Converting File to MultiPartFile

Is there any way to convert a File object to MultiPartFile? So that I can send that object to methods that accept the objects of MultiPartFile interface?

File myFile = new File("/path/to/the/file.txt")

MultiPartFile ....?

def (MultiPartFile file) {
  def is = new BufferedInputStream(file.getInputStream())
  //do something interesting with the stream
}

Solution 1:

MockMultipartFile exists for this purpose. As in your snippet if the file path is known, the below code works for me.

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.springframework.mock.web.MockMultipartFile;

Path path = Paths.get("/path/to/the/file.txt");
String name = "file.txt";
String originalFileName = "file.txt";
String contentType = "text/plain";
byte[] content = null;
try {
    content = Files.readAllBytes(path);
} catch (final IOException e) {
}
MultipartFile result = new MockMultipartFile(name,
                     originalFileName, contentType, content);

Solution 2:

File file = new File("src/test/resources/input.txt");
FileInputStream input = new FileInputStream(file);
MultipartFile multipartFile = new MockMultipartFile("file",
            file.getName(), "text/plain", IOUtils.toByteArray(input));

Solution 3:

MultipartFile multipartFile = new MockMultipartFile("test.xlsx", new FileInputStream(new File("/home/admin/test.xlsx")));

This code works fine for me. May be you can have a try.

Solution 4:

In my case, the

fileItem.getOutputStream();

wasn't working. Thus I made it myself using IOUtils,

File file = new File("/path/to/file");
FileItem fileItem = new DiskFileItem("mainFile", Files.probeContentType(file.toPath()), false, file.getName(), (int) file.length(), file.getParentFile());

try {
    InputStream input = new FileInputStream(file);
    OutputStream os = fileItem.getOutputStream();
    IOUtils.copy(input, os);
    // Or faster..
    // IOUtils.copy(new FileInputStream(file), fileItem.getOutputStream());
} catch (IOException ex) {
    // do something.
}

MultipartFile multipartFile = new CommonsMultipartFile(fileItem);

Solution 5:

This is a solution without creating manually a file on disc :

MultipartFile fichier = new MockMultipartFile("fileThatDoesNotExists.txt",
            "fileThatDoesNotExists.txt",
            "text/plain",
            "This is a dummy file content".getBytes(StandardCharsets.UTF_8));