Java AccessibleObject isAnnotationPresent()方法

java.lang.reflect.AccessibleObject.isAnnotationPresent(Class<? extends Annotation> annotationClass)方法返回true，否则返回true。

1 语法

public boolean isAnnotationPresent(Class<? extends Annotation>  annotationClass)

2 参数

annotationClass ：与注解类型对应的Class对象。

3 返回值

如果此元素上存在指定注解类型的注解则为true，否则为false。

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * Java AccessibleObject isAnnotationPresent()方法
 */
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;

public class AccessibleObjectDemo {
   public static void main(String[] args) throws NoSuchMethodException, 
      SecurityException, NoSuchFieldException {
      AccessibleObject sampleMethod = SampleClass.class.getMethod("sampleMethod");
      System.out.println("sampleMethod.isAnnotationPresent: " 
         + sampleMethod.isAnnotationPresent(CustomAnnotation.class));
   }
}

@CustomAnnotation(name="SampleClass",  value = "Sample Class Annotation")
class SampleClass {
   private String sampleField;

   @CustomAnnotation(name="sampleMethod",  value = "Sample Method Annotation")
   public String sampleMethod(){
      return "sample";
   }

   public String getSampleField() {
      return sampleField;
   }

   public void setSampleField(String sampleField) {
      this.sampleField = sampleField;
   } 
}

@Retention(RetentionPolicy.RUNTIME)
@interface CustomAnnotation {
   public String name();
   public String value();
}

输出结果为：

sampleMethod.isAnnotationPresent: true