null values getting in servlet using request.getParameter from jsp

Question

I have a jsp form as below,

<form action="../Registration" enctype="multipart/form-data">
    <label> First Name:</label>
    <input type="text" class="large-field" name="firstname">

    <label> Last Name:</label>
    <input type="text" class="large-field" name="lastname">

    <label> Gender:</label>
    <label class="radio">
    <input type="radio" name="gender"  value="Male">
        Male
    </label>
    <label class="radio">
    <input type="radio" name="gender" value="Female">
        FeMale
    </label>


    <label> Address :</label>
    <input type="text" class="large-field" name="address">


    <label> City:</label>
    <input type="text" class="large-field" name="city">


    <label> College:</label>
    <select class="large-field" name="college">
    <option value=""> --- Please Select --- </option>
    <option value="XYZ">XYZ</option>

    </select>

    <label> Branch:</label>
    <select class="large-field" name="branch">
        <option value=""> --- Please Select --- </option>
        <option value="ABC">ABC</option>
    </select>
    <br />
    <label> Mobile Number:</label>
    <input type="text" class="large-field" name="mobilenumber">
    <br />

    <label> Email_ID:</label>
    <input type="text" class="large-field" name="email">
    <br />
    <label> Password:</label>
    <input type="password" class="large-field"  name="password">
    <br />
    <label> Re-Enter Password:</label>
    <input type="password" class="large-field"  name="repassword">
    <br />
    <label> Profile Picture:</label>
    <input type="file" name="file">
    <br />

    <button class="btn btn-primary">Continue</button>
</form>

Then this calls my servlet which is coded as below:

package Client_Controller;

import CommonData.ComData;

import java.io.File;
import java.io.FileInputStream;
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 org.apache.tomcat.util.http.fileupload.FileItemFactory;
import org.apache.tomcat.util.http.fileupload.disk.DiskFileItemFactory;
import org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload;

import java.util.*;
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.RequestDispatcher;

import org.apache.tomcat.util.http.fileupload.FileItem;
import org.apache.tomcat.util.http.fileupload.FileUploadException;


public class Registration extends HttpServlet {

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        try {

            String f_name = request.getParameter("firstname");
            String l_name = request.getParameter("lastname");
            String gender = request.getParameter("gender");
            String address = request.getParameter("address");
            String city = request.getParameter("city");
            String college = request.getParameter("college");
            String branch = request.getParameter("branch");
            String mobile = request.getParameter("mobilenumber");
            String email = request.getParameter("email");
            String password = request.getParameter("password");
            String filePath = request.getParameter("file").toString();

            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/table", "root", "root");
            s = con.createStatement();
            s.execute("insert into tblmembers(first_name,last_name,sex,address,city,college_name,branch,mobile,email_id,password) " +
                    "values('" + f_name + "','" + l_name + "','" + gender + "','" + address + "','" + city + "','" + college + "','" + branch + "','" + mobile + "'," + email + ",'" + password + "')");

            out.write("Suceess");
        } catch (Exception e) {
            out.write("" + e);
        } finally {
            out.close();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">

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

        processRequest(request, response);
    }


    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        processRequest(request, response);
    }


    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}

When data is inserted all values are getting null. I have tried lots of things but not working so need some help. I using bootstrap as front end.

Answer 1

When using enctype="multipart/form-data" you cannot retrieve parameters using plain request.getParameter. Looks like you're using Servlet 2.5 or prior, so you need to parse the request using a third party library that process it by knowing the enctype. This can be easily done using Apache Common FileUpload library.

Note that this problem should not arise if using Servlet 3.0 or newer.

More info:

• How to upload files to server using JSP/Servlet?

Also, you have to add method="POST" to your current form to make it work. You cannot upload files using GET request.

Answer 2

Don't know why but it worked for me when I provided 'name' attribute to input text.

My Old code which returned null in Servlet:

<input id="closure" type="text" size="25"><a
                        href="javascript:NewCal('closure','ddmmyyyy')"><img
                            src="drawables/cal.gif" width="16" height="16" border="0"
                            alt="Pick a date"></a>

Just putting name="closure" worked for me. Now it perfectly returns value of this input text into servlet.

<input id="closure" name="closure" type="text" size="25"><a
                        href="javascript:NewCal('closure','ddmmyyyy')"><img
                            src="drawables/cal.gif" width="16" height="16" border="0"
                            alt="Pick a date"></a>

And I am getting value of this input text in Servlet as follows:

String closure = request.getParameter("closure");

Answer 3

use below one to access file data

  public static Hashtable getParamsFromMultipartForm(HttpServletRequest req) throws FileUploadException {
        Hashtable ret = new Hashtable();
        List items = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(req);
        for (FileItem item : items) {
            if (item.isFormField()) {
                ret.put(item.getFieldName(), item.getString());
            }
        }
        return ret;
    }

And then, whenever i need the value of any of my params, just write as below

/at the beginning of a servlet

Hashtable multipartParams = TheClassWhereIPutThatMethod.getParamsFromMultipartForm(req);


String myParamFromForm = multipartParams.get("myParamFromForm");

Answer 4

Change the following button to type submit and try again. My guess is your button is not submitting the form.

<button type="submit" class="btn btn-primary">Continue</button>