在Spring MVC中处理Multipart和非多部分HTTP POST

Question

我有一个用于上传文件的SpringMVC Web服务,如下所示:

@RequestMapping(value="/upload.json", method = RequestMethod.POST)
public @ResponseBody Map<String, Object> upload(MultipartHttpServletRequest request) {
    // upload the file
}

一切都很花花公子.但是如果其中一个消费者发布了非多部分表单,那么我会得到这个例外

java.lang.IllegalStateException: Current request is not of type [org.springframework.web.multipart.MultipartHttpServletRequest]

这是有道理的..但是我不希望我的最终用户看到500个servlet异常.我想要一个友好的错误消息.

我刚试过这个(就像其他POST一样):

@RequestMapping(value="/upload.json", method = RequestMethod.POST)
public @ResponseBody Map<String, Object> upload2(){ 
// return friendly msg 
}

但我得到这个错误:

java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path '/upload.json'

有没有办法安全地处理多部分和非多部分POST请求？在一种方法,或2种不同的方法,我不在乎.

Answer 1

检查请求是否是自己的多部分:

@RequestMapping(value="/upload.json", method = RequestMethod.POST) 
public @ResponseBody Map<String, Object> upload(HttpServletRequest request) {
    if (request instanceof MultipartHttpServletRequest) {
        // process the uploaded file
    }
    else {
        // other logic
    }
}