在Java中提供RESTful JSON API

Question

What is the idiomatic way of providing RESTful JSON API in Java? Do you use JAX-WS and XML annotations (@XmlElement etc.)? How do you serialize annotated objects to JSON (using Jackson or similar library)? How do you separate domain objects from objects sent out to API?

I know Java, I would like you to point me out to good resources and best practices about these topics.

Thank you!

Answer 1

I have used happily Jersey/JAX-RS but I would suggest you Spring MVC 3 , not only for the rest api support but also for other interesting stuff as IoC or beans that could turn out to be useful.

Here a link where to refer: http://blog.springsource.org/2009/03/08/rest-in-spring-3-mvc/

Btw, I've used Jackson with Spring as parser. :)

---

A bit of code (basically mark your bean, as you said, with @XmlRootElement and use @Path to mark the API)

JAX-RS

bean:

@XmlRootElement
public class Response {

  private String result;
  private String message;

  //getter and setter
}

api:

@Path("rest/user")
@Produces(MediaType.APPLICATION_JSON)
public class UserService {

  @POST
  @Path("/login")
  public Response login(
        @FormParam("username") String username,
        @FormParam("password") String password
  ) {
      // Your logic here
  }
}

Spring

api:

@Controller
@RequestMapping("/user")
public class UserService {

  @RequestMapping(method = RequestMethod.POST, value="/login", headers="Accept=application/json")
  public @ResponseBody Response login(
        @RequestParam(value = "user", defaultValue = "") String email,
        @RequestParam(value = "password", defaultValue = "") String password,
        HttpServletRequest request
        ) {
    // Your logic here
  }
}

Answer 2

I would simply use Play to save me a lot of work that has already been done. The link is for Play 1.2 and while the current version is 2.1, it should be fit for that as well.

Answer 3

I have good experience with Jersey and Jackson, even with Android, JBoss or Tomcat. See:

http://www.mkyong.com/webservices/jax-rs/restful-java-client-with-jersey-client/ and http://www.mkyong.com/webservices/jax-rs/json-example-with-jersey-jackson/

or

An Android REST Client and Tomcat REST Webservice