Java8新特性之重复注解与类型注解

重复注解

@Repeatable

@Repeatable(MyAnnotations.class)
@Target({ElementType.TYPE,ElementType.FIELD,ElementType.METHOD,ElementType.LOCAL_VARIABLE,ElementType.CONSTRUCTOR})
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value() default "fjh";
}

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

@Test
public void test1() throws Exception {
    Class<TestAnnotation> clazz = TestAnnotation.class;
    Method method = clazz.getMethod("show");
    MyAnnotation[] ma = method.getAnnotationsByType(MyAnnotation.class);
    for (MyAnnotation myAnnotation : ma) {
        System.out.println(myAnnotation.value());
    }
}

@MyAnnotation("1")
@MyAnnotation("2")
public void show(){

}

类型注解

@Target({ElementType.TYPE_PARAMETER})