java中实现自定义注解方式

public @interface Info {
    String value() default "tracy";
    boolean isDelete();
}

@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Info {
      String value() default "tracy";
      boolean isDelete();
}

@Data
@Builder
@Define(isDelete = true)
public class People {

    /**
     * 姓名
     */
    private String name;

    /**
     * 年龄
     */
    private int age;

    /**
     * 是否有效
     */
    private boolean isDelete;

}

import java.lang.annotation.*;

@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Define {

    String value() default "tracy";
    boolean isDelete();
}

public static void main(String[] args) {

        try {
            //获取Person的Class对象
            People person = People.builder().build();
            Class clazz = person.getClass();
            //判断person对象上是否有Info注解
            if (clazz.isAnnotationPresent(Define.class)) {
                System.out.println("People类上配置了Define注解！");
                //获取该对象上Info类型的注解
                Define infoAnno = (Define) clazz.getAnnotation(Define.class);
                System.out.println("person.name :" + infoAnno.value() + ",person.isDelete:" + infoAnno.isDelete());
            } else {
                System.out.println("People类上没有配置Define注解！");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

//返回指定的注解
getAnnotation
//判断当前元素是否被指定注解修饰
isAnnotationPresent
//返回所有的注解
getAnnotations