一. 项目启动不起来

很奇怪在另一台电脑可以，但是换了一台电脑就不行了，两台电脑的区别仅仅是idea编辑器不一样，一个是社区版，一个是专业版。

  1. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'discoveryLocatorProperties' defined in class path resource [org/springframework/cloud/gateway/discovery/GatewayDiscoveryClientAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties]: Factory method 'discoveryLocatorProperties' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/validation/ValidationException
  3. Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties]: Factory method 'discoveryLocatorProperties' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/validation/ValidationException
  5. Caused by: java.lang.NoClassDefFoundError: javax/validation/ValidationException

解决方案：根据 Spring Boot 2.3 Release Notes ，Validation Starter不再包含在Web Start中，所以需要我们额外的引入Validation的依赖包。2.3版本以后Validation Starter不再包含在Web Start中，得额外引入：

  1. <dependency>
  2.   <groupId>org.springframework.boot</groupId>
  3.   <artifactId>spring-boot-starter-validation</artifactId>
  4. </dependency>