Package com.vaadin.flow.server.communication

Class TransferUtil

java.lang.Object

com.vaadin.flow.server.communication.TransferUtil

public final class TransferUtil
extends Object

Utility class with methods for handling transfer of upload and download requests.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_BUFFER_SIZE	Default buffer size for reading data from the input stream.

Constructor Summary

Constructors

Constructor	Description
TransferUtil()

Method Summary

Modifier and Type	Method	Description
static String	extractContentTypeFromXhrRequest(VaadinRequest request)	Extracts the content type from an XHR upload request.
static String	extractFilenameFromXhrRequest(VaadinRequest request)	Extracts the filename from an XHR upload request.
static void	handleUpload(UploadHandler handler, VaadinRequest request, VaadinResponse response, VaadinSession session, Element owner)	Handle upload request and call UploadHandler.handleUploadRequest(UploadEvent) correctly for xhr and multipart uploads.
static long	transfer(InputStream inputStream, OutputStream outputStream, TransferContext transferContext, Collection<TransferProgressListener> listeners)	Transfers data from the given input stream to the output stream while notifying the progress to the given listeners.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_BUFFER_SIZE

public static int DEFAULT_BUFFER_SIZE

Default buffer size for reading data from the input stream.

Follows the default buffer size of the Java InputStream.transferTo(OutputStream).

Constructor Details

TransferUtil

public TransferUtil()

Method Details

transfer

public static long transfer(InputStream inputStream,
 OutputStream outputStream,
 TransferContext transferContext,
 Collection<TransferProgressListener> listeners)
                     throws IOException

Transfers data from the given input stream to the output stream while notifying the progress to the given listeners.

Parameters:

inputStream - the input stream to read from

outputStream - the output stream to write to

transferContext - the transfer request containing metadata about the transfer

listeners - collection of listeners to notify about progress

Returns:

the number of bytes transferred

Throws:

IOException - if an I/O error occurs during the transfer

handleUpload

public static void handleUpload(UploadHandler handler,
 VaadinRequest request,
 VaadinResponse response,
 VaadinSession session,
 Element owner)

Handle upload request and call UploadHandler.handleUploadRequest(UploadEvent) correctly for xhr and multipart uploads.

Fires internal events for the owner upload component to indicate that the upload has started and completed.

For internal use only. May be renamed or removed in a future release.

Parameters:

handler - UploadHandler that should be called for this upload

request - The VaadinRequest for this upload

response - The VaadinResponse for this upload

session - Current VaadinSession

owner - The element that owns the request handler

extractFilenameFromXhrRequest

public static String extractFilenameFromXhrRequest(VaadinRequest request)

Extracts the filename from an XHR upload request.

The filename is extracted from the X-Filename header, which is set by vaadin-upload. The filename is encoded using JavaScript's encodeURIComponent and decoded on the server using UrlUtil.decodeURIComponent(String) (RFC 3986).

Parameters:

request - the request to extract the filename from

Returns:

the decoded filename, or "unknown" if not present

extractContentTypeFromXhrRequest

public static String extractContentTypeFromXhrRequest(VaadinRequest request)

Extracts the content type from an XHR upload request.

The content type is extracted from the Content-Type header.

Parameters:

request - the request to extract the content type from

Returns:

the content type, or "unknown" if not present