上传文件 springboot 所需的请求部分“文件”不存在

Question

我想为我的 spring boot 应用程序添加一个上传功能；这是我上传的 Rest Controller

 package org.sid.web;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletContext;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.FileSystemResource;
import org.sid.entities.FileInfo;

@RestController
public class UploadController {
  @Autowired
  ServletContext context;

  @RequestMapping(value = "/fileupload/file", headers = ("content-type=multipart/*"), method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
  public ResponseEntity<FileInfo> upload(@RequestParam("file") MultipartFile inputFile) {
    FileInfo fileInfo = new FileInfo();
    HttpHeaders headers = new HttpHeaders();
    if (!inputFile.isEmpty()) {
      try {
        String originalFilename = inputFile.getOriginalFilename();
        File destinationFile = new File(
            context.getRealPath("C:/Users/kamel/workspace/credit_app/uploaded") + File.separator + originalFilename);
        inputFile.transferTo(destinationFile);
        fileInfo.setFileName(destinationFile.getPath());
        fileInfo.setFileSize(inputFile.getSize());
        headers.add("File Uploaded Successfully - ", originalFilename);
        return new ResponseEntity<FileInfo>(fileInfo, headers, HttpStatus.OK);
      } catch (Exception e) {
        return new ResponseEntity<FileInfo>(HttpStatus.BAD_REQUEST);
      }
    } else {
      return new ResponseEntity<FileInfo>(HttpStatus.BAD_REQUEST);
    }
  }
}

但是当在邮递员中插入 http://localhost:8082/fileupload/file 并将文件添加到正文中进行测试时，我得到了这个错误：“异常”： org.springframework.web.multipart.support.MissingServletRequestPartException", "message": "Required request part 'file' is not present ，

原文由 Wintern 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

这就是您在 Postman 中的请求应该是这样的：

我的示例代码：

应用程序.properties

 #max file and request size
spring.http.multipart.max-file-size=10MB
spring.http.multipart.max-request-size=11MB

主要应用类：

应用.java

 import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

休息控制器类：

 import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

    @Controller
    @RequestMapping("/fileupload")
    public class MyRestController {

    @RequestMapping(value = "/file", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE)
        public @ResponseBody String myService(@RequestParam("file") MultipartFile file,
                @RequestParam("id") String id) throws Exception {

    if (!file.isEmpty()) {

           //your logic
                        }
return "some json";

                }
    }

pom.xml

 //...

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

....

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web-services</artifactId>
</dependency>

//...

原文由 Tanmay Delhikar 发布，翻译遵循 CC BY-SA 3.0 许可协议

Answer 2

在您的方法中，您指定了这样的

@RequestParam("file") 。因此，它期望密钥为 file 。这在异常消息中非常明显。上传文件时，在 Postman 的 Key 字段中使用此名称。

更多信息在这里 集成测试用例和文件上传

原文由 pvpkiran 发布，翻译遵循 CC BY-SA 3.0 许可协议