Getting data from a URL.

[Anunay Ashish]

Hi All,
I am developing an applet which I will be embedding in an HTML page. When the HTML page will be launched, it will get a URL and an id. I have to send the id at this URL(representing a Learning Management System). This will cause the information to be sent by the LMS.
I don't know how to ask for information when the information will be sent, how to recieve it at my end.
[ September 27, 2002: Message edited by: Anunay Ashish ]

[Tom Ben]

I am trying to make sure I understand what it is you are asking to better give you an answer. You want to send an id to a url (are you doing it thru a GET type send or a POST type send). Then read thru the response of the url?

[John Smith]

class DatekHttpConnection {
    
    // connection related members
    private final static String logInURL = "https://investment.datek.com/";
    private static URL url;
    private static String formData;
    private static HttpURLConnection connection;
    private static BufferedWriter writer;
    private static BufferedReader reader;
    
    private final String userName;
    private final String password;
    private final String authString;
    private static StringBuffer response;
    private static String serverResponse;
    private static int responseCode;
    private static String responseMessage;
    
    public String getServerResponse() { return serverResponse; }
    
    
    DatekHttpConnection(final String userName, final String password) throws MalformedURLException, IOException {
        
        this.userName = userName;
        this.password = password;
        
        System.setProperty("java.protocol.handler.pkgs", "com.sun.net.ssl.internal.www.protocol");
        Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
        
        // initialize stream handler
        URLStreamHandler handler = new com.sun.net.ssl.internal.www.protocol.https.Handler();
        
        // initialize other member fields
        url = new URL( null, logInURL, handler);
        authString = (new sun.misc.BASE64Encoder()).encode((this.userName + ":" + this.password).getBytes());
        response = new StringBuffer();
            
        // set the security stuff    
        Provider provider = Security.getProvider("SunJSSE");
        if (provider == null) {
            throw new IOException("SunJSSE provider not registered.");
        }
        
    }
    
    
    synchronized void postRequest(String formData) throws IOException {  
        
        // establish the connection (new for every request)
        connection = ( HttpURLConnection ) url.openConnection(); 
        // set the authentication string in the header (username and password, 64-bit encoded)
        connection.setRequestProperty("Authorization", "Basic " + authString);
        // indicate the agent 
        connection.setRequestProperty("User-Agent", "Automated Trading System v2.0");
        
        // set the neccessary properties
        connection.setDoOutput(true);   // allow posting to URL
        connection.setUseCaches(false); // every request is treated as new, no caching
        connection.setAllowUserInteraction(false); // suppress user pop-ups
        
        // no other settings are neccessary. The connection object will set all the rest
        // (content length, request type, etc. automatically)
        // write form data
        if (formData.length() > 0) {
            writer = new BufferedWriter(new OutputStreamWriter(connection.getOutputStream()));
            writer.write(formData, 0, formData.length());
            writer.flush();
            writer.close();
        }
        
        reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        
        // make sure server response is normal
        responseCode = connection.getResponseCode();
        responseMessage = connection.getResponseMessage();
        
        
        response.setLength(0); // clear the buffer where the server response is stored
        String line;
        // read server response                
        while ((line = reader.readLine()) != null)
            response.append(line);
        
        serverResponse = response.toString();
        
        // check the response code
        if (responseCode != HttpURLConnection.HTTP_OK) {
            String msg = "<br><b>Exception message: </b>" + "Couldn't post request." + 
                            "<br><b>Form data: </b>" + formData +
                            "<br><b>Server response code: </b>" + responseCode +
                            "<br><b>Server response message: </b>" + responseMessage +
                            "<br><b>Server response HTML: </b>" + serverResponse;
                            
            msg += "<br><b>Stack trace: </b>"; // Java exception mechanism will append stack trace to this String
            throw new IOException(msg);
        }            
        
        
        // close the response reader and drop the connection
        reader.close();
        connection.disconnect(); 
    }     
}    

Eugene.
[ September 30, 2002: Message edited by: Eugene Kononov ]