Layar Unable to reach POI provider

I've a service located at http://XXXX:8080/LayarServer/getPOIs/

When I try to load the data in layar I got the error message

POI fwd url = http://XXXX:8080/LayarServer/getPOIs/?lang=en&a开发者_StackOverflow中文版mp;countryCode=AF&lon=4.887339&userId=6f85d06929d160a7c8a3cc1ab4b54b87db99f74b&developerId=0&developerHash=656ed5f931eb524afba243f10a8b57f6e25c8c94&version=4.0&radius=1500&timestamp=1309289916569&lat=52.377544&layerName=testacquisition&accuracy=100 Unable to reach POI provider. Error: No content available

But when I take the data from the server and place it onto a google apps engine as .js file and set the endpoint to this file, it works great.

I don't know what might be the problem. I believe it is not a problem of the returned data.

Now, I know the problem is the server returns an HTTP error code 500, although it doesn't throw any exception can anyone help me figure this out?

I'm very glad I could find the answer after struggling a lot :)

It's all about adding @ResponseBody.