java.lang.NullPointerException while creating DiskFileItem

Question

I am trying to write a unit test for handling a file upload controller using Spring 3. Now if I send the image over to my service method through the controller everything wo

Answer 1

I ran into the same problem. The issue is that DiskFileItem.getSize() is temporally coupled with DiskFileItem.getOutputStream() in that an internal field is initialized in getOutputStream and used in getSize.

The solution is to do

final File TEST_FILE = new File("src/test/resources/test.jpg");
final DiskFileItem diskFileItem = new DiskFileItem("file", "image/jpeg", true, TEST_FILE.getName(), 100000000, TEST_FILE.getParentFile());
diskFileItem.getOutputStream();

before passing diskFileItem to the constructor of CommonsMultipartFile.