jodd-core/src/main/java/jodd/io/upload/MultipartRequestInputStream.java
public FileUploadHeader readDataHeader(final String encoding) throws IOException {
		String dataHeader = readDataHeaderString(encoding);
		if (dataHeader != null) {
			lastHeader = new FileUploadHeader(dataHeader);
		} else {
			lastHeader = null;
		}
		return lastHeader;
	}
public FileUploadHeader readDataHeader(final String encoding) throws IOException {
		String dataHeader = readDataHeaderString(encoding);
		if (dataHeader != null) {
			lastHeader = new FileUploadHeader(dataHeader);
		} else {
			lastHeader = null;
		}
		return lastHeader;
	}
Reads data header from the input stream. When there is no more
headers (i.e. end of stream reached), returns <code>null</code>