java 自定义注解的实例详解

@Retention(value=RetentionPolicy.RUNTIME) 
public @interface MyTest { 
 
} 

public class AnnotationDemo1 { 
  @MyTest 
  public void demo1(){ 
    System.out.println("方法1..."); 
  } 
   
  @MyTest 
  public void demo2(){ 
    System.out.println("方法2..."); 
  } 
  @Test 
  public void demo3(){ 
    System.out.println("方法3..."); 
  } 

public class DemoRunner { 
public static void main(String[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, InstantiationException {  
    //获得测试类的class 
    Class clazz=AnnotationDemo1.class; 
    //获得class中的所有的方法 
    Method[] mothods=clazz.getMethods(); 
    //遍历每个方法， 
    for(Method method:mothods){ 
      boolean flag = method.isAnnotationPresent(MyTest.class); 
       System.out.println(flag); 
      if(flag){ 
        // 说明方法上有MyTest注解: 
        method.invoke(clazz.newInstance(), null); 
      } 
    } 
  } 
}