Spring tool class--Usage of AnnotatedElementUtils

Original URL: Spring Tool Class--Usage of AnnotatedElementUtils_IT Knives Out Blog-CSDN Blog

Introduction

This article introduces the use of Spring's AnnotatedElementUtils tool class.

The difference between AnnotatedElementUtils and AnnotationUtils: (AnnotatedElementUtils is more powerful)

characteristic	AnnotatedElementUtils	AnnotationUtils
Function	Handle multiple annotations on elements such as classes, methods, fields, etc.	Process individual annotations.
scope	Can handle multiple annotations, and can handle the situation where multiple annotations are related to each other.	Only specified annotations can be processed, and relationships between multiple annotations cannot be processed.
Annotation inheritance relationship	Can identify the inheritance relationship of annotations. for example: 1. Child annotations are used, but they can be judged by the parent annotation class. 2. Obtain the value of the child annotation through the parent annotation	Unable to recognize inheritance relationship of annotations
Annotation search scope	Searching for annotations will recursively look for annotations on the element's parent class and interface.	Only searches for annotations on the passed in element itself.

usage

annotation

package com.example.annotation;

import org.springframework.core.annotation.AliasFor;

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
@Documented
@Inherited
public @interface MyAnnotation {
    @AliasFor(attribute = "location")
    String value() default "";
    
    @AliasFor(attribute = "value")
    String location() default "";
}

package com.example.annotation;

import org.springframework.core.annotation.AliasFor;
 
import java.lang.annotation.*;
 
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
@Documented
@Inherited
@MyAnnotation
public @interface SubMyAnnotation {
    @AliasFor(annotation = MyAnnotation.class)
    String location() default "";

//    这个不能写，只能有一个与父属性名同名的属性，否则报错
//    @AliasFor(annotation = MyAnnotation.class)
//    String value() default "";
}

controller

The above is part of the article. For the convenience of maintenance, the full text has been transferred to this URL: Spring Tool Class-Usage of AnnotatedElementUtils-Self-Study Elf