java8新特性 -------------重复注解与类型注解

import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.LOCAL_VARIABLE;

/**
 * create gl
 **/
@Repeatable(MyAnnotations.class)  // 定义重复注解，指定容器类
@Target({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, LOCAL_VARIABLE,TYPE_PARAMETER})
@Retention(RetentionPolicy.RUNTIME)   // 生命周期
public @interface MyAnnotation {
    String value() default "666";
}

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.LOCAL_VARIABLE;

/**
 * create gl
 **/
@Target({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, LOCAL_VARIABLE})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotations {
    MyAnnotation[] value();
}

mport java.lang.reflect.Method;

/**
 * create gl 
 *   重复注解  与 类型注解
 **/
public class TestAnno {

    private @NotNull User user;

    @MyAnnotation("hello")
    @MyAnnotation("world")
    public void show(@MyAnnotation("123") String str){

    }

    public static void main(String[] args) throws NoSuchMethodException {
        Class annoClass = TestAnno.class;
        Method show = annoClass.getMethod("show");
        MyAnnotation[] annotationsByType = show.getAnnotationsByType(MyAnnotation.class);
        for (MyAnnotation mat:annotationsByType) {
            System.out.println(mat.value());
        }
    }


}