Difference between JAX-RS and Spring Rest

Question

I confused with the difference between JAX-RS (well, maybe should use Jersey to do comparison since JAX-RS is just spec) and Spring for Restful serv

Answer 1

JAX-RS

JAX-RS is a specification for implementing REST web services in Java, currently defined by the JSR-370. It is part of the Java EE technologies, currently defined by the JSR 366.

Jersey (shipped with GlassFish and Payara) is the JAX-RS reference implementation, however there are other implementations such as RESTEasy (shipped with JBoss EAP and WildFly) and Apache CXF (shipped with TomEE and WebSphere).

Spring Framework

The Spring Framework is a full framework that allows you to create Java enterprise applications. The REST capabilities are provided by the Spring MVC module (same module that provides model-view-controller capabilities). It is not a JAX-RS implementation and can be seen as a Spring alternative to the JAX-RS standard.

The Spring ecosystem also provides a wide range of projects for creating enterprise applications, covering persistence, security, integration with social networks, batch processing, etc.

Examples

Consider the following resource controller using the JAX-RS API:

@Path("/greetings")
public class JaxRsController {

    @GET
    @Path("/{name}")
    @Produces(MediaType.TEXT_PLAIN)
    public Response greeting(@PathParam("name") String name) {

        String greeting = "Hello " + name;
        return Response.ok(greeting).build();
    }
}

The equivalent implementation using the Spring MVC API would be:

@RestController
@RequestMapping("/greetings")
public class SpringRestController {

    @RequestMapping(method = RequestMethod.GET,
                    value = "/{name}", 
                    produces = MediaType.TEXT_PLAIN_VALUE)
    public ResponseEntity greeting(@PathVariable String name) {

        String greeting = "Hello " + name;
        return new ResponseEntity<>(greeting, HttpStatus.OK);
    }
}

Using Spring Boot and Jersey

Spring Boot provides the spring-boot-starter-jersey module that allows you to use the JAX-RS programming model for the REST endpoints instead of Spring MVC. It works quite well with Jersey 2.x.

For a complete example of creating a web application with Jersey 2.x and Spring Boot 1.4.x, refer to this answer.