java 注解及其反射

自定义注解

package cn.lichaozhang.annotationreflect;

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

@Target({ElementType.TYPE,ElementType.METHOD})
@Retention(value=RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
	public String key() default "LCZ";
	public String value() default "张历超";
}

 应用注解

package cn.lichaozhang.annotationreflect;

public class SimpleBean {

	@MyAnnotation(key="lichaozhang",value="www.iteye.com")
	public String toString(){
		return "Hello Annotation!!!";
	}
}

 

注解解析器

package cn.lichaozhang.annotationreflect;

import java.lang.reflect.Method;

public class MyDefaultAnnotationReflect {
	@SuppressWarnings("unchecked")
	public static void main(String[] args) throws Exception {
		Class clazz = Class.forName("cn.lichaozhang.annotationreflect.SimpleBean");
		Method method = clazz.getDeclaredMethod("toString", null);
		if (method.isAnnotationPresent(MyAnnotation.class)) {
			MyAnnotation myAnnotation = method.getAnnotation(MyAnnotation.class);
			String key = myAnnotation.key();
			String value = myAnnotation.value();
			System.out.println(key + "\t" + value);
		}
	}
}