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Thread: Login website using Java

  1. #1
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    Default Login website using Java

    I am trying to automate a login to a website and then navigate to a webpage and retrieve the html from the page. I found some examples of how to login, but am having difficulty figuring out how to navigate to another page once logged in. I've read some information about using cookies, but I haven't done much website programming and am not sure how to implement cookies into the code I've found. Any guidance would be appreciated

    import java.net.*;
    import java.io.*;
     
     
     
    public class WebsiteLogin {
     
    	 private static final String POST_CONTENT_TYPE = "application/x-www-form-urlencoded";
    	    private static final String LOGIN_USER_NAME_PARAMETER_NAME = "username";
    	    private static final String LOGIN_PASSWORD_PARAMETER_NAME = "password";
     
    	    private static final String LOGIN_USER_NAME = "myusername";
    	    private static final String LOGIN_PASSWORD = "mypass";
     
    	    private static final String TARGET_URL = "http://<mysite>.com/cgi-bin/member.cgi";
     
    	public static void main(String[] args)
    	{
            System.out.println("Running the program...\n");
            WebsiteLogin httpUrlBasicAuthentication = new WebsiteLogin();
            httpUrlBasicAuthentication.httpPostLogin();
     
    	}
     
    	   /**
         * The single public method of this class that
         * 1. Prepares a login message
         * 2. Makes the HTTP POST to the target URL
         * 3. Reads and returns the response
         *
         * @throws IOException
         * Any problems while doing the above.
         *
         */
        public void httpPostLogin ()
        {
            try
            {
                // Prepare the content to be written
                // throws UnsupportedEncodingException
                String urlEncodedContent = preparePostContent(LOGIN_USER_NAME, LOGIN_PASSWORD);
     
                System.out.println(urlEncodedContent);
                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 + "'");
     
            }
            catch(IOException ioException)
            {
                System.out.println("Problems encounterd.");
            }
        }
     
        /**
         * Using the given username and password, and using the static string variables, prepare
         * the login message. Note that the username and password will encoded to the
         * UTF-8 standard.
         *
         * @param loginUserName
         * The user name for login
         *
         * @param loginPassword
         * The password for login
         *
         * @return
         * The complete login message that can be HTTP Posted
         *
         * @throws UnsupportedEncodingException
         * Any problems during URL encoding
         */
        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;*/
     
            String content = LOGIN_USER_NAME_PARAMETER_NAME +"="
            + encodedLoginUserName + "&" + LOGIN_PASSWORD_PARAMETER_NAME + "=" + encodedLoginPassword;
     
            return content;
     
        }
     
        /**
         * Makes a HTTP POST to the target URL by using an HttpURLConnection.
         *
         * @param targetUrl
         * The URL to which the HTTP POST is made.
         *
         * @param content
         * The contents which will be POSTed to the target URL.
         *
         * @return
         * The open URLConnection which can be used to read any response.
         *
         * @throws IOException
         */
        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);
                urlConnection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8");
     
                HttpURLConnection.setFollowRedirects(true);
                // 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;
            }
        }
     
        /**
         * Read response from the URL connection
         *
         * @param urlConnection
         * The URLConncetion from which the response will be read
         *
         * @return
         * The response read from the URLConnection
         *
         * @throws IOException
         * When problems encountered during reading the response from the
         * URLConnection.
         */
        private String readResponse(HttpURLConnection urlConnection) throws IOException
        {
     
            BufferedReader bufferedReader = null;
            try
            {
                // Prepare a reader to read the response from the URLConnection
                // throws IOException
                bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                String responeLine;
     
                // Good Practice: Use StringBuilder in this case
                StringBuilder response = new StringBuilder();
     
                // Read until there is nothing left in the stream
                // throws IOException
                while ((responeLine = bufferedReader.readLine()) != null)
                {
                    response.append(responeLine);
                }
     
                return response.toString();
            }
            catch(IOException ioException)
            {
                System.out.println("Problems while reading the response");
                ioException.printStackTrace();
     
                // throw the exception so that the caller is aware that
                // there was some problems
                throw ioException;
     
            }
            finally
            {
                // Good practice: clean up the connections and streams
                // to free up any resources if possible
                if (bufferedReader != null)
                {
                    try
                    {
                        // throws IOException
                        bufferedReader.close();
                    }
                    catch(Throwable ignore)
                    {
                        // Cannot do much with exceptions doing clean up
                        // Ignoring all exceptions
                    }
                }
     
            }
        }
     
    }

    Web page code:

    <html>
    <head>
    	<title>Member Login</title>
     
    </head>
    <body>
    <form action="/cgi-bin/login.cgi" method=POST>
    	<input type="hidden" name="go" value="1">
    	<table>
    	<tr>
    		<td align=right valign=top>
    		<b>Username:</b>
    		</td>
    		<td align=left valign=top>
    		<input type="text" name="username">
    		</td>
    	</tr>
    	<tr>
    		<td align=right valign=top>
    		<b>Password:</b>
    		</td>
    		<td align=left valign=top>
    			<input type="password" name="password">
    		</td>
    	</tr>
    	<tr>
    		<td align=center valign=top colspan="2">
    			<input type="submit" value="Login">
    		</td>
    	</tr>
    	</table>
    </form>
    </body>
    </html>
    Last edited by cgeier; March 21st, 2011 at 03:45 PM.


  2. #2
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    Default Re: Login website using Java

    Hello cgeier.

    So what happens with the code you have posted? Does it login successfully?
    Please use [highlight=Java] code [/highlight] tags when posting your code.
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