Funny you should ask. We just had to do this:

	public String postDocument(String doc, URL url) {
		HttpURLConnection connection = null;
		BufferedReader r = null;

		try {
		
			// Get the connection 		
			connection = (HttpURLConnection)url.openConnection();
			
                        // Set up the connection parameters.
                        connection.setDoInput(true);
			connection.setDoOutput(true);
			connection.setRequestMethod( "POST" );
			
                        // Get the header properties.
			for(Enumeration e = headers.propertyNames(); e.hasMoreElements() ;) {
				String propName = (String)e.nextElement();
				connection.setRequestProperty( propName, headers.getProperty(propName));
			}
			
			// Get an output stream to send the document
			OutputStream out = connection.getOutputStream();
			Writer wout = new BufferedWriter(new OutputStreamWriter(out));

			// Write the document.
                     	wout.write(doc);
			wout.flush();
			out.close();

                         // Get the response code from the site you are sending to.
			int code = connection.getResponseCode();
                        // Read the response.
			if (code >= HttpURLConnection.HTTP_OK && code < HttpURLConnection.HTTP_MULT_CHOICE) {
				// Read the response
				BufferedReader backin = new BufferedReader(new InputStreamReader(connection.getInputStream()));
				cat.debug("Inspecting the response");
				StringBuffer resp = new StringBuffer();
				while (true) {
				   String line = backin.readLine();
				   if (line == null) break;
				   resp.append(line);
				}
				backin.close();
				cat.debug("Response received: " + resp.toString());
			}
                        // Disconnect the connection
			connection.disconnect();


        } catch (IOException e) {
			failure = connection.getHeaderField(0);
			System.out.println("Unexpected IOExcpetion when trying to POST the data: " + e.getMessage());
			System.out.println("POST Failure: " + failure);
			//e.printStackTrace();
		} finally {
			if (connection != null) connection.disconnect();
		}

		return failure;
	}

You will need a couple of methods to add headers to a Properties Object:

Properties headers = new Properties();

	public void addHeader(String name, String value) {
		headers.setProperty(name, value);
		System.out.println("Setting property " + name + ":" + value);
	}

You would set up the HTTP headers you need by calling the above method. Then, pass
the document and the URL you want to send it to to the postDocument() method.

Hope this helps

Stephen McConnell