处理multipart/form-data请求时，srpingboot 1.3.7中的文件始终为空

Question

我正在尝试将grails应用程序与springboot应用程序进行通信。我正在尝试将一个文件上载到springboot应用程序，该文件之前已上载到grails。这是我的springboot控制器的代码：

@ResponseBody
    @PostMapping(value = "/save", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    def save(@Valid @ModelAttribute SaveRequest request) {
        //Some logic
}

saveRequest类包含一些需要应用于请求的验证

class SaveHotelAccreditationRequest {

    //Other fields

    @NotNull
    MultipartFile image

}

我已经在应用程序中设置了属性。像这样的属性文件

spring.http.multipart.enabled = true
spring.http.multipart.location=/home/user/temp

我使用Apache的commons io和commons fileupload库。我已经这样设置了多部分解析器

@Bean(name = "multipartResolver")
public CommonsMultipartResolver multipartResolver() {
    CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
    multipartResolver.setMaxUploadSize(2*1024*1024);
    return multipartResolver;
}

这是我的grails应用程序中的代码

CredentialsProvider credsProvider = new BasicCredentialsProvider()
    credsProvider.setCredentials(
            AuthScope.ANY,
            new UsernamePasswordCredentials(userName, password))
    CloseableHttpClient httpclient = HttpClients.custom()
            .setDefaultCredentialsProvider(credsProvider)
            .build()
    try {
        HttpPost httpPost = new HttpPost(url)
        MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create()
        reqEntity.setMode(HttpMultipartMode.BROWSER_COMPATIBLE)
        reqEntity.addBinaryBody('image', file, ContentType.MULTIPART_FORM_DATA, file.getName())
        //Other fields
        httpPost.setEntity(reqEntity.build())
        System.out.println("Executing request " + httpPost.getRequestLine())
        CloseableHttpResponse response = httpclient.execute(httpPost)
        try {
            System.out.println("----------------------------------------")
            System.out.println(response.getStatusLine())
            System.out.println(EntityUtils.toString(response.getEntity()))
        } finally {
            response.close()
        }
    } finally {
        httpclient.close()
    }

当我运行请求时，会收到以下错误消息：

2020-05-02 02:37:24 | WARN | org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Resolved
 exception caused by Handler execution: org.springframework.validation.BindException: org.springframework.validatio
n.BeanPropertyBindingResult: 1 errors
Field error in object 'saveHotelAccreditationRequest' on field 'image': rejected value [null]; codes [NotNull.saveRequest.image,NotNull.image,NotNull.org.springframework.web.multipart.MultipartFile,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [saveRequest.image,image]; arguments []; default message [image]]; default message [may not be null]

我尝试过使用postman，但收到了相同的错误消息。我不知道我在这里遗漏了什么，任何帮助都将不胜感激。

Answer 1

在使用Multipart时，以下内容在Spring Boot中为我工作。

@PostMapping(value = "/uploadVideo")
public void uploadVideo(HttpServletRequest request, HttpServletResponse response,
            @RequestParam("file") MultipartFile file) throws Exception {
    // logic here
}

并且您用于最大大小的多部分解析器可以在这样的属性文件中配置

# Max file size.
spring.servlet.multipart.max-file-size=200MB
# Max Request Size
spring.servlet.multipart.max-request-size=215MB

这是我从Angular应用程序调用的

var reqHeader=new HttpHeaders();
    reqHeader.append('contentType','multipart/form-data')
    let options = { headers: reqHeader, params: new HttpParams()
                          
                   };
    const formData = new FormData();
    formData.append('file', file )
    return this.http.post(this.url_toreadFile,formData,options)

希望它能为您的实现提供一些帮助。

Answer 2

在Spring Boot REST for multipart API中，我编写的多部分API如下

@PostMapping("/upload-doc")
@ApiImplicitParam(paramType = "body", name = "payload", dataType = "UploadDocRequest")
@ResponseStatus(HttpStatus.CREATED)
@ApiOperation("Upload User's documents")
public UploadDocRequest uploadDocRequest(
        @RequestPart("payload") UploadDocRequest payload, @RequestPart("docs") MultipartFile[] docs) {

yaml中的Spring Multipart配置

spring:
 servlet:
  multipart:
   max-file-size: 5MB
   max-request-size: 5MB