Converting File to MultiPartFile with spring

Question

I want to convert File to multipartfile with spring. I have make this:

File in;
MultipartFile file =  null;
in = new File("C:...file on disk");
int size = (int) in.length();
DiskFileItem fileItem = new DiskFileItem("file", "application/vnd.ms-excel", false, nomefile, size ,in.getAbsoluteFile());
file = new CommonsMultipartFile(fileItem);

but receive this exception:

threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at org.apache.commons.fileupload.disk.DiskFileItem.getSize(DiskFileItem.java:316)

i think that fileItem is null but on debug mode is populated, there is another solution? I have this post Converting File to MultiPartFile but not work and not have solution.

Possible duplicate of [Converting File to MultiPartFile](http://stackoverflow.com/questions/16648549/converting-file-to-multipartfile) — Georgios Syngouroglou, Apr 20 '17 at 12:05

score 17 · Answer 1 · answered Jun 02 '15 at 05:30

17

    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));

This is another way of getting multipart file from File object

answered Jun 02 '15 at 05:30

Anoop George

742
6
6

1

I'd like to point out that MockMultipartFile is in **org.springframework.mock.web**. And, this works nicely. – Paul Cuddihy Mar 28 '17 at 18:18
2

it only works in case of test environment only, otherwise it gives error – Vipul Jain Apr 05 '17 at 06:20
I saw the same issue Vipul did. Errors when trying to use in real business logic. – wheeleruniverse Jan 30 '18 at 19:55

score 6 · Answer 2 · answered Dec 13 '13 at 17:05

    File file = new File("src/test/resources/validation.txt");
    DiskFileItem fileItem = new DiskFileItem("file", "text/plain", false, file.getName(), (int) file.length() , file.getParentFile());
    fileItem.getOutputStream();
    MultipartFile multipartFile = new CommonsMultipartFile(fileItem);

You need the

    fileItem.getOutputStream();

because it will throw NPE otherwise.

Converting File to MultiPartFile with spring

2 Answers2