HTTP POST within an application

Question

hi, i am very new to java and just reached my next problem ;)
what i want to do is post some data to a webserver from within my application and get the answer of the server back to a string (or something like that).
what do i have to do for this?

Answer 1

Hey there-
You need to use the HttpURLConnection class to get connected to your web server. To get this you create a new URL object pointing to the web server, then cast the object returned from your URL's openConnection() method to be an HttpURLConnection - something like:
URL myURL = new URL("http://something.com");
HttpURLConnection httpURLCon = (HttpURLConnection)myURL.openConnection();Then you need to make your post. Do this by adding your data elements to the HttpURLConnection's request properties via the setRequestProperty method, like:
httpURLCon.setRequestProperty("Name", name);Then you set up the connection for a post by setting its request method to "POST" (use the setRequestMethod method) and call setDoOutput(true) and setDoInput(true). This says you are doing a POST, and you want to both write the data out, and read what comes back.
Finally you want to make the post and read the result from the server. You do this by writing your data to the output stream of your HttpURLConnection object and then reading data from its input stream, doing something like:
// Send the data
DataOutputStream dos = new DataOutputStream( httpURLCon.getOutputStream() );
dos.writeBytes( data );
dos.close();
// Read the results
DataInputStream dis = new DataInputStream(httpURLCon.getInputStream() );
String nextLine = null;
StringBuffer results = new StringBuffer();
while((nextLine = dis.readLine()) != null) {
    results.append(nextLine + "\n");
dis.close();That should do it.
Good luck to ya
Lee