2. AOP配置文件方式的入门

创建maven项目，坐标依赖

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.2.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.2</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.0.2.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.12</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
    <!--AOP联盟-->
    <dependency>
        <groupId>aopalliance</groupId>
        <artifactId>aopalliance</artifactId>
        <version>1.0</version>
    </dependency>
    <!--Spring Aspects-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.0.2.RELEASE</version>
    </dependency>
    <!--aspectj-->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.3</version>
    </dependency>
</dependencies>

创建被增强的类

// 被增强的类
public class User {
    //连接点/切入点
    public void add(){
        System.out.println("add......");
    }
    public void update(){
        System.out.println("update......");
    }
}

public class UserProxy {
    //增强/通知  ---》前置通知
    public void before(){
        System.out.println("before.............");
    }
}

  SpringConfig.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: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">
    <!--IOC管理bean-->
    <!--id:类的唯一标识符 class:类的全路径名-->
    <bean id="user" class="com.qcby.User"></bean>
    <bean id="userProxy" class="com.qcby.UserProxy"></bean>

    <!--配置切面-->
    <aop:config>
        <!--配置切面 = 切入点 + 通知组成-->
        <aop:aspect ref="userProxy">
            <!--前置通知：UserServiceImpl的save方法执行前，会增强-->
            <!--pointcut：后边是切入点表达式，作用是知道对对面的那个方法进行增强-->
            <aop:before method="before" pointcut="execution(public void com.qcby.User.add())"/>
        </aop:aspect>
    </aop:config>
</beans>

test测试

package com.qcby.test;

import com.qcby.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class DemoTest {
    @Test
    public void aopTest1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("SpringConfig.xml");
        User user = (User) applicationContext.getBean("user");
        user.add();
    }
}