spirng aop xml配置類型轉換異常

場景：一場表演（Performance.perform())前后的觀眾行為（Audience類中定義的方法）

下面是Audience類的定義

package com.kylin.springaop.xml;

public class Audience {
    public void seatDown(){
        System.out.println("seat down");
    }

    public void claps(){
        System.out.println("claps claps claps");
    }

    public void returned(){
        System.out.println("returned");
    }

    public void exception(){
        System.out.println("exception");
    }
}

下面是Performance類

package com.kylin.springaop.xml;

public class Performance {
    public void performance(){
        System.out.println("perform");
    }
}

下面是xml配置

<?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="audience" class="com.kylin.springaop.xml.Audience"/>
    <bean id="performance" class="com.kylin.springaop.xml.Performance"/>

    <!--
        下面聊一個巨坑的東西镊叁，如果切點Bean的id和pointcut的id相同的話柒昏，就會出現
        Exception in thread "main" java.lang.ClassCastException:
        org.springframework.aop.aspectj.AspectJExpressionPointcut cannot be cast to com.kylin.springaop.xml.Performance
        spring將會認為上面配置的Bean是一個切點，然而切點是Bean中的perform()方法，就會出現
        類型轉換異常。
    -->
    <!--錯誤配置，pointcut的id不能和Bean的id相同
    <aop:config>
        <aop:aspect ref="audience">
            <aop:pointcut id="performance"
                          expression="execution(* com.kylin.springaop.xml.Performance.performance(..))"/>
            <aop:before method="seatDown" pointcut-ref="performance"/>
            <aop:after method="claps" pointcut-ref="performance"/>
            <aop:after-returning method="returned" pointcut-ref="performance"/>
            <aop:after-throwing method="exception" pointcut-ref="performance"/>
        </aop:aspect>
    </aop:config>
    -->
    <aop:config>
        <aop:aspect ref="audience">
            <aop:pointcut id="perform"
                          expression="execution(* com.kylin.springaop.xml.Performance.performance(..))"/>
            <aop:before method="seatDown" pointcut-ref="perform"/>
            <aop:after method="claps" pointcut-ref="perform"/>
            <aop:after-returning method="returned" pointcut-ref="perform"/>
            <aop:after-throwing method="exception" pointcut-ref="perform"/>
        </aop:aspect>
    </aop:config>
</beans>

總的來說切點的id不能和bean的id相同。