Spring AOP Error Cannot proxy target class because CGLIB2 is not available

在Spring AOP中，必須包括CGLIB包到構建路徑，以避免「Cannot proxy target class because CGLIB2 is not available」的錯誤訊息。

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerServiceProxy': FactoryBean threw exception on object creation; nested exception is org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available. Add CGLIB to the class path or specify proxy interfaces.
	at org.springframework.beans.factory.support.FactoryBeanRegistrySupport$1.run(FactoryBeanRegistrySupport.java:127)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:116)
	at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:91)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1288)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:217)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:880)
	at com.tw511.common.App.main(App.java:14)
Caused by: org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available. Add CGLIB to the class path or specify proxy interfaces.
	at org.springframework.aop.framework.DefaultAopProxyFactory.createAopProxy(DefaultAopProxyFactory.java:67)
	at org.springframework.aop.framework.ProxyCreatorSupport.createAopProxy(ProxyCreatorSupport.java:106)
	at org.springframework.aop.framework.ProxyFactoryBean.getSingletonInstance(ProxyFactoryBean.java:317)
	at org.springframework.aop.framework.ProxyFactoryBean.getObject(ProxyFactoryBean.java:243)
	at org.springframework.beans.factory.support.FactoryBeanRegistrySupport$1.run(FactoryBeanRegistrySupport.java:121)
	... 9 more

解決

可以從CGLIB包...

1. Cglib官方網站
http://cglib.sourceforge.net/

2. Maven資源庫
http://repo1.maven.org/maven2/cglib/cglib/2.2/

如果使用Maven，可以只包括 Maven 依賴。

<!-- AOP dependency -->
    <dependency>
    	<groupId>cglib</groupId>
	<artifactId>cglib</artifactId>
	<version>2.2</version>
    </dependency>