Spring RESTful Web服务和bean的“请求”和“会话”范围

Question

I am using the pure example code of simple REST service from the spring guide as a base: http://spring.io/guides/gs/rest-service/

I have added single Bean configuration:

@Configuration
public class Config {

    @Bean
    @Scope(value = WebApplicationContext.SCOPE_REQUEST)

    public RequestData requestHelper() {
        return new RequestData();
    }     

}

Then my modified controller looks as follows:

@RestController
public class GreetingController {

    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong();

    AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(Config.class);

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value="name", defaultValue="World") String name) {
        System.out.println(applicationContext.getBean(RequestData.class));

        return new Greeting(counter.incrementAndGet(),
                            String.format(template, name));
    }
}

and I am getting

java.lang.IllegalStateException: No Scope registered for scope 'session']

as the result of calling "/greeting"

I have read some description here: http://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html however I am still confused.

they write: "The request, session, and global session scopes are only available if you use a web-aware Spring ApplicationContext implementation".

Does it mean that "AnnotationConfigApplicationContext" which I am using is not allowed in such case? Am I forced to use some xml configuration instead?

Answer 1

The quote

web-aware Spring ApplicationContext implementation

refers to an appropriate subclass of WebApplicationContext . You're instantiating a AnnotationConfigApplicationContext which is not a subtype of WebApplicationContext and which does not register the SESSION and REQUEST scopes.

It also makes very little sense to create a brand new ApplicationContext in your @RestController . The @RestController object is already a bean within a Spring WebApplicationContext . Just add your new request scoped @Bean to that context and autowire into your controller.