Spring中AOP的实现方式

Spring中AOP的实现方式

service层的接口和实现类

package com.harris.service;

public interface UserService {
    void add();
    void delete();
    void update();
    void select();
}

package com.harris.service;

public class UserServiceImpl implements UserService{
    @Override
    public void add() {
        System.out.println("增加一个用户");
    }

    @Override
    public void delete() {
        System.out.println("删除一个用户");
    }

    @Override
    public void update() {
        System.out.println("修改一个用户");
    }

    @Override
    public void select() {
        System.out.println("查询一个用户");
    }
}

Log 层

Log

通过继承MethodService 和配置文件实现AOP 切入

package com.harris.Log;

import org.springframework.aop.MethodBeforeAdvice;

import java.lang.reflect.Method;

public class Log implements MethodBeforeAdvice {
    @Override
    public void before(Method method, Object[] objects, Object o) throws Throwable {
        System.out.println(o.getClass().getName()+"的方法"+method.getName()+"被执行了");
    }
}

AfterLog

package com.harris.Log;

import org.springframework.aop.AfterReturningAdvice;

import java.lang.reflect.Method;

public class AfterLog implements AfterReturningAdvice {
    @Override
    public void afterReturning(Object o, Method method, Object[] objects, Object o1) throws Throwable {
        System.out.println("执行了"+method.getName()+"返回结果为: "+o);
    }
}

xml配置文件

<?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: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/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">

    <bean id="userservice" class="com.harris.service.UserServiceImpl"/>
    <bean id="log" class="com.harris.Log.Log"/>
    <bean id="afterlog" class="com.harris.Log.AfterLog"/>
    <!-- 方式一: 使用原生的Spring API 接口
       需要导入AOP约束
    -->
    <aop:config>
        <!--切入点 表达式: execution("位置") -->
        <aop:pointcut id="pointcut" expression="execution(* com.harris.service.UserServiceImpl.*(..))"/>
        <!--增强环绕 -->
        <aop:advisor advice-ref="log" pointcut-ref="pointcut"/>
        <aop:advisor advice-ref="afterlog" pointcut-ref="pointcut"/>
    </aop:config>
</beans>

测试类

import com.harris.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService userservice = (UserService) context.getBean("userservice");
        userservice.add();
    }
}

运行结果

---

遇到的一个小问题：
BeanFactory not initialized or already closed - call 'refresh' before accessing beans via the ApplicationContext

这是说明测试类的CPX的xml文件路径没有写对。

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