Sub-Resources in spring REST

Question

I'm trying to build messanger app.

I've to call CommentResource from MessageResource.

I want separate MessageResources and CommentResources.

I'm doing something like this :

MessageResource.java

@RestController
@RequestMapping("/messages")
public class MessageResource {

    MessageService messageService = new MessageService();

    @RequestMapping(value = "/{messageId}/comments")
    public CommentResource getCommentResource() {
        return new CommentResource();
    }
}

CommentResource.java

@RestController
@RequestMapping("/")
public class CommentResource {

    private CommentService commentService = new CommentService();

    @RequestMapping(method = RequestMethod.GET, value="/abc")
    public String test2() {
        return "this is test comment";
    }
}

I want

http://localhost:8080/messages/1/comments/abc

to return "this is test comment".

Any Idea??

PS: In a simple word, I want to know JAX-RS sub-resource equivalent implementation in spring-rest

Answer 1

In Spring boot, we can implement JAX-RS subresource concept using @Autowired Spring Concept. Create an object of your child resource class and Spring will initialize at runtime and return that object. Don't create an Object manually. like: Above mention scenario

 - MessageResource.java

@RestController
@RequestMapping("/messages")
public class MessageResource {

    MessageService messageService = new MessageService();
    @Autowired
    @Qualifier("comment")
    CommentResource comment;

    @RequestMapping(value = "/{messageId}/comments")
    public CommentResource getCommentResource() {
        return comment;
    }
}    

 - CommentResource.java

@RestController("comment")
@RequestMapping("/")
public class CommentResource {

    private CommentService commentService = new CommentService();

    @RequestMapping(method = RequestMethod.GET, value="/abc")
    public String test2() {
        return "this is test comment";
    }
}



Now it will work like sub-resource
http://localhost:8080/messages/1/comments/abc

You can send any type of request.