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

In Spring AOP, you have to include the cglib library into your build path to avoid the “Cannot proxy target class because CGLIB2 is not available” error message.

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.mkyong.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

Solution

You can download the cglib library from …

1. Cglib official web site
http://cglib.sourceforge.net/

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

If you are using Maven, you can just include the Maven dependency.

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