警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userInfoService' defined in file [E:\MyProject\MavenProject\testdemo\target\classes\com\young\service\UserInfoService.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class com.young.service.UserInfoService: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class com.young.service.UserInfoService

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userInfoService' defined in file [E:\MyProject\MavenProject\testdemo\target\classes\com\young\service\UserInfoService.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class com.young.service.UserInfoService: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class com.young.service.UserInfoService

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
	at TestAOP.testAOP(TestAOP.java:13)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class com.young.service.UserInfoService: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class com.young.service.UserInfoService
	at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:208)
	at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:110)
	at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.createProxy(AbstractAutoProxyCreator.java:471)
	at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:350)
	at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:299)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:429)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593)
	... 33 more
Caused by: java.lang.IllegalArgumentException: Cannot subclass final class com.young.service.UserInfoService
	at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:657)
	at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)
	at org.springframework.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
	at org.springframework.aop.framework.CglibAopProxy$ClassLoaderAwareUndeclaredThrowableStrategy.generate(CglibAopProxy.java:1007)
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:358)
	at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:582)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:110)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:108)
	at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:134)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:319)
	at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:569)
	at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:416)
	at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:57)
	at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:205)
	... 40 more


Process finished with exit code -1

首先第一次看到这么一大串异常我的内心是奔溃的，因为对于小白的我来说，它并没有给我指出哪行代码错误
在第一次出现该异常时，我通过更换导入的jar包版本解决了问题，对于jar包版本的使用，一定要选择与开发环境契合的，比如spring-context这个jar包选择的是5.1.9.RELEASE这个版本，那么选择其他Spring框架jar包最好也选择该版本，可以避免因为jar包的版本不契合而出错。
这是我第二次见到这个异常，我不管怎么修改jar包的版本都是报这样的错误，然后我就在网上查找，网上说当使用AOP时，被代理的类不能用final修饰，我根本没有用final修饰userInfoService这个类，后来我在查看代码时，不知道为什么，userInfoService这个类被final修饰了（应该是自己没注意吧）…

如果之后遇到这类的异常，要学会去读异常，尤其要注意Caused by后面的语句

Exception encountered during context initialization
比如这句翻译过来的意思就是，xml配置问及解析的时候出现了异常
Could not generate CGLIB subclass of class com.young.service.UserInfoService
这句的意思就是无法通过CGLIB代理创建UserInfoService的代理类
Caused by: java.lang.IllegalArgumentException: Cannot subclass final class com.young.service.UserInfoService
这句的意思就是无法子类化被final修饰的UserInfoService类

通过对异常代码的阅读与分析就可以缩短解决问题的时间