使用服务器端Ruby REST API的Java Ajax Client应用程序中的错误

Question

I have a client side application in java (JSP + AJAX + JQUERY) and a server side application in ruby that exposes a REST API. i am trying to have the client application consume this ruby based REST API using the following code:

$.ajax({
    type: 'GET',
    url: 'http://localhost:4567/apps',
    success : function(data){
        alert ('success'); 
    },
    error : function(jqXHR, textStatus, errorThrown){
        alert(jqXHR.status);
        alert(textStatus);
        alert(errorThrown);
    }
}); 

However, the error component is invoked each time I try. The server side code is as follows:

get "/apps" do
 apps = get_apps
 apps.map { |a| a.name }.to_json
end

When I make a call to the above REST API using browser

(http://localhost:4567/apps) 

I get the expected response which is a string of app names in json format.

Also, I checked the ruby console, for calls from browser I have the following response:

Computer Name - - [15/Apr/2014:12:29:19 India Standard Time] "GET /apps HTTP/1.1" 200 186

and for calls from the java application all I have on the console is:

http://localhost:8080/MyApp/pages/index.jsp -> /apps

I wonder what is wrong here. Would be great if some one could help out please.

Answer 1

Found the answer to my own question.

Same-origin policy restricts pages running scripting to access DOM on different sites. Since this policy applies to XMLHttpRequest, I was not able to get through.

Please see http://en.wikipedia.org/wiki/Same-origin_policy for further details.