Package com.vaadin.flow.server.streams

Class InputStreamDownloadHandler

java.lang.Object

com.vaadin.flow.server.streams.TransferProgressAwareHandler<DownloadEvent,InputStreamDownloadHandler>

com.vaadin.flow.server.streams.AbstractDownloadHandler<InputStreamDownloadHandler>

com.vaadin.flow.server.streams.InputStreamDownloadHandler

All Implemented Interfaces:

DownloadHandler, ElementRequestHandler, Serializable

public class InputStreamDownloadHandler
extends AbstractDownloadHandler<InputStreamDownloadHandler>

Download handler for serving an input stream for client download.

Since:

24.8

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
InputStreamDownloadHandler(InputStreamDownloadCallback callback)	Create an input stream download handler for given event -> response function.
InputStreamDownloadHandler(InputStreamDownloadCallback callback, String fileNameOverride)	Create an input stream download handler for given event -> response function.

Method Summary

Modifier and Type	Method	Description
String	getUrlPostfix()	Optional URL postfix allows appending an application-controlled string, e.g. the logical name of the target file, to the end of the otherwise random-looking download URL.
void	handleDownloadRequest(DownloadEvent downloadEvent)	Method that is called when the client wants to download from the url stored for this specific handler registration.

Methods inherited from class com.vaadin.flow.server.streams.AbstractDownloadHandler

getContentType, getTransferContext, inline, isInline

Methods inherited from class com.vaadin.flow.server.streams.TransferProgressAwareHandler

addTransferProgressListener, getListeners, notifyError, onProgress, onProgress, onProgress, onProgress, setTransferUI, uiAccess, whenComplete, whenComplete, whenStart, whenStart

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.flow.server.streams.DownloadHandler

allowDisabled, handleRequest

Methods inherited from interface com.vaadin.flow.server.streams.ElementRequestHandler

getDisabledUpdateMode, isAllowInert

Constructor Details

InputStreamDownloadHandler

public InputStreamDownloadHandler(InputStreamDownloadCallback callback)

Create an input stream download handler for given event -> response function.

Parameters:

callback - serializable function for handling download

InputStreamDownloadHandler

public InputStreamDownloadHandler(InputStreamDownloadCallback callback,
 String fileNameOverride)

Create an input stream download handler for given event -> response function.

The downloaded file fileNameOverride and download URL postfix will be set to fileNameOverride.

Parameters:

callback - serializable function for handling download

fileNameOverride - used as a downloaded file name as a download request URL postfix, e.g. /VAADIN/dynamic/resource/0/5298ee8b-9686-4a5a-ae1d-b38c62767d6a/my-file.txt

Method Details

handleDownloadRequest

public void handleDownloadRequest(DownloadEvent downloadEvent)
                           throws IOException

Description copied from interface: DownloadHandler

Method that is called when the client wants to download from the url stored for this specific handler registration.

Parameters:

downloadEvent - download event containing the necessary data for writing the response

Throws:

IOException - if an IO error occurred during download

getUrlPostfix

public String getUrlPostfix()

Description copied from interface: ElementRequestHandler

Optional URL postfix allows appending an application-controlled string, e.g. the logical name of the target file, to the end of the otherwise random-looking download URL. If defined, requests that would otherwise be routable are still rejected if the postfix is missing or invalid. Postfix changes the last segment in the resource url.

Returns:

String optional URL postfix, or null for "".