springboot整合thymeleaf报错 NoClassDefFoundError: org/thymeleaf/spring5/view/ThymeleafViewResolver

报错的原因是

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-thymeleaf</artifactId>
   <version>1.4.3.RELEASE</version>
</dependency>

的版本与parent（如下）的版本不一样

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>2.0.1.RELEASE</version>
   <relativePath/> <!-- lookup parent from repository -->
</parent>

解决方法是去掉spring-boot-starter-thymeleaf的版本号重新reimport就可以了，如下

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>