Question

I would like to know more about using Ajax with DWR and Jquery Ajax in Java. Is there any advantage over the other?

Answer 1

In the simplest terms, DWR is an engine that exposes methods of server-side Java objects to JavaScript code. Effectively, with DWR, you can eliminate all of the machinery of the Ajax request-response cycle from your application code. This means your client-side code never has to deal with an XMLHttpRequest object directly, or with the server’s response. You don’t need to write object serialization code or use third-party tools to turn your objects into XML. You don’t even need to write servlet code to mediate Ajax requests into calls on your Java domain objects.

DWR is deployed as a servlet within your Web application. Viewed as a black box, this servlet performs two major roles: First, for each exposed class, DWR dynamically generates JavaScript to include in your Web page. The generated JavaScript contains stub functions that represent the corresponding methods on the Java class and also performs XMLHttpRequests behind the scenes. These requests are sent to the DWR servlet, which, in its second role, translates the request into a method call on a server-side Java object and sends the method’s return value back to the client side in its servlet response, encoded into JavaScript. DWR also provides JavaScript utility functions that help perform common UI tasks.