in commons-fileupload2-core/src/main/java/org/apache/commons/fileupload2/core/DiskFileItem.java [260:271]
private DiskFileItem(final String fieldName, final String contentType, final boolean isFormField, final String fileName, final int threshold,
final Path repository, final FileItemHeaders fileItemHeaders, final Charset defaultCharset) {
this.fieldName = fieldName;
this.contentType = contentType;
this.charsetDefault = defaultCharset;
this.isFormField = isFormField;
this.fileName = fileName;
this.fileItemHeaders = fileItemHeaders;
this.threshold = threshold;
this.repository = repository != null ? repository : PathUtils.getTempDirectory();
this.tempFile = this.repository.resolve(String.format("upload_%s_%s.tmp", UID, getUniqueId()));
}