报错：Feign PathVariable annotation was empty on param 0.

错误出现原因：
使用Feign的时候,如果参数中带有@PathVariable形式的参数,则要用value=""标明对应的参数,否则会抛出IllegalStateException异常。

错误示范：
@PostMapping(value = “/group/{workspace}”)
String publishLayerGroup(@PathVariable String workspace);

正确方式：
@PostMapping(value = “/group/{workspace}”)
String publishLayerGroup(@PathVariable(value=“workspace”) String workspace);