FileSystemResource to MultipartFile - spring

Question

I want to send my image from my storage using the path like this:
MultiValueMap<String, Object> image = new LinkedMultiValueMap<String, Object>();
image.add("image", new FileSystemResource("C:\\xx\\xx\\xx\\xx\\xx\\xx\\xx\\img\\xx.jpg"));
so I call the object using the code below:
MultiValueMap<String, Object> body = new LinkedMultiValueMap<String,Object>();
body.add("image", image);
Then, I get this error:
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class sun.nio.ch.ChannelInputStream]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class sun.nio.ch.ChannelInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: org.springframework.util.LinkedMultiValueMap["image"]->java.util.LinkedList[0]->org.springframework.core.io.FileSystemResource["inputStream"])] with root cause
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class sun.nio.ch.ChannelInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: org.springframework.util.LinkedMultiValueMap["image"]->java.util.LinkedList[0]->org.springframework.core.io.FileSystemResource["inputStream"])
I am using the Rest Template of spring boot, which requires me to send by POST Method the MultipartFile object. Now, I do not know how to convert into the MultipartFile type,
so the Rest Template can accept my request post.
Note: I want to use the body.add("image", image.getResource()); but It did not show up in selection since image wasn't of MultipartFile type.

Answer 1

This worked for me.
#GetMapping(path = "/copy", produces = MediaType.TEXT_PLAIN_VALUE)
public ResponseEntity<String> copyFile() {
MultiValueMap<String, Object> body
= new LinkedMultiValueMap<>();
body.add("image", new FileSystemResource("test.jpg"));
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
HttpEntity<MultiValueMap<String, Object>> requestEntity
= new HttpEntity<>(body, headers);
String serverUrl = "http://localhost:8080/upload";
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate
.postForEntity(serverUrl, requestEntity, String.class);
return response;
}
#PostMapping(path = "/upload", produces = MediaType.TEXT_PLAIN_VALUE)
public String uploadFile(#RequestParam("image") MultipartFile file) {
try {
byte[] bytes = file.getBytes();
Path path = Paths.get("./uploadedImages/" + file.getOriginalFilename());
Files.write(path, bytes);
} catch (IOException e) {
e.printStackTrace();
return "Error";
}
return "File Uploaded";
}