How can i login to a website using java

Question

hi,
i tried to write a java program to which will take username and password and login to a given site. but some how its not working. i am actually trying to login to the follwoing website:
https://roundup.ffmpeg.org/roundup/ffmpeg/
can anyone provide some example program to login to this website.
br
mahbubul-syeed

Answer 1

Hi,
i am really sorry... but i am new in this forum and i did not know this. here is my code that i have written. it did not show any error and displays the content of the page but did not logged in. please give your comment.. i badly need a solution.
package myUtility_files;
import java.net.*;
import java.io.*;
public class LogInByHttpPost {
     //private static final String POST_CONTENT_TYPE = "application/x-www-form-urlencoded";
private static final String LOGIN_ACTION_NAME = "submit";
private static final String LOGIN_USER_NAME_PARAMETER_NAME = "__login_name";
private static final String LOGIN_PASSWORD_PARAMETER_NAME = "__login_password";
private static final String LOGIN_USER_NAME = "mahbubul";
private static final String LOGIN_PASSWORD = "mahbubul007";
private static final String TARGET_URL = "http://roundup.ffmpeg.org/roundup/ffmpeg/";
public static void main (String args[])
LogInByHttpPost httpUrlBasicAuthentication = new LogInByHttpPost();
httpUrlBasicAuthentication.httpPostLogin();
public void httpPostLogin ()
try
// Prepare the content to be written
// throws UnsupportedEncodingException
String urlEncodedContent = preparePostContent(LOGIN_USER_NAME, LOGIN_PASSWORD);
HttpURLConnection urlConnection = doHttpPost(TARGET_URL, urlEncodedContent);
//String response = readResponse(urlConnection);
System.out.println("Successfully made the HTPP POST.");
//System.out.println("Recevied response is: '/n" + response + "'");
BufferedReader in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
               String inputLine;
               while ((inputLine = in.readLine()) != null)
                    System.out.println(inputLine);
catch(IOException ioException)
     ioException.printStackTrace();
System.out.println("Problems encounterd.");
private String preparePostContent(String loginUserName, String loginPassword) throws UnsupportedEncodingException
// Encode the user name and password to UTF-8 encoding standard
// throws UnsupportedEncodingException
String encodedLoginUserName = URLEncoder.encode(loginUserName, "UTF-8");
String encodedLoginPassword = URLEncoder.encode(loginPassword, "UTF-8");
String content = "login=" + LOGIN_ACTION_NAME +" &" + LOGIN_USER_NAME_PARAMETER_NAME +"="
+ encodedLoginUserName + "&" + LOGIN_PASSWORD_PARAMETER_NAME + "=" + encodedLoginPassword;
return content;
public HttpURLConnection doHttpPost(String targetUrl, String content) throws IOException
HttpURLConnection urlConnection = null;
DataOutputStream dataOutputStream = null;
try
// Open a connection to the target URL
// throws IOException
urlConnection = (HttpURLConnection)(new URL(targetUrl).openConnection());
// Specifying that we intend to use this connection for input
urlConnection.setDoInput(true);
// Specifying that we intend to use this connection for output
urlConnection.setDoOutput(true);
// Specifying the content type of our post
//urlConnection.setRequestProperty("Content-Type", POST_CONTENT_TYPE);
// Specifying the method of HTTP request which is POST
// throws ProtocolException
urlConnection.setRequestMethod("POST");
// Prepare an output stream for writing data to the HTTP connection
// throws IOException
dataOutputStream = new DataOutputStream(urlConnection.getOutputStream());
// throws IOException
dataOutputStream.writeBytes(content);
dataOutputStream.flush();
dataOutputStream.close();
return urlConnection;
catch(IOException ioException)
System.out.println("I/O problems while trying to do a HTTP post.");
ioException.printStackTrace();
// Good practice: clean up the connections and streams
// to free up any resources if possible
if (dataOutputStream != null)
try
dataOutputStream.close();
catch(Throwable ignore)
// Cannot do anything about problems while
// trying to clean up. Just ignore
if (urlConnection != null)
urlConnection.disconnect();
// throw the exception so that the caller is aware that
// there was some problems
throw ioException;
br
mahbubul-syeed
Edited by: mahbubul-syeed on Jun 11, 2009 5:07 AM