In many cases a resource class can return a standard Java type, a JAXB object, or any object for which the application has an entity provider. In these cases the runtime determines the MIME type information using the Java class of the object being returned. The runtime also determines the appropriate HTTP return code to send to the consumer.
Resource methods can return
void or any Java type for which an entity writer is provided. By default, the runtime has providers for the following:
The runtime determines the MIME type of the returned entity by first checking the resource method and resource class for a
@Produces annotation. If it finds one, it uses the MIME type specified in the annotation. If it does not find one specified by the resource implementation, it relies on the entity providers to determine the proper MIME type.
By default the runtime assign MIME types as follows:
When resource methods return plain Java constructs, the runtime automatically sets the response's status code if the resource method completes without throwing an exception. The status code is set as follows:
204(No Content)—the resource method's return type is
204(No Content)—the value of the returned entity is
200(OK)—the value of the returned entity is not