如果参数不存在，Spring 4.1.5 MVC @RequestParam(required = false, value = "somevalue") 将失败

我有一个 spring mvc 控制器，它正在为具有多个请求参数的 Web 服务请求提供服务。所有参数均已标注required = false。如果请求中的参数不可用，

@RequestMapping(value = "/service/deployNew", method = RequestMethod.POST)
@ResponseBody public ResponseEntity<DeploymentId>  deploy(HttpServletRequest request, HttpServletResponse response, @RequestParam(required = false, value = "abc") String abc, @RequestParam(required = false, value = "xyz") String xyz, @RequestParam(required = false, value = "uvw") String uvw,)  throws Exception;

我看到错误

required string parameter 'param' is not present

如果我给参数赋予空白值，则一切正常，如下所示。参数abc and xyz有一个空白值，但我仍然通过它。

curl -i -X POST -H Accept:application/json "http://localhost:8080/Test/service/deploy.do?abc=&xyz=&uvw=somevalue"

如果我删除上述任何参数，它将引发错误。

curl -i -X POST -H Accept:application/json "http://localhost:8080/Test/service/deploy.do?uvw=somevalue"

我的服务由具有单个端点的多个客户端使用，这导致有时会出现一些参数。我需要处理所有的场景。任何想法？

尝试使用默认值

@RequestParam(required = false, defaultValue = "somevalue")

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RequestParam.html#defaultValue-- https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/RequestParam.html#defaultValue--