Spring AOP 的实现

软件152 余建强

1 使用 API 实现 AOP

新建一个用户接口：UserService

 package com.cqvie.aop.api;

 public interface UserService {

     public void add(String name);
     public void update(String name);
     public void delete(String name);
     public void select(String name);
 }

实现接口类：UserServiceImpl

 package com.cqvie.aop.api;

 public class UserServiceImpl implements UserService {

     @Override
     public void add(String name) {
         System.out.println("Add User " + name + " SUCCESS!");
     }

     @Override
     public void update(String name) {
         System.out.println("Update User " + name + " SUCCESS!");
     }

     @Override
     public void delete(String name) {
         System.out.println("Delete User " + name + " SUCCESS!");
     }

     @Override
     public void select(String name) {
         System.out.println("Select User " + name + " SUCCESS!");
     }

 }

写一个日志类，包括前置通知和后置通知：Log

 package com.cqvie.aop.api;

 import java.lang.reflect.Method;

 import org.springframework.aop.AfterReturningAdvice;
 import org.springframework.aop.MethodBeforeAdvice;

 public class Log implements MethodBeforeAdvice, AfterReturningAdvice {

     /**
      * 前置通知
      * @param method 被调用方法对象
      * @param args 被调用的方法参数
      * @param target 被调用的方法的目标对象
      */
     @Override
     public void before(Method method, Object[] args, Object target) throws Throwable {
         System.out.println(target.getClass().getName() + " 的 " +
                 method.getName() + "方法被执行···");
     }

     /**
      * 后置通知
      * @param returnValue 返回值
      * @param method 被调用的方法对象
      * @param args 被调用的方法对象的参数
      * @param target 被调用的方法对象的目标对象
      */
     @Override
     public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
         System.out.println(target.getClass().getName() + " 的 " +
                 method.getName() + "方法已成功执行！返回值为：" + returnValue);
         System.out.println();
     }
 }

配置 Spring 的配置文件：applicationContext01.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          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">

     <bean id="userService" class="com.cqvie.aop.api.UserServiceImpl"></bean>
     <bean id="log" class="com.cqvie.aop.api.Log"></bean>
     <aop:config>
         <aop:pointcut expression="execution(* com.cqvie.aop.api.UserServiceImpl.*(..))" id="pointcut"/>
         <aop:advisor advice-ref="log" pointcut-ref="pointcut"/>
     </aop:config>

 </beans>

添加一个测试类：Test

 package com.cqvie.aop.api;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 public class Test {

     public static void main(String[] args) {

         @SuppressWarnings("resource")
         ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext01.xml");
         UserService userService = (UserService) ac.getBean("userService");
         userService.update("AngeYu");
         userService.delete("AngeYu");

     }

 }

运行结果：

2 自定义类实现 AOP

接口和接口的实现类不变，依旧是上面所提到的 UserService 和 UserServiceIpml

自己写一个日志类 Log，包含前置通知和后置通知

 package com.cqvie.aop.custom;

 public class Log {

     public void before() {
         System.out.println("----- method start -----");
     }

     public void after() {
         System.out.println("----- method end -----");
     }

 }

配置 Spring 的配置文件：applicationContext02.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          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">

     <bean id="userService" class="com.cqvie.aop.custom.UserServiceImpl"></bean>
     <bean id="log" class="com.cqvie.aop.custom.Log"></bean>
     <aop:config>
         <aop:aspect ref="log">
             <aop:pointcut expression="execution(* com.cqvie.aop.custom.UserServiceImpl.*(..))" id="pointcut"/>
             <aop:before method="before" pointcut-ref="pointcut"/>
             <aop:after method="after" pointcut-ref="pointcut"/>
         </aop:aspect>
     </aop:config>

 </beans>

添加一个测试类：Test

 package com.cqvie.aop.custom;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 public class Test {

     public static void main(String[] args) {

         @SuppressWarnings("resource")
         ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext02.xml");
         UserService userService = (UserService) ac.getBean("userService");
         userService.update("AngeYu");

     }

 }

运行结果：

3 使用注解实现 AOP

接口和接口的实现类不变，依旧是上面所提到的 UserService 和 UserServiceIpml

自己写一个日志类 Log，包含前置通知、后置通知、环绕通知

 package com.cqvie.aop.annotation;

 import org.aspectj.lang.ProceedingJoinPoint;
 import org.aspectj.lang.annotation.After;
 import org.aspectj.lang.annotation.Around;
 import org.aspectj.lang.annotation.Aspect;
 import org.aspectj.lang.annotation.Before;

 @Aspect
 public class Log {

     @Before("execution(* com.cqvie.aop.annotation.UserServiceImpl.*(..))")
     public void before() {
         System.out.println("----- method start -----");
     }

     @After("execution(* com.cqvie.aop.annotation.UserServiceImpl.*(..))")
     public void after() {
         System.out.println("----- method end -----");
     }

     @Around("execution(* com.cqvie.aop.annotation.UserServiceImpl.*(..))")
     public Object around(ProceedingJoinPoint pj) throws Throwable {
         System.out.println("--- around start ---");
         System.out.println("方法签名：" + pj.getSignature());
         Object result = pj.proceed();
         System.out.println("--- around end ---");
         return result;
     }

 }

配置 Spring 的配置文件：applicationContext03.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          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">

     <bean id="userService" class="com.cqvie.aop.annotation.UserServiceImpl"></bean>
     <bean id="log" class="com.cqvie.aop.annotation.Log"></bean>
     <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

 </beans>

添加一个测试类：Test

 package com.cqvie.aop.annotation;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 public class Test {

     public static void main(String[] args) {

         @SuppressWarnings("resource")
         ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext03.xml");
         UserService userService = (UserService) ac.getBean("userService");
         userService.update("AngeYu");

     }

 }

运行结果：