问题描述：
SpringBoot项目 tomcat插件启动出现下面的问题：
ERROR -04-07 08:42:03,129 org.springframework.boot.SpringApplication[837] -> Application run failedorg.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultValidator' defined in class path resource [org/springframework/boot/autoconfigure/validation/ValidationAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.validation.beanvalidation.LocalValidatorFactoryBean]: Factory method 'defaultValidator' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/el/ELManagerat org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:591)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1246)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1096)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:535)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495)at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759)at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)at org.springframework.context.support.AbstractApplicationContext.__refresh(AbstractApplicationContext.java:548)at org.springframework.context.support.AbstractApplicationContext.jrLockAndRefresh(AbstractApplicationContext.java:40002)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:41008)at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:386)at org.springframework.boot.SpringApplication.run(SpringApplication.java:307)at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:157)at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:137)at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:172)at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5423)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)at java.util.concurrent.FutureTask.run(FutureTask.java:266)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)at java.lang.Thread.run(Thread.java:745)Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.validation.beanvalidation.LocalValidatorFactoryBean]: Factory method 'defaultValidator' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/el/ELManagerat org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:583)... 29 moreCaused by: java.lang.NoClassDefFoundError: javax/el/ELManagerat org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.buildExpressionFactory(ResourceBundleMessageInterpolator.java:88)at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.<init>(ResourceBundleMessageInterpolator.java:47)at org.hibernate.validator.internal.engine.ConfigurationImpl.getDefaultMessageInterpolator(ConfigurationImpl.java:474)at org.springframework.boot.validation.MessageInterpolatorFactory.getObject(MessageInterpolatorFactory.java:54)at org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration.defaultValidator(ValidationAutoConfiguration.java:57)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.__invoke(DelegatingMethodAccessorImpl.java:43)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45009)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45012)at java.lang.reflect.Method.invoke(Method.java:497)at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)... 30 more
根据报错的显示我们知道是缺少具体的class ： javax/el/ELManager
我看很多问题网上解决方案是
1.改变tomcat7 升级为tomcat8，
2. 换tomcat插件中相关的jar
但是我是在本地ecplise中运行的，使用的是tomcat7 2.2的插件
<plugin><groupId>org.apache.tomcat.maven</groupId><artifactId>tomcat7-maven-plugin</artifactId><version>2.2</version><configuration><port>8082</port><path>/aisinoboot</path></configuration></plugin>
上面的两种解决对我当前的启动方式来说都不是一个最佳的方案
其实问题根源在 hibernate-validator .jar 的版本太高导致的,我们来看这个jar包的版本
6.0 这个版本太高了
我们可以在引用spring-boot-starter-web的时候，把这个jar除外
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-logging</artifactId></exclusion><exclusion><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId></exclusion><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-tomcat</artifactId></exclusion><exclusion><groupId>org.hibernate.validator</groupId><artifactId>hibernate-validator</artifactId></exclusion></exclusions></dependency>
然后单独的引用，在maven仓库中最低的版本是6.0.0
这个版本还是比较高的
我们可以在网上下载比较低的版本，然后放进lib 进行build Path
这样重新启动项目，问题解决
希望对你有所帮助
