Spring自定義注釋

Question

我不確定是否有可能輕松做我想做的事情。 我有以下控制器作為休息和websocket控制器：

@RestController
@RequestMapping("rest/user")
@MessageMapping("/user")
public class UserController {

    @Autowired
    private UserRepo userRepo;

    @RequestMapping("/list")
    @MessageMapping("/list")
    @SendTo("/channel/user")
    public apiResImpl list() {      
        Iterable<UserImpl> users = userRepo.findAll();  
        return users != null ? new apiResImpl("success", users) :  new apiResImpl("fail");
    }

 ...

我想在兩個自定義注釋@ApiController和@ApiMapping中包含其中幾個注釋

像這樣的東西：

@ApiController("/user")
public class UserController {

    @Autowired
    private UserRepo userRepo;

     @ApiMapping("/list")
     public apiResImpl list() {     
         Iterable<UserImpl> users = userRepo.findAll(); 
         return users != null ? new apiResImpl("success", users) :  new apiResImpl("fail");
     }

 ...

我遇到的問題是能夠將值傳遞到內部傳遞給spring注釋的自定義注釋中。 這個@interface會是什么樣子？ 任何例子？

謝謝！

Answer 1

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@RequestMapping // meta-annotated RequestMapping 
@MessageMapping // meta-annotated MessageMapping
public @interface ApiController {

     @AliasFor(annotation = RequestMapping.class, attribute = "value") // -> alias for RequestMapping value attribute
     String[] value() default {};

     @AliasFor(annotation = MessageMapping.class, attribute = "value") // -> alias for MessageMapping value attribute
     String[] mvalue() default{};   
}


@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
@Documented
@RequestMapping
@MessageMapping
public @interface ApiMapping {

    @AliasFor(annotation = RequestMapping.class, attribute = "value")
    String[] value() default {};

    @AliasFor(annotation = MessageMapping.class, attribute = "value")
    String[] mvalue() default {};

    @AliasFor(annotation = RequestMapping.class, attribute = "method")
    RequestMethod[] method() default {};
}

參考下面的鏈接，我提出了這個解決方案，使用這種技術，我們可以為元注釋注釋的屬性賦予別名，即（這里是RequestMapping，MessageMapping）。

AliasFor的一個缺點是，它是不可重復的注釋。

http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#_core_container_improvements_2

Answer 2

         @Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
@RestController
@RequestMapping(value="/rest/*")
@MessageMapping
public @interface ApiController {
    String value() default "";

}