post json in android annotations

You can user Retrofit Type-safe REST client for Android and Java.

Use annotations to describe the HTTP request:

• URL parameter replacement and query parameter

support Object

• conversion to request body (e.g., JSON, protocol buffers)
• Multipart request body and file upload

See here a good tutorial Consuming-APIs-with-Retrofit

You can use Gson library for this. Here and here you can find useful tutorials.

Actually i think this is well documented in the AA wiki.

@Rest(rootUrl = "http://company.com/ajax/services", converters = { GsonHttpMessageConverter.class })
public interface MyRestClient {

  @Post("/events")
  void addEvent(Event event);
}

public class Event {
  String description;

  // ...
}

You you can use MappingJacksonHttpMessageConverter instead of GsonHttpMessageConverter if you are using Jackson instead of GSON.

Disclaimer: i am an AndroidAnnotations developer.