Difference between spring @Controller and @RestCon

Question

Difference between spring @Controller and @RestController annotation.

Can @Controller annotation be used for both Web MVC and REST applications?
If yes, how can we differentiate if it is Web MVC or REST application.

Answer 1

In the code below I'll show you the difference between @controller

@Controller
public class restClassName{

  @RequestMapping(value={"/uri"})
  @ResponseBody
  public ObjectResponse functionRestName(){
      //...
      return instance
   }
}

and @RestController

@RestController
public class restClassName{

  @RequestMapping(value={"/uri"})
  public ObjectResponse functionRestName(){
      //...
      return instance
   }
}

the @ResponseBody is activated by default. You don't need to add it above the function signature.

Answer 2

@RestController annotated classes are the same as @Controller but the @ResponseBody on the handler methods are implied.

Answer 3

@RestController was provided since Spring 4.0.1. These controllers indicate that here @RequestMapping methods assume @ResponseBody semantics by default.

In earlier versions the similar functionality could be achieved by using below:

1. @RequestMapping coupled with @ResponseBody like @RequestMapping(value = "/abc", method = RequestMethod.GET, produces ="application/xml") public @ResponseBody MyBean fetch(){ return new MyBean("hi") }

2. <mvc:annotation-driven/> may be used as one of the ways for using JSON with Jackson or xml.

3. MyBean can be defined like

@XmlRootElement(name = "MyBean") @XmlType(propOrder = {"field2", "field1"}) public class MyBean{ field1 field2 .. //getter, setter }

4. @ResponseBody is treated as the view here among MVC and it is dispatched directly instead being dispatched from Dispatcher Servlet and the respective converters convert the response in the related format like text/html, application/xml, application/json .

However, the Restcontroller is already coupled with ResponseBody and the respective converters. Secondly, here, since instead of converting the responsebody, it is automatically converted to http response.

Answer 4

• @Controller is used to mark classes as Spring MVC Controller.
• @RestController is a convenience annotation that does nothing more than adding the @Controller and @ResponseBody annotations (see: Javadoc)

So the following two controller definitions should do the same

@Controller
@ResponseBody
public class MyController { }

@RestController
public class MyRestController { }

Answer 5

If you use @RestController you cannot return a view (By using Viewresolver in Spring/springboot) and yes @ResponseBody is not needed in this case.

If you use @controller you can return a view in Spring webMVC.

Answer 6

As you can see in Spring documentation (Spring RestController Documentation) Rest Controller annotation is the same as Controller annotation, but assuming that @ResponseBody is active by default, so all the json are parsed to java objects.