编写第二个Spring程序——AOP实现

第二个Spring程序 AOP范例

1、新建maven工程

2、在pom.xml文件导入相关jar包

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.1.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.2.1.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.1.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-api -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.6.2</version>
            <scope>test</scope>
        </dependency>
				<!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>compile</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
            <scope>runtime</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjrt -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.9.6</version>
        </dependency>

3、在 Packge【service】下创建 【ProductService】类：

package service;

public class ProductService {
    
    
    public void doSomeService(){
    
    
        System.out.println("doSomeService");
    }
}

4、在 xml 文件中装配该 bean：

<bean name="productService" class="service.ProductService" />

5、在【TestSpring】中编写测试代码，运行：

package test;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import pojo.Source;
import service.ProductService;

public class TestSpring {
    
    

    @Test
    public void test(){
    
    
        ApplicationContext context = new ClassPathXmlApplicationContext(
                new String[]{
    
    "applicationContext.xml"}
        );

        ProductService productService = (ProductService) context.getBean("productService");
        productService.doSomeService();

    }
}

运行结果

doSomeService

6、在 Packge【aspect】下准备日志切面 【LoggerAspect】类：

package aspect;

import org.aspectj.lang.ProceedingJoinPoint;

public class LoggerAspect {
    
    
    
    public Object log(ProceedingJoinPoint joinPoint) throws Throwable {
    
    
        System.out.println("start log:" + joinPoint.getSignature().getName());
        Object object = joinPoint.proceed();
        System.out.println("end log:" + joinPoint.getSignature().getName());
        return object;
    }
}

7、在 xml 文件中声明业务对象和日志切面：

<?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"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
   http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/aop
   http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
   http://www.springframework.org/schema/tx
   http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <bean name="productService" class="service.ProductService" />
    <bean id="loggerAspect" class="aspect.LoggerAspect"/>

    <!-- 配置AOP -->
    <aop:config>
        <!-- where：在哪些地方（包.类.方法）做增加 -->
        <aop:pointcut id="loggerCutpoint"
                      expression="execution(* service.ProductService.*(..)) "/>

        <!-- what:做什么增强 -->
        <aop:aspect id="logAspect" ref="loggerAspect">
            <!-- when:在什么时机（方法前/后/前后） -->
            <aop:around pointcut-ref="loggerCutpoint" method="log"/>
        </aop:aspect>
    </aop:config>
</beans>

8、再次运行 TestSpring 中的测试代码，代码并没有改变，但是在业务方法运行之前和运行之后，都分别输出了日志信息：

start log:doSomeService
doSomeService
end log:doSomeService