AJAX response to a Restful Jersey Resource

[Trilochan Bharadwaj]

Hi,

I have an AJAX client which retrieves a simple string literal (at least tries to) response from a Restful Resource on the server, using a simple Java Client I can see the response OK and do anything with it; But when I use AJAX to retrieve response, the status comes as 0 for XMLHttpRequest Object, despite the fact that readyState value is set to 4. Below is my JS client code:

	// Summary
	// ================================
	// Sends an AJAX request to HCIS Test resource
	hcis.AJAX.send = function(/*final TYPE*/ pType, /*final URL*/ pURL, /*final <?>Function<?>*/ pResponseHandler, /*final String */ pElementId) {
		hcis.LOG.info('sendAndGet');
		// Phase 1 : Intialize XHR.
		hcis.AJAX._xhr = new XMLHttpRequest();
		hcis.LOG.info('readyState : [ ' + hcis.AJAX._xhr.readyState +  ' ] ');
		hcis.LOG.info('status : [ ' + hcis.AJAX._xhr.status +  ' ] ');
		hcis.AJAX._xhr.open(pType,pURL,true);
		hcis.LOG.info('readyState : [ ' + hcis.AJAX._xhr.readyState +  ' ] ');
		hcis.AJAX._xhr.send(null);
		// Phase 2 : hook the response handler with XHR
		hcis.AJAX._xhr.onreadystatechange  = function () {
			hcis.LOG.info('>>> onreadystatechange');
			 if(hcis.AJAX._xhr.readyState == 4 && hcis.AJAX._xhr.status == 200){
				hcis.LOG.info('response : ' + hcis.AJAX._xhr.responseText);
				document.getElementById(pElementId).innerHTML = hcis.AJAX._xhr.responseText;
	 		}
		};
	};

My Restful resource uses Jersey RS implementation, Here's the code for my Resource:

@Path("/HCISRestfulTest")
public final class HCISRestfulTestResource {

	// java docs removed for clarity
	@GET
	@Produces("application/json")
	public final String sayHello() {
		System.out.println(" >>> sayHello( )");
		return "{response : 'OM Namah Shivaya'}";
	}
}

I built a TestNG test case for the same, using simple client code:

       // java docs removed for clarity
       @Test
	public final void testSayHi() {
		final Client client = Client.create();
		final WebResource objWebResource = client.resource("http://localhost:9081/hcis-restful/resources/HCISRestfulTest");
		final ClientResponse response = objWebResource.path("/").type(MediaType.TEXT_PLAIN).get(ClientResponse.class);
		LOG.info("response : { " + response.getStatus() + " }");
	}

^^ The above java code gives response : 200 ... But in case of AJAX client, I get blank response text, When i check status value it is set to '0', but readyState = 4. Please note that I have to use Native AJAX stuff for this, cannot rely on any third party libraries to make AJAX calls (JQuery, Prototype, Dojo et. al.) unfortunately

Any pointers as to where I am doing something wrong?

Trilochan.

Addendum : In case of an AJAX request,

System.out.println(" >>> sayHello( )");

prints on the server, which means the request goes through ... but no response

[Gregg Bolinger]

Wow, that JavaScript code looks scary. Having no clue about what library you are using there, it's going to be difficult to decipher and debug. On a side but related note, your entire JavaScript code could be condensed to the following using JQuery:

$('#' + pElementId).load(pURL);

Isn't that super cool?

[Trilochan Bharadwaj]

Hey Greg,
Thanks for your reply. OK, maybe I over did my log thingie it just helps me debug on firebug better. If you read my entire post though, at the end, I do mention that I can't use, JQuery, Dojo, Prototype, DWR, Moo Tools ... well you get the picture ;)

I understand that there are frameworks that do this kinda thing and condense the code into few lines ...

Trilochan.

Addendum: This is not any third party library, it forms part of an open source framework that I am building and working on, here's the link:
HCIS framework