Writing to a URLConnection question

Question

Hi, I have the following issue hope someone can help!
Thank you in advcance!
Eric
Program Goal
- Want to write a program that logs in to a website that requires a username and password.
- The actual URL of the page I want to login:
     http://www.19lou.com/passportlogin.php?action=login
What I have done
- I followed the Sun Java Networking Tutorial and wrote the program. Below are the steps:
1. Create a URL.
2. Retrieve the URLConnection object.
3. Set output capability on the URLConnection.
4. Open a connection to the resource.
5. Get an output stream from the connection.
6. Write to the output stream.
7. Close the output stream.
Problem
- I wrote my program and printed the server's response. It says invalid login or password. When I manually
logon, the username and password work correctly.
- I suspect that the content line my program HTTP POST to the server is incorrect.
- Here is segment of my code:
     private static final String POST_CONTENT_TYPE = "application/x-www-form-urlencoded";
     private static final String LOGIN_ACTION_NAME = "login";
     private static final String LOGIN_USER_NAME = "test";
     private static final String LOGIN_PASSWORD = "test";
     private static final String TARGET_URL = "http://www.19lou.com/passportlogin.php?action=login";
     //Encode the content to be POSTED
     private String preparePostContent(String loginUserName, String loginPassword) throws UnsupportedEncodingException {
          //Encode username and password to UTF-8 encoding standard
          String encodedLoginUserName = URLEncoder.encode(loginUserName, "UTF-8");
          String encodedLoginPassword = URLEncoder.encode(loginPassword, "UTF-8");
          String content = "login=" + encodedLoginUserName + "&password=" + encodedLoginPassword;
          return content;
     //HTTP POST code
     public HttpURLConnection doHttpPost(String targetUrl, String content) throws IOException {
          HttpURLConnection urlConn = null;
          DataOutputStream dos = null;
          try {
               //Open a connection to the target URL
               URL aUrl = new URL(targetUrl);
               urlConn = (HttpURLConnection)aUrl.openConnection();
               //Specify that we intend to use this connection for input and output
               urlConn.setDoInput(true);
               urlConn.setDoOutput(true);
               //Specify the content type of our post
               urlConn.setRequestProperty("Content-Type", POST_CONTENT_TYPE);
               //Specify the method of HTTP request which is POST
               //throws ProtocolException
               urlConn.setRequestMethod("POST");
               //Prepare an output stream for writing data to the HTTP connection
               //throws IOException
               OutputStream os = urlConn.getOutputStream();
               dos = new DataOutputStream(os);
               //Writing data
               //throws IOException
               dos.writeBytes(content);
               dos.flush();
               dos.close();
               return urlConn;
          catch(IOException e) {
Questions
1. Is anything wrong with the content line that's causing the program not being able to login?
     String content = "login=" + encodedLoginUserName + "&password=" + encodedLoginPassword;
2. Any other parameter that's missing?
3. The keys here are "login" and "password". Are they the same for every system, even a different language?

Answer 1

This is a complicated thing. I have used apache's httpclient and ftpclient in the past to circumvent this. The problem is that it then takes you away from URL + URLConnection. Also, I'm not sure you can do SSL with that.
I recommend you look around the web. I found some good examples of how to do CGI when I was trying to do this.