Jquery .post que faz o mesmo que o método HttpClient client.executeMethod(post)

private static String getTicketGrantingTicket(final String server,
			final String username, final String password) {
		final HttpClient client = new HttpClient();

		final PostMethod post = new PostMethod(server);

		post.setRequestBody(new NameValuePair[] {
				new NameValuePair("username", username),
				new NameValuePair("password", password) });

		try {
			client.executeMethod(post);

			final String response = post.getResponseBodyAsString();

			// System.out.println(post.getResponseHeader("location"));

			switch (post.getStatusCode()) {
			case 201: {
				final Matcher matcher = Pattern.compile(
						".*action=\".*/(.*?)\".*").matcher(response);

				if (matcher.matches())
					return matcher.group(1);

				LOG.warning("Successful ticket granting request, but no ticket found!");
				LOG.info("Response (1k): "
						+ response.substring(0,
								Math.min(1024, response.length())));
				break;
			}

			default:
				LOG.warning("Invalid response code (" + post.getStatusCode()
						+ ") from CAS server!");
				LOG.info("Response (1k): "
						+ response.substring(0,
								Math.min(1024, response.length())));
				break;
			}
		}

		catch (final IOException e) {
			LOG.warning(e.getMessage());
		}

		finally {
			post.releaseConnection();
		}

		return null;
	}

$(document).ready(function($) {
   
	$("#btn_login").click( logarUsuario );
	
});

function logarAluno() {
	
	var username = $("#username").val();
	var password = $("#password").val();
	
	$.post('url do servidor cas', {username: username, password: password}, function(data) {
		
		alert("oi");

	});
}