Java Servlet HttpServletRequest parameters showing up as null

Question

I am trying to get form parameters from a GET request. The html code is below.

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>DesignMatch. Matching the best clients and best designers.</title>
        <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
        <script type="text/javascript" src="jquery.backstretch.js"></script>
        <script type="text/javascript" src="design_match.js"></script>
        <link rel="stylesheet" type="text/css" media="all" href="design_match.css" />
    </head>
    <body>
        <div id="matte_bg"></div>
        <div id="entire_wrapper">
            <div class="divModule" id="section_head_1">
                <p class="primaryPageText">
                    Clients
                </p>
                <div class="url-bar">
                    <form name="clientUrls" action="SaveDatabase2" target="_blank" method="get">
                        <input type="text" class="url-box" id="url-box1" name="name1" size="20" value="Paste a link to a website that has the design qualities you want.">
                        <a id="add-url" href="#">Add</a>
                        <a id="del-url" href="#">Remove</a>
                    </form>
                </div>
            </div>
            <div class="divModule" id="section_head_2">
                <p class="primaryPageText">
                    Designers
                </p>
                <div class="portfolio-bar">
                    <form name="designerUrls" action="SaveDatabase2" target="_blank" method="get">
                        <input type="text" class="portfolio-box" id="portfolio-box1" name="name1" size="20" value="Paste a link to a website you designed.">
                        <a id="add-portfolio" href="#">Add</a>
                        <a id="del-portfolio" href="#">Remove</a>
                    </form>
                </div>
            </div>
            <div class="divModule">
                <div class="filterSentence">
                    <ul class="primaryPageText">
                        <li>
                            &nbsp; To me, &nbsp;
                        </li>
                        <li class="budgetTypeFilter">
                            <a href="#" id="budgetToggle">[what price]</a>
                            <div id='budgetFilter' style="display:none" class="budgetTypeMenu">
                                <a href="/500-under">$500 and under</a>
                                <a href="/500-to-1000">$500-$1,000</a>
                                <a href="/1000-to-2500">$1,000-$2,500</a>
                                <a href="/2500-to-5000">$2,500-$5,000</a>
                                <a href="/5000-to-7500">$5,000-$7,500</a>
                                <a href="/7500-to-10000">$7,500-$10,000</a>
                                <a href="/10000-above">Over $10,000</a>
                            </div>
                        </li>
                        <li>
                            &nbsp; seems fair to pay for &nbsp;
                        </li>
                        <li class="budgetTypeFilter">
                            <a href="#" id="typeToggle">[what type of]</a>
                            <div id='typeFilter' style="display:none" class="budgetTypeMenu">
                                <a href="/basic">a basic (e.g., front-end only)</a>
                                <a href="/dynamic">a dynamic (e.g., a little back-end)</a>
                                <a href="/sophisticated">a sophisticated (e.g., lots of back-end)</a>
                            </div>
                        </li>
                        <li>
                            &nbsp; website. &nbsp;
                        </li>
                    </ul>
                </div>
            </div>
            <div class="divModule contact-bar" id="contact">
                <form name="nameForm" action="SaveDatabase2" target="_blank" method="get">
                    <input type="text" id="name_form" name="name_form" size="20" value="Tell us your name.">
                </form>
                <form name="contactForm" action="SaveDatabase2" target="_blank" method="get">
                    <input type="text" id="contact_form" name="contact_form" size="20" value="Enter your e-mail (no spam, ever).">
                </form>
            </div>
            <div id="submit">
                <form accept-charset="UTF-8" action="SaveDatabase2" method="get">
                    <input class="btn primary large" id="submit-button" name="submit" type="submit" value="✔" />
                </form>
            </div>
        </div>
    </body>
</html>

Here is the Servlet code. The parameter values I get in doPost are null. I tried changing all the get requests to post in the html and it didn't help. The doGet function is just rerouted to doPost. The two main parameters I am interested in right now are the "contact_form" and "name_form" parameters at the end of the html. Thanks again!

package web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.mysql.jdbc.StringUtils;
import java.sql.*;
import java.io.*;
import java.util.*;

/**
 * Servlet implementation class SaveDatabase2
 */
public class SaveDatabase2 extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public SaveDatabase2() {
        super();
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doPost(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<h1> Thank You </h1>");

        //Get Info for Database     
        int designer=0;
        String clientType="";
        String name= "";
        String email="";
        //Get parameters to put into database
        Enumeration parameterNames = request.getParameterNames();
        if ((request.getParameter("designerUrls")!=null) && !request.getParameter("designerUrls").matches(".*\\w.*") ){
            designer=1;
        }
        if (designer==1){
            clientType="designer";
        }else clientType="client";

        name= request.getParameter("name_form");
        email=request.getParameter("contact_form");

}

Why do you have so many <form> tags? You should just have all input fields inside just one form tag. — Manish
– Manish, Commented Jan 3, 2012 at 10:08
Thanks a lot. Someone else did the front end so I was trying to hook it up to the back end so I just assumed there was nothing wrong with the html. I'm going to change it to one form and see if it works — Timnit Gebru
– Timnit Gebru, Commented Jan 3, 2012 at 10:20

Mr.J4mes · Accepted Answer · 2012-01-03 10:06:31Z

3

First of all, I think you should leave doPost and doGet as 2 different methods. doPost will automatically be triggered if you set the attribute method of your form to post.

Besides, your form should be like this:

<form name="myForm" accept-charset="UTF-8" action="SaveDatabase2" target="_blank" method="post">
   <input type="text" id="name_form" name="name_form" size="20" value="Tell us your name.">
   <input type="text" id="contact_form" name="contact_form" size="20" value="Enter your e-mail (no spam, ever).">
   <input class="btn primary large" id="submit-button" name="submit" type="submit" value="✔" />
</form>

In your question, the submit button is in its own form which does not contain the 2 input text fields: name_form and contact_form. That's why you got the null values.

answered Jan 3, 2012 at 10:06

Mr.J4mes

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1 Comment

Timnit Gebru Over a year ago

thanks so much for your prompt reply. I'll make those changes on the form

Community · Accepted Answer · 2017-05-23 11:55:32Z

0

I think you are misunderstanding the <form> element. To send data from the page to the servlet you can use method="get" or method="post" - both still send the data one way (client to server). For the difference see When do you use POST and when do you use GET?

The <form> can encompass many <input>s and but the crucial part that is missing from your code is that the <form> that is submitting (the one with the <input type="submit"/>) does not contain any of the <input> elements you are expecting. They are in other <form>s which are not submitted. Only the <form> that contains the submit button is submitted.

You should use one <form> around all your fields and submit button.

edited May 23, 2017 at 11:55

CommunityBot

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answered Jan 3, 2012 at 10:21

andyb

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