how to send MultiValueMap containing a file in a POST request to Spring rest web service?

Question

I want to send a POST request which includes a file and another custom object using restTemplate. I have tried the code below, but didn't get it working as it is missing an `HtttpMessageConverter` for `java.io.File` Is MultiValueMap the right choice to send both objects in one request? If not, any suggestions? If yes, then how do I get the message converter problem solved? The client (adopted from here and here): ``` RestTemplate rest = new RestTemplate(); HttpMessageConverter formHttpMessageConverter = new FormHttpMessageConverter(); HttpMessageConverter stringHttpMessageConverternew = new StringHttpMessageConverter(); List> conv = new ArrayList> (); conv.add(formHttpMessageConverter); conv.add(stringHttpMessageConverternew); rest.setMessageConverters(conv); MultiValueMap map = new LinkedMultiValueMap(); File f = new File("testFile.txt"); map.add("file", f); NewObject a = new NewObject("123", "xxx", "xxx"…

Accepted Answer

I spend so much time on this error!

FormHttpMessageConverter has 3 converters for parts:

- ByteArrayHttpMessageConverter - writes byte[].class

- StringHttpMessageConverter - String.class

- ResourceHttpMessageConverter - org.springframework.core.io.Resource.class - here is the trick

Instead of putting file itself, you should put it as Resource:

```
File file = new File("some_path");
Resource resource = new FileSystemResource(file);
map.add("file", resource);
```

FileSystemResource is from package org.springframework.core.io

how to send MultiValueMap containing a file in a POST request to Spring rest web service?

Solution

Problem