java servlet: doPost is called but not doGet

Question

I have a logging servlet called LoggingServlet and it overrides the doGet and doPost method as follows:

public class LoggingServlet extends HttpServlet {
    private static final long serialVersionUID = 2L;

    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        ...do stuff here
    }

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        ...do stuff here
    }

And my web.xml looks something like this:

  <servlet>
    <servlet-name>LoggingServlet</servlet-name>
    <servlet-class>com.example.servlets.LoggingServlet</servlet-class>
  </servlet>    

  <servlet-mapping>
    <servlet-name>LoggingServlet</servlet-name>
    <url-pattern>/LoggingServlet/*</url-pattern>
  </servlet-mapping>

And this is a snippet of a jsp that implements some JavaScript:

<script>
    document.getElementById("ad_div").onmousedown = function () {
        xmlhttp=new XMLHttpRequest();
        xmlhttp.open("GET","/LoggingServlet?bookie_id=<%= request.getParameter("id") %>&app_id=<%= request.getParameter("app_id") %>",true);
        xmlhttp.send();
        return true;
    };
</script>

I also have another jsp that calls the LoggingServlet via a Post request. Now my problem:

The Post request works fine without any problems
However the Get request from the javascript returns a 404 error. I also manually entered the complete url into the webbrowser and I got a 404 error.

How is that possible?

What URL did you enter in the browser window? Which URL did you use to fire the `POST` request? — Sanjay T. Sharma, Jun 30 '13 at 17:03
I don't see anything incorrect. Try to open the servlet path from a browser (this will invoke `doGet()`). — Konstantin Yovkov, Jun 30 '13 at 17:03
The current JS code assumes that the webapp is deployed to context root. Is this true? If not, then that explains you root problem. — BalusC, Jun 30 '13 at 17:05
@BalusC: That's it. The context was simply wrong. Thx for your answer. Give me an full answer and I will accept it. — toom, Jun 30 '13 at 17:46

score 6 · Accepted Answer · answered Jun 30 '13 at 17:09

The servlet is mapped to

/LoggingServlet/*

Your URL is

/LoggingServlet?bookie_id...

The URL thus lacks a trailing slash before the query string to be mapped to the servlet. It would need to be

/LoggingServlet/?bookie_id...

This would also only work if the webapp is the root webapp. If it isn't, you also need to prepend the context path of the application:

/MyWebApp/LoggingServlet/?bookie_id...

java servlet: doPost is called but not doGet

1 Answers1