connection to the URL fails but when I directly try in the browser, it succeeds

Question

The following snippet tries to send 2 parameters along with a URL to a servlet. But when I try this snippet,I get a message :

Connection to file server failed

But if I directly try the URL :

http://localhost:8084/nappster/ReceiveFileName?fileName=" + fileName + "&ip=" + IP

with the data, there is no problem. Servlet receives the file name and processes it as expected. What could be the reason that when I try to connect to the URL via code, it fails and succeeds when trying in a browser.

  protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    String fileName = request.getParameter("FileTag");
    String IP = new ClientAddress().getNetworkIP();                
    // Send the file name to the nappster server 
    URL url = new URL("http://localhost:8084/nappster/ReceiveFileName?fileName=" + fileName + "&ip=" + IP);
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    if(connection.getResponseCode() == 200) {
        // File name sent successfully to the server
        System.out.println("Connection to file server successful");
        System.out.println("--------");
    } else {
        // Unable to send file name to the server
        System.out.println("Connection to file server failed");

     }
}

NOTE :

Response code returned when I try the above snippet is 505

can you print the value of `connection.getResponseCode()` when you get your response code ? — Majid Laissi, Jan 04 '13 at 14:52
That is HTTP version not supported... I think HttpUrlConnection is v1.0 only, you might want to try something like HttpComponents (http://hc.apache.org/) instead - the server may require 1.1. — cjstehno, Jan 04 '13 at 15:07
@cjstehno but when I am trying in another servlets it works fine. For example `http://localhost:8084/nappster/ReceiveInformation?" + information` — saplingPro, Jan 04 '13 at 15:14
There might be redirect which you do not notice in your browser - try to print more data instead of just System.out.println("Connection to file server failed"); — Hurda, Jan 04 '13 at 14:51

score 1 · Answer 1 · answered Jan 04 '13 at 15:01

1

Try using url.encode() method.

answered Jan 04 '13 at 15:01

Mukund K Roy

175
1
8

The information you are passing may contain alphabetic characters, numerals, and a few special characters that have meaning in the URL string. So to avoid that we use encoding. please check whether your filename or ip parameter has any of these. – Mukund K Roy Jan 04 '13 at 15:10
but then I can directly access the URL in the browser. How is that ? – saplingPro Jan 04 '13 at 15:15
Browsers encode urls by default before posting to the servers. – Mukund K Roy Jan 04 '13 at 15:22
Please share the actual URL and the reponsecode you are getting now – Mukund K Roy Jan 04 '13 at 15:43
See http://stackoverflow.com/questions/10786042/java-url-encoding for an example on how to correctly encode a URL using URLEncoder – Gustav Grusell Jan 04 '13 at 15:46
With it or without it, now I am getting _200_ ! – saplingPro Jan 04 '13 at 16:03

connection to the URL fails but when I directly try in the browser, it succeeds

1 Answers1