Circular view path [index]: would dispatch back to the current handler URL [/index] again.

错误信息

javax.servlet.ServletException: Circular view path [index]: would dispatch back to the current handler URL [/index] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.)

原因

使用Thymeleaf模板时，引入了：

<dependency>
      <groupId>org.thymeleaf</groupId>
      <artifactId>thymeleaf</artifactId>
</dependency>

解决

应该引入：

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