Sending post data from JSP to a Java Servlet

Question

I am trying to send data from a JSP file to a Java Servlet. I've seen so many examples on here on how to do it, and I believe I am doing it the right way, but for some reason the doPost() methods is not being called inside my servlet.

Here is what I added to my web.xml file:

<?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>loginServlet</servlet-name>
    <servlet-class>src.action.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>loginServlet</servlet-name>
    <url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>

Here is my JSP file

    <html>
    <head>

    </head>

    <body>

        <form action = "localhost:8080/UserModule/src/action/login" method="post">
            Username<input type = "text" name = "username"><br><br>
            Password<input type = "password" name = "password"><br><br>
            <input type = "submit" value = "Submit">
        </form>
    </body> 
</html>

Here is my Java servlet:

   package action;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public LoginServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        String username = (request.getAttribute("username")).toString();
        System.out.println("asd");

        String password = (String) request.getAttribute("password");
        System.out.println(username);
    }

}

It's giving me an error on import javax.servlet.annotation.WebServlet; and on @WebServlet("/login")

It's because they were only implemented in the spec v3.0, while I am only allowed to use spec v2.5 (required to at work). Anyone has any idea how to solve this issue?

My directory:

enter image description here

here is your [Ref](http://stackoverflow.com/questions/4971877/how-to-transfer-data-from-jsp-to-servlet) u get all the important information from given link — Parth Akbari, Nov 18 '14 at 12:48

Santhosh · Answer 1 · 2014-11-18T12:48:25.190

2

I could see multiple errors in your post ,

Replace the action attribute with ,

<form action = "./login" method="post">
If your using the version 2.5 , remove the import for annotation and also this line,

@WebServlet("/login")
Thirdly, to access the <form> elements in the servlet , use request#getParameter

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

edited Nov 18 '14 at 12:48

answered Nov 18 '14 at 12:42

Santhosh

8,181
4
29
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When I do
it redirects to localhost:8080/UserModule/WebContent/jsp/login which doesn't exist. My Servlet is in the same project, but under a different directory and package.
– Obviously Nov 18 '14 at 12:52
@Obviously use a `./login` in the action attribute – Santhosh Nov 18 '14 at 12:54
I did set ./login in the action attribute like this: `
`
– Obviously Nov 18 '14 at 12:57
is this valid path `src.action.LoginServlet` of your servlet . post your directory structure in your question – Santhosh Nov 18 '14 at 12:58
I fixed this issue. It's still not working. Anyway, I posted my directory structure in my question. Thanks. – Obviously Nov 18 '14 at 13:04
@Obviously Can you add the pic here . restricted site for my network – Santhosh Nov 18 '14 at 13:11
I would, but it doesn't let me because I have less than 10 reputation. – Obviously Nov 18 '14 at 13:12
where have you placed your servlet in the project ? And what error you are getting now ? is that 404 ?> – Santhosh Nov 18 '14 at 13:14
UserModule is my project. I have a folder called src under it, with four packages under that named action, bo, dao, and vo. My servlet is inside action. I have another folder under UserModule called jsp, with my jsp file in it. WEB-INF is also under UserModule, and it has web.xml in it. `
` redirects to localhost:8080/login which is a 404. login is in src/action
– Obviously Nov 18 '14 at 13:15
so it is enough to declare as `action.LoginServlet` in your `web.xml` and it will find the required servlet – Santhosh Nov 18 '14 at 13:17

score 0 · Answer 2 · edited May 23 '17 at 12:12

0

Your class is in package action so its full name is action.LoginServlet. You have configured src.action.LoginServlet as the servlet class. Remove src from there.

<servlet>
    <servlet-name>loginServlet</servlet-name>
    <servlet-class>action.LoginServlet</servlet-class>
</servlet>

This part:

<form action = "localhost:8080/UserModule/src/action/login" method="post">

You have lot of boilerplate code there. Instead, use Expression Language to add localhost:8080/webappName like this:

<form action = "${request.contextPath}/login" method="post">

Since you're using Servlet Specification 2.5, you cannot use @WebServlet annotation. So remove it from your Serlvet class. Otherwise, start using Servlet 3.0 or superior by changing the servlet specification in your web.xml

To retrieve parameters from the submitted <form> use ServletRequest#getParameter. request#getAttribute is used in JSP to retrieve attributes to display the data when using Expression Language.

edited May 23 '17 at 12:12

Community

1
1

answered Nov 18 '14 at 12:43

Luiggi Mendoza

85,076
16
154
332

this only redirected to localhost:8080/login which doesn't exist – Obviously Nov 18 '14 at 12:54
@Obviously then there's something wrong in your application. I have used it several times and works as expected. – Luiggi Mendoza Nov 18 '14 at 12:56
@Obviously please provide info about how you're deploying your web app and what's the distribution of the files. – Luiggi Mendoza Nov 18 '14 at 12:59
I guess. But even when it was hardcoded, and I used `ServletRequest#getParameter` and fixed all the other issues you mentioned, it still doesn't work unfortunately. – Obviously Nov 18 '14 at 13:00
@Obviously have you done all the changes I posted here or just a mix of changes based on all the answers? – Luiggi Mendoza Nov 18 '14 at 13:02
I did all the changesyou mentioned here. Also, I posted an image of my directory and distribution. – Obviously Nov 18 '14 at 13:05
@Obviously please post your web.xml as well. – Luiggi Mendoza Nov 18 '14 at 13:23
It is already posted minus this: – Obviously Nov 18 '14 at 13:23
Again: post your entire web.xml file in your question. Something's very odd within your project and we don't jave enough info to find that problem – Luiggi Mendoza Nov 18 '14 at 13:24

score 0 · Answer 3 · answered Nov 18 '14 at 12:46

0

Just remove @WebServlet("/login")

This annotation and servlet mapping are interchangeable. So when you use one of these another definition is not required.

In order to use @WebServlet webapp's web.xml has to be declared as version 3.0

<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_3_0.xsd"
    version="3.0">

answered Nov 18 '14 at 12:46

Oleh Novikov

558
5
17

I know, but I am required to use version 2.5 – Obviously Nov 18 '14 at 12:50
Then `@WebServlet` will not work for you. Stick to the servlet mappings inside of your web.xml and also as said by @luiggi-mendoza consider replacig hardcoded localhost:8080 with ${request.contextPath} – Oleh Novikov Nov 18 '14 at 12:55
As I mentioned under @luiggi-Mendoza's post,
only redirected to localhost:8080/login which doesn't exist
– Obviously Nov 18 '14 at 12:56

Sending post data from JSP to a Java Servlet

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