Servlet.service() for servlet [dispatcherServlet] in 
context with path [] threw exception [Circular view path [abc]: would dispatch back to the current handler URL [/abc] again. 
Check your ViewResolver setup!
 (Hint: This may be the result of an unspecifiedview,
  due to default view name generation.)] with root cause

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

在springboot工程中 controller中写了返回值void报错

还可能是返回的视图解析器出现重复跳转的情况报错

可以将@Controller改为@RestController
同理也可以在方法上加上@Responsbody
都是让它不走视图解析器