com.google.gwt.http.client

## Interface RequestCallback

-     public interface RequestCallback

  The primary interface a caller must implement to receive a response to a `Request`.

  ### Required Module

  Modules that use this interface should inherit `com.google.gwt.http.HTTP`.

  >     <module>
  >       <!-- other inherited modules, such as com.google.gwt.user.User -->
  >       <inherits name="com.google.gwt.http.HTTP"/>
  >       <!-- additional module settings -->
  >     </module>

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `onError(Request request, java.lang.Throwable exception)` Called when a `Request` does not complete normally.
    `void` | `onResponseReceived(Request request, Response response)` Called when a pending `Request` completes normally.

- - ### Method Detail

    - #### onResponseReceived

          void onResponseReceived(Request request,
                                  Response response)

      Called when a pending `Request` completes normally. Note this method is called even when the status code of the HTTP response is not "OK", 200.
      Parameters:
        `request` - the object that generated this event
        `response` - an instance of the `Response` class

    - #### onError

          void onError(Request request,
                       java.lang.Throwable exception)

      Called when a `Request` does not complete normally. A `RequestTimeoutException` is one example of the type of error that a request may encounter.
      Parameters:
        `request` - the request object which has experienced the error condition, may be null if the request was never generated
        `exception` - the error that was encountered