当使用spring AOP时，判断目标方法上的注解进行相关操作，如缓存，认证权限等

自定义注解

packagecom.agent.annotation;importjava.lang.annotation.ElementType;importjava.lang.annotation.Retention;importjava.lang.annotation.RetentionPolicy;importjava.lang.annotation.Target;importorg.springframework.stereotype.Component;

@Component

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.METHOD)public @interfaceMyAnnotation {public boolean isEnable() default true;

}

Spring AOP的AspectJ

packagecom.agent.aop;importjava.lang.reflect.Method;importorg.aspectj.lang.ProceedingJoinPoint;importorg.aspectj.lang.annotation.Around;importorg.aspectj.lang.annotation.Aspect;importorg.springframework.stereotype.Component;importcom.agent.annotation.MyAnnotation;

@Component

@Aspectpublic classLogUtil {

@Around("@annotation(com.agent.annotation.MyAnnotation)")public Object logWrited(ProceedingJoinPoint point) throwsThrowable {

Object[] args=point.getArgs();

Class>[] argTypes = newClass[point.getArgs().length];for (int i = 0; i < args.length; i++) {

argTypes[i]=args[i].getClass();

}

Method method= null;try{

method=point.getTarget().getClass()

.getMethod(point.getSignature().getName(), argTypes);

}catch(NoSuchMethodException e) {

e.printStackTrace();

}catch(SecurityException e) {

e.printStackTrace();

}

MyAnnotation ma= method.getAnnotation(MyAnnotation.class);

System.out.println(ma.isEnable());returnpoint.proceed();

}

}

Service接口

packagecom.agent.service;public interfaceUserService {voidaddUser(String name, String password);

}

service接口的实现类，被自定义注解所注解

packagecom.agent.service.impl;importorg.springframework.stereotype.Service;importcom.agent.annotation.MyAnnotation;importcom.agent.service.UserService;

@Service(value="userService")public class UserServiceImpl implementsUserService {

@Override

@MyAnnotationpublic voidaddUser(String name, String password) {

System.out.println("UserServiceImpl.addUser()...... name: " + name + "; password: " +password);

}

}

测试类：

packagecom.agent.test;importorg.springframework.context.ApplicationContext;importorg.springframework.context.support.ClassPathXmlApplicationContext;importcom.agent.service.UserService;public classAOPTest {public static voidmain(String[] args) {

ApplicationContext ac= new ClassPathXmlApplicationContext("applicationContext.xml");

UserService us= (UserService)ac.getBean("userService");

us.addUser("张三", "188");

}

}

Spring的配置文件：

http://www.springframework.org/schema/beans/spring-beans.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx.xsd">

测试结果：

如果使用的是接口的模式，而注解在实现类上，则不能使用如下方式获取目标方法的对象，因为该方式获取的是该类的接口或者顶级父类的方法的对象

MethodSignature methodSignature =(MethodSignature)point.getSignature();

Method method= methodSignature.getMethod();