springboot 發佈到 tomcat 7 啓動報錯：java.lang.NoClassDefFoundError: javax/el/ELManager

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/ELManager
 

原因： tomcat7中的el-api，版本太低，換成tomcat8即可