Getting null While Passing String from jsp to servlet

Question

This is my Jsp File

<body>
<% 
    URL url = new    
            URL("http://localhost:8080/ServletToCloud/JSPToServletToCloudServlet");
    URLConnection conn =url.openConnection();
            conn.setDoOutput(true);

    BufferedWriter bw= new BufferedWriter( new OutputStreamWriter( 
            conn.getOutputStream() ) );
    bw.write("username= Shanx");
            out.flush();
            out.close();
    %>
</body>

This is my servlet class

   @SuppressWarnings("serial")
   public class JSPToServletToCloudServlet extends HttpServlet 
   {
    private final static String _USERNAME = "username";
    protected void doGet(HttpServletRequest request, HttpServletResponse response)   
        throws ServletException, IOException 
        {
    PrintWriter out = response.getWriter();
            String username = request.getParameter(_USERNAME);

            response.setContentType("text/html");
            out.println("HelloWorld");
            out.println("Hello " + username);
            out.close();
    }

This is the web.xml file

  <servlet>
    <servlet-name>JSPToServletToCloud</servlet-name>
    <servlet-class>pack.exp.JSPToServletToCloudServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>JSPToServletToCloud</servlet-name>
    <url-pattern>/jsptoservlettocloud</url-pattern>
</servlet-mapping>
<welcome-file-list>
    <welcome-file>index.html</welcome-file>
</welcome-file-list>
 </web-app>

My Jsp File is in Dynamic Web Application and is sending a string to Servlet which is in Web application Project. I am running the dynamic web application project on apache tomcat server and after the server is started I am running my web application projewct as web application and checking on local host and getting null.

Help me out guys.

Do you have a `doPost` method in your Servlet? Your JSP code should be making a POST request because of `conn.setDoOutput(true);`. — Sotirios Delimanolis, Feb 12 '14 at 07:18
[Here is a pretty good post][1] [1]: http://stackoverflow.com/questions/2793150/how-to-use-java-net-urlconnection-to-fire-and-handle-http-requests You should have searched first. Hope this helps — Sanjeev, Feb 12 '14 at 07:19
@ Sotirios Delimanolis yes I tried with doPost also it is giving null only — user3273473, Feb 12 '14 at 07:22
It is because you're never sending the `"username"` parameter in your request... — Luiggi Mendoza, Feb 12 '14 at 07:37
@ Luiggi Mendoza :for this i have to write "http://localhost:8080/ServletToCloud/JSPToServletToCloudServlet?username=abc" , after trying this still i m getting null value — user3273473, Feb 12 '14 at 08:20

score 1 · Answer 1 · answered Feb 12 '14 at 11:04

1

you will have to put username name wither in session, because you are not set the username in request.

put user name in session and on server Side write :-

 HttpSession session = request.getSession();
 String username = session.getAttribute("username")

answered Feb 12 '14 at 11:04

Mitul Maheshwari

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Getting null While Passing String from jsp to servlet

1 Answers1