Spring AOP入门使用详解

大家好，又见面了，我是你们的朋友全栈君。

1.maven 依赖：

 <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <!--aop-->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.9</version>
        </dependency>

2.接口和实现定义

接口定义:

package com.aop.api;

/**
 * Created by zhangzh on 2016/8/5.
 */
public interface Service {
    public void save(String info);
}

接口实现:

package com.aop.impl;

import com.aop.api.Service;

/**
 * Created by zhangzh on 2016/8/5.
 */
public class ServiceImpl implements Service {
    public void save(String info) {
        System.out.println("save info:" + info);
    }
}

3.采用before和after方式进行切面操作:

切面类 

package com.aop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;

/**
 * Created by zhangzh on 2016/8/5.
 */
public class aspect {

    public void before(JoinPoint call) {

        String className = call.getTarget().getClass().getName();
        String methodName = call.getSignature().getName();
       Object[] args = call.getArgs();
        for(Object obj:args) {
            if(obj instanceof String) {
                System.out.println(methodName +"的执行参数为：" + obj);
            }
        }

        System.out.println("前置通知:" + className + "类的" + methodName + "开始执行了......");

    } 
    public void after() {
        System.out.println("最终通知:不管方法有没有正常执行完成，一定会返回的");
    }
}

aopContext.xml配置:

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns="http://www.springframework.org/schema/beans"
       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="service" class="com.aop.impl.ServiceImpl"/>
    <bean id="aspect" class="com.aop.aspect.aspect"/>

    <aop:config>
        <aop:aspect id="logAspect" ref="aspect">
            <aop:pointcut id="allMethod" expression="execution(* com.aop.api.Service.*(..))"/>
            <aop:before method="before" pointcut-ref="allMethod"/>
            <aop:after method="after" pointcut-ref="allMethod"/>
            <!--<aop:after-throwing method="afterThrowing" pointcut-ref="allMethod"/>-->
            <!--<aop:around method="doAround" pointcut-ref="allMethod"/>-->
        </aop:aspect>
    </aop:config>


</beans>

test类:

import com.aop.api.Service;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by zhangzh on 2016/8/5.
 */
public class AopTest {

    public static void main(String[] args) {

        ApplicationContext ac = new ClassPathXmlApplicationContext("META-INF/aopContext.xml");

        Service service = ac.getBean("service",Service.class); 
        service.save("### 1232536 #########");



    }
}

输出结果:

save的执行参数为：### 1232536 #########
前置通知:com.aop.impl.ServiceImpl类的save开始执行了......
save info:### 1232536 #########
最终通知:不管方法有没有正常执行完成，一定会返回的

4. 采用环绕aop配置:

切面类:

package com.aop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;

/**
 * Created by zhangzh on 2016/8/5.
 */
public class aspect {

    public void before(JoinPoint call) {

        String className = call.getTarget().getClass().getName();
        String methodName = call.getSignature().getName();
       Object[] args = call.getArgs();
        for(Object obj:args) {
            if(obj instanceof String) {
                System.out.println(methodName +"的执行参数为：" + obj);
            }
        }

        System.out.println("前置通知:" + className + "类的" + methodName + "开始执行了......");

    }

    public void afterReturn() {
        System.out.println("后置通知:方法正常结束了");
    }

    public void after() {
        System.out.println("最终通知:不管方法有没有正常执行完成，一定会返回的");
    }

    public void afterThrowing() {
        System.out.println("异常抛出后通知:方法执行时出异常了");
    }

    //用来做环绕通知的方法可以第一个参数定义为org.aspectj.lang.ProceedingJoinPoint类型
    public Object doAround(ProceedingJoinPoint call) throws Throwable {
        Object result = null;
        this.before(call);//相当于前置通知
        try {
            result = call.proceed();
            this.afterReturn(); //相当于后置通知
        } catch (Throwable e) {
            this.afterThrowing();  //相当于异常抛出后通知
            throw e;
        } finally {
            this.after();  //相当于最终通知
        }
        return result;
    }

}

aopContext.xml配置:

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns="http://www.springframework.org/schema/beans"
       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="service" class="com.aop.impl.ServiceImpl"/>
    <bean id="aspect" class="com.aop.aspect.aspect"/>

    <aop:config>
        <aop:aspect id="logAspect" ref="aspect">
            <aop:pointcut id="allMethod" expression="execution(* com.aop.api.Service.*(..))"/>
            <!--<aop:before method="before" pointcut-ref="allMethod"/>-->
            <!--<aop:after method="after" pointcut-ref="allMethod"/>-->
            <!--<aop:after-throwing method="afterThrowing" pointcut-ref="allMethod"/>-->
            <aop:around method="doAround" pointcut-ref="allMethod"/>
        </aop:aspect>
    </aop:config>


</beans>

test类:

import com.aop.api.Service;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by zhangzh on 2016/8/5.
 */
public class AopTest {

    public static void main(String[] args) {

        ApplicationContext ac = new ClassPathXmlApplicationContext("META-INF/aopContext.xml");

        Service service = ac.getBean("service",Service.class); 
        service.save("### 1232536 #########");



    }
}

输出结果:

save的执行参数为：### 1232536 #########
前置通知:com.aop.impl.ServiceImpl类的save开始执行了......
save info:### 1232536 #########
后置通知:方法正常结束了
最终通知:不管方法有没有正常执行完成，一定会返回的