@PathVariable是spring3.0的一个新功能：接收请求路径中占位符的值
@PutMapping(value = "/users/{userId}/unLock")
void unLock(@PathVariable("userId") String id, @RequestBody UnblockEvent unblockEvent) throws Exception {
userService.apply(unblockEvent);
}
id就是路径的userId值
原文：https://www.cnblogs.com/Sigmund-Freud-01/p/13851818.html