如何从ProceedingJoinPoint获取方法的注释值？ [英] How to get a method's annotation value from a ProceedingJoinPoint?

问题描述

我有以下注释。

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {

}

SomeAspect.java

SomeAspect.java

public class SomeAspect{

 @Around("execution(public * *(..)) && @annotation(com.mycompany.MyAnnotation)")
    public Object procede(ProceedingJoinPoint call) throws Throwable {

  //Some logic

}

}

SomeOther.java

SomeOther.java

public class SomeOther{

@MyAnnotation("ABC") 
public String someMethod(String name){


}


}

在上面的课程中，我在 @MyAnnotation 中传递 ABC 。
现在我如何在 SomeAspect.java 类的 procede 方法中访问 ABC 值？

In above class am passing "ABC" with in @MyAnnotation. Now how can i access "ABC" value in procede method of SomeAspect.java class?

谢谢！

推荐答案

你可以得到签名。 org / aspectj / doc / released / runtime-api / org / aspectj / lang / ProceedingJoinPoint.htmlrel =noreferrer> ProceedingJoinPoint ，如果是方法调用，只需将其转换为 MethodSignature 。

You can get the Signature from a ProceedingJoinPoint and in case of a method invocation just cast it to a MethodSignature.

@Around("execution(public * *(..)) && @annotation(com.mycompany.MyAnnotation)")
public Object procede(ProceedingJoinPoint call) throws Throwable {
    MethodSignature signature = (MethodSignature) call.getSignature();
    Method method = signature.getMethod();

    MyAnnotation myAnnotation = method.getAnnotation(MyAnnotation.class);
}

但您应首先添加注释属性。您的示例代码没有，例如<​​/ p>

But you should first add an annotation attribute. Your example code doesn't have one, e.g.

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {

    String value();
}

然后你可以访问它

MyAnnotation myAnnotation = method.getAnnotation(MyAnnotation.class);
String value = myAnnotation.value();

编辑

如果我在课程级别拥有@MyAnnotation（ABC），如何获得价值？

How to get value if I have @MyAnnotation("ABC") at class level ?

Class 也是 AnnotatedElement ，因此您可以使用与方法。例如。可以使用

A Class is also an AnnotatedElement, so you can get it the same way as from a Method. E.g. An annotation of the method's declaring class can be obtained using

 Method method = ...;
 Class<?> declaringClass = method.getDeclaringClass();
 MyAnnotation myAnnotation = declaringClass.getAnnotation(MyAnnotation.class)

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