how to enhance method with @RequestMapping annotation declared in interface?

[carrypann]

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  How to enhance method with @RequestMapping annotation declared in it's interface?

Here is the example code

interface RestApi {
    @RequestMapping("/test")
    String test();
}

@RestController
public class RestApiImpl implements RestApi {
    @Override
    public String test() {
        return "test";
    }
}

The problem is that skywalking can not enhance the RestApiImpl.test() method. I guess the reason is skywalking cannot find @RequestMapping annotation in overrided method.

And here is the related source code in sw's spring-plugins:

# RequestMappingMethodInterceptor.java
public class RequestMappingMethodInterceptor extends AbstractMethodInterceptor {
    @Override
    public String getRequestURL(Method method) {
        String requestURL = "";
        RequestMapping methodRequestMapping = method.getAnnotation(RequestMapping.class);
        if (methodRequestMapping.value().length > 0) {
            requestURL = methodRequestMapping.value()[0];
        } else if (methodRequestMapping.path().length > 0) {
            requestURL = methodRequestMapping.path()[0];
        }
        return requestURL;
    }
  // ...

But the method getAnnotation can not get annotation from interface, so how can i solve this problem?

[wu-sheng]

If this is the case, we don't expect you to write in this way. You have to use more reflect API to get that.

[wu-sheng]

This should be not hard, could you try to submit a pull request to fix this?

[liudantop]

I don't think the issue is the reason and test not pass.
found the matcher is the isAnnotatedWith, explain in bytebuddy. the match does not match inherited annotations :
isAnnotatedWith(named("org.springframework.web.bind.annotation.RequestMapping"));

• Matches an {@link AnnotationSource} for declared annotations.
  • This matcher does not match inherited annotations which only exist for classes. Use
  • {@link net.bytebuddy.matcher.ElementMatchers#inheritsAnnotation(net.bytebuddy.matcher.ElementMatcher)}
  • for matching inherited annotations.

[wu-sheng]

This issue is for fixing inheritance annotation meta inform. Yours may be different. You want to instrument the subclass without the annotation.

[liudantop]

case is similar.
If the annotation @RequestMapping("/test") is define interface method. Subclass implement the method， and enhance is inoperative.

thanks

[wu-sheng]

I know it is similar, but at the codes level, it is different. You should be able to provide a pull request to fix this, as you have already been looking at the ByteBuddy APIs. There is only a chance to use suitable API to filter the classes.

[liudantop]

thanks, let me try.