再次分析-提出 Spring AOP-真正的AOP

public interface SmartAnimalable {
    //求和
    float getSum(float i, float j);
    //求差
    float getSub(float i, float j);
}

@Component //使用@Component 当spring容器启动时，将 SmartDog注入到容器
public class SmartDog implements SmartAnimalable {
    @Override
    public float getSum(float i, float j) {
        float result = i + j;
        //result = 1 / 0; //模拟一个算术异常
        System.out.println("方法内部打印result = " + result);
        return result;
    }
    @Override
    public float getSub(float i, float j) {
        float result = i - j;
        System.out.println("方法内部打印result = " + result);
        return result;
    }
}

@Aspect //表示是一个切面类[底层切面编程的支撑(动态代理+反射+动态绑定...)]
@Component //会注入SmartAnimalAspect到容器
public class SmartAnimalAspect {
 /**
     * 
     * 1. @Before 表示前置通知:即在我们的目标对象执行方法前执行
     * 2. value = "execution(public float com.spring.aop.aspectj.SmartDog.getSum(float, float)
     * 指定切入到哪个类的哪个方法  形式是: 访问修饰符 返回类型 全类名.方法名(形参列表)
     * 3. showBeginLog方法可以理解成就是一个切入方法, 这个方法名是可以程序员指定  比如:showBeginLog
     * 4. JoinPoint joinPoint 在底层执行时，由AspectJ切面框架， 会给该切入方法传入 joinPoint对象
     * , 通过该方法，程序员可以获取到 相关信息
     *
     * @param joinPoint
     */
    @Before(value = "execution(public float com.spring.aop.aspectj.SmartDog.getSum(float, float))")
    public void showBeginLog(JoinPoint joinPoint) {
        //通过连接点对象joinPoint 可以获取方法签名
        Signature signature = joinPoint.getSignature();
        System.out.println("SmartAnimalAspect-切面类showBeginLog()[使用的myPointCut()]-方法执行前-日志-方法名-" + signature.getName() + "-参数 "
                + Arrays.asList(joinPoint.getArgs()));
    }
    // 返回通知：即把showSuccessEndLog方法切入到目标对象方法正常执行完毕后的地方
    // 1. 如果我们希望把目标方法执行的结果，返回给切入方法
    // 2. 可以再 @AfterReturning 增加属性 , 比如 returning = "res"
    // 3. 同时在切入方法增加 Object res
    // 4. 注意: returning = "res" 和 Object res 的 res名字一致
    // @AfterReturning(value = "execution(public float com.spring.aop.aspectj.SmartDog.getSum(float, float))", returning = "res")
    // 使用切入点
    @AfterReturning(value = "execution(public float com.hspedu.spring.aop.aspectj.SmartDog.getSum(float, float))", returning = "res")
    public void showSuccessEndLog(JoinPoint joinPoint, Object res) {
        Signature signature = joinPoint.getSignature();
        System.out.println("SmartAnimalAspect-切面类showSuccessEndLog()-方法执行正常结束-日志-方法名-" + signature.getName() + " 返回的结果是=" + res);
    }
    //异常通知：即把showExceptionLog方法切入到目标对象方法执行发生异常的的catch{}
    @AfterThrowing(value = "execution(public float com.spring.aop.aspectj.SmartDog.getSum(float, float))", throwing = "throwable")
    public void showExceptionLog(JoinPoint joinPoint, Throwable throwable) {
        Signature signature = joinPoint.getSignature();
        System.out.println("SmartAnimalAspect-切面类showExceptionLog()-方法执行异常-日志-方法名-" + signature.getName() + " 异常信息=" + throwable);
    }
    //最终通知：即把showFinallyEndLog方法切入到目标方法执行后(不管是否发生异常,都要执行 finally{})
    @After(value = "execution(public float com.spring.aop.aspectj.SmartDog.getSum(float, float))")
    public void showFinallyEndLog(JoinPoint joinPoint) {
        Signature signature = joinPoint.getSignature();
        System.out.println("SmartAnimalAspect-切面类showFinallyEndLog()-方法最终执行完毕-日志-方法名-" + signature.getName());
    }
}

<?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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
    <context:component-scan
            base-package="com.spring.aop.aspectj"/>
    <!-- 开启基于注解的AOP功能 -->
    <aop:aspectj-autoproxy/>
</beans>

@Test
    public void testDoAround() {
        //得到spring容器
        ApplicationContext ioc =
                new ClassPathXmlApplicationContext("beans08.xml");
        SmartAnimalable smartAnimalable =
                ioc.getBean(SmartAnimalable.class);
        smartAnimalable.getSum(10, 2);
    }