How can we retrieve annotations on attributes in Java?

In Java, annotations on attributes can be obtained through reflection. The following are the steps for obtaining annotations on attributes.

1. Get the Class object of the attribute.
2. retrieve the declared field
3. retrieve the annotation

Here is an example code:

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@interface MyAnnotation {
    String value();
}

class MyClass {
    @MyAnnotation("示例注解")
    private String myField;

    public String getMyField() {
        return myField;
    }
}

public class Main {
    public static void main(String[] args) throws NoSuchFieldException {
        MyClass obj = new MyClass();

        // 获取属性对象
        Class<?> cls = obj.getClass();
        Field field = cls.getDeclaredField("myField");

        // 获取属性上的注解对象
        MyAnnotation annotation = field.getAnnotation(MyAnnotation.class);
        System.out.println(annotation.value());
    }
}

The output shows “Example annotation,” indicating that the annotation on the property has been successfully retrieved.