GET Request with Content-Type and Accept header with JAX-RS Jersey 2.2

Question

I try to access an open data web service which gives me traffic infos. Documentation says that requests have to be GET and need to contain Accept: applica

Answer 1

Isn't accept(MediaType.APPLICATION_JSON) and header("Content-type","application/json") the same?

No, they are different.
This is how they are related:

Client                     Server
(header)                   (class/method annotation)
====================================================
Accept          <--->      @Produces
Content-Type    <--->      @Consumes

The server consumes what it receives from the client in body (its format is specified in Content-Type) and it produces what the client accepts (its format is specified in Accept).

Example:

• client sends the following headers:
  • Content-Type = text/xml (it sends an XML in body)
  • Accept = application/json (it expects to get a JSON as a response)
• server needs to have at least the following annotations for the corresponding method (the annotations are taken from the class level, if they are not explicitly mentioned for that method):
  • @Consumes(MediaType.TEXT_XML) (it gets an XML from the client)
  • @Produces(MediaType.APPLICATION_JSON) (it sends a JSON to the client)

Obs:

1. The server can be more flexible, being configured to get/produce multiple possible formats.

   E.g.: a client can send an XML while another client can send a JSON to the same method if it has the following annotation: @Consumes({ MediaType.APPLICATION_JSON, MediaType.TEXT_XML }).

2. The MediaType values are just String constants:

   public final static String APPLICATION_JSON = "application/json";
   public final static String TEXT_XML = "text/xml";