form values from within your servlet, you can use:

String paramValue = request.getParameter("paramName");

To retrieve a value from the HTTP session, use:

request.getSession().getAttribute("attributeName");

You wouldn't typically retrieve the parameter values from the request for the purposes of storing them in the session. It's cleaner to make the JSP session-scoped to begin with.

As an aside, note that your HTML form should use the HTTP POST method rather than GET if it can't safely be submitted more than once (usually because it's changing some server-side state).

How to send Form field values as session from jsp to servlet

Answers (1)

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