Postman: Required request part 'file' is n

问题:

I wanted to upload an image to my Rest API through postman. I am using spring boot framework. Here is the screen shot:

I also have not set any any headers as I found in other stack overflow answers that it gives multipart boundary error.

Now, below is my controller code:

package com.practice.rest.assignment1.controller;

import java.io.IOException;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
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.RestController;
import org.springframework.web.multipart.MultipartFile;
import com.practice.rest.assignment1.model.Product;
import com.practice.rest.assignment1.service.CatalogueService;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;

@RestController
@RequestMapping("/CatalogueController/")
public class CatalogueController{

    @Autowired
    private CatalogueService catalogueService;

    @RequestMapping(value = "addProduct", method = RequestMethod.POST , consumes = "multipart/form-data")
    public Product addProduct(@RequestParam String productJson, @RequestParam MultipartFile file) throws JsonParseException, JsonMappingException, IOException {


        Product product = new ObjectMapper().readValue(productJson, Product.class);
        byte[] mediaBytes = file.getBytes();
        product.setImage(mediaBytes);
        return catalogueService.saveInDb(product);

    }

}

Now, I am taking a Product object which consists internally an image defined as byte[] array. I take this as string and image separately as Multipart file.

Below is my product class attributes defined :

    private Long pId;
    private String model;
    private String brand;
    private byte[] image; // This is where I want the image to save
    private Long price;
    private String currency;
    private String transmissionType;
    private String fuelType;

Since , I am using spring boot , here is my Main class :

package com.practice.rest.assignment1;

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


@SpringBootApplication
public class App {

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

}

The error on postman I get is :

{
  "timestamp": 1478611635977,
  "status": 400,
  "error": "Bad Request",
  "exception": "org.springframework.web.multipart.support.MissingServletRequestPartException",
  "message": "Required request part 'file' is not present",
  "path": "/CatalogueController/addProduct"
}

Where am I wrong ?

回答1:

I think the problem lies in the JSON parameter you are sending. In postman you don't need to put the starting and trailing " to represent a parameter as string. And also if you use starting and ending " then inside the JSON( mean for JSON object the properties key and value) you should use '(single quote).

回答2:

Try remove 'Content-Type: multipart/form-data...', section of the headers. It solved this for me.

回答3:

Hi @Breaking Benjamin I did a same demo, and there is my post request copy:

curl 'http://localhost:9999/api/v1/upload' -H 'Pragma: no-cache' -H 'Origin: chrome-extension://fdmmgilgnpjigdojojpjoooidkmcomcm' -H 'Accept-Encoding: gzip, deflate, br' -H 'Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.6,en;q=0.4' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36' -H 'Content-Type: multipart/form-data; boundary=----WebKitFormBoundary0ae4CymwYLjdqdI1' -H 'Accept: */*' -H 'Cache-Control: no-cache' -H 'Cookie: _ga=GA1.1.433565887.1474948752' -H 'Connection: keep-alive' -H 'DNT: 1' --data-binary $'------WebKitFormBoundary0ae4CymwYLjdqdI1\r\nContent-Disposition: form-data; name="file"; filename="228cb73.jpg"\r\nContent-Type: image/jpeg\r\n\r\n\r\n------WebKitFormBoundary0ae4CymwYLjdqdI1\r\nContent-Disposition: form-data; name="a"\r\n\r\n123\r\n------WebKitFormBoundary0ae4CymwYLjdqdI1--\r\n' --compressed

And, my upload controller is written like this:

@RequestMapping(method = RequestMethod.POST)
    public ResponseEntity handleUpload(
            @RequestParam("a")String a,
            @RequestParam("file") MultipartFile multipartFile) throws IOException {

        System.out.println(a);
        ...

In my console, the param a is successfully output:

Even if I use a json string to send request again:

curl 'http://localhost:9999/api/v1/upload' -H 'Pragma: no-cache' -H 'Origin: chrome-extension://fdmmgilgnpjigdojojpjoooidkmcomcm' -H 'Accept-Encoding: gzip, deflate, br' -H 'Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.6,en;q=0.4' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36' -H 'Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryBTudL55M6S8ENLVt' -H 'Accept: */*' -H 'Cache-Control: no-cache' -H 'Cookie: _ga=GA1.1.433565887.1474948752' -H 'Connection: keep-alive' -H 'DNT: 1' --data-binary $'------WebKitFormBoundaryBTudL55M6S8ENLVt\r\nContent-Disposition: form-data; name="file"; filename="228cb73.jpg"\r\nContent-Type: image/jpeg\r\n\r\n\r\n------WebKitFormBoundaryBTudL55M6S8ENLVt\r\nContent-Disposition: form-data; name="a"\r\n\r\n"{"key":"value"}"\r\n------WebKitFormBoundaryBTudL55M6S8ENLVt--\r\n' --compressed

It's looks your code is ok, but would you try to use curl to send a request again, maybe this is because you bad usage of postman.

回答4:

For me it worked to set these variables in application.properties:

spring.http.multipart.enabled=true 
spring.http.multipart.location= /upload

回答5:

For me updating my application.properties by updating variable worked spring.http.multipart.enabled=true

My service is

@PostMapping(value = "/console")
public ResponseEntity<RxConsoleDTO> addRxConsole(@RequestParam("attachment") MultipartFile attachmentFile,  @RequestParam("type") String type) throws IOException {// your logic}

回答6:

Also check if the below property is enabled and if we are uploading a text file it won't consider as proper parameter.

upload.file.extensions=jpg, jpeg, gif, png