UploadDataProvider

public abstract class UploadDataProvider extends Object
implements Closeable

Abstract class allowing the embedder to provide an upload body to UrlRequest. It supports both non-chunked (size known in advanced) and chunked (size not known in advance) uploads. Be aware that not all servers support chunked uploads.

An upload is either always chunked, across multiple uploads if the data ends up being sent more than once, or never chunked.

Public Constructor Summary

UploadDataProvider()

Public Method Summary

void	close() Called when this UploadDataProvider is no longer needed by a request, so that resources (like a file) can be explicitly released.
abstract long	getLength() If this is a non-chunked upload, returns the length of the upload.
abstract void	read(UploadDataSink uploadDataSink, ByteBuffer byteBuffer) Reads upload data into `byteBuffer`.
abstract void	rewind(UploadDataSink uploadDataSink) Rewinds upload data.

Inherited Method Summary

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

From interface java.io.Closeable

abstract void

close()

From interface java.lang.AutoCloseable

abstract void

close()

Public Constructors

public UploadDataProvider ()

Public Methods

public void close ()

Called when this UploadDataProvider is no longer needed by a request, so that resources (like a file) can be explicitly released.

Throws

IOException	if any IOException occurred during the process. This will cause the request to fail if it is not yet complete; otherwise it will be logged.

public abstract long getLength ()

If this is a non-chunked upload, returns the length of the upload. Must always return -1 if this is a chunked upload.

Returns

the length of the upload for non-chunked uploads, -1 otherwise.

Throws

IOException	if any IOException occurred during the process.

public abstract void read (UploadDataSink uploadDataSink, ByteBuffer byteBuffer)

Reads upload data into byteBuffer. Upon completion, the buffer's position is updated to the end of the bytes that were read. The buffer's limit is not changed. Each call of this method must be followed be a single call, either synchronous or asynchronous, to uploadDataSink: UploadDataSink.onReadSucceeded(boolean) on success or UploadDataSink.onReadError(Exception) on failure. Neither read nor rewind will be called until one of those methods or the other is called. Even if the associated UrlRequest is canceled, one or the other must still be called before resources can be safely freed. Throwing an exception will also result in resources being freed and the request being errored out.

Parameters

uploadDataSink	The object to notify when the read has completed, successfully or otherwise.
byteBuffer	The buffer to copy the read bytes into. Do not change byteBuffer's limit.

Throws

IOException	if any IOException occurred during the process. `UrlRequest.Callback.onFailed(UrlRequest, UrlResponseInfo, CronetException)` will be called with the thrown exception set as the cause of the `CallbackException`.

public abstract void rewind (UploadDataSink uploadDataSink)

Rewinds upload data. Each call must be followed be a single call, either synchronous or asynchronous, to uploadDataSink: UploadDataSink.onRewindSucceeded() on success or UploadDataSink.onRewindError(Exception) on failure. Neither read nor rewind will be called until one of those methods or the other is called. Even if the associated UrlRequest is canceled, one or the other must still be called before resources can be safely freed. Throwing an exception will also result in resources being freed and the request being errored out.

If rewinding is not supported, this should call UploadDataSink.onRewindError(Exception). Note that rewinding is required to follow redirects that preserve the upload body, and for retrying when the server times out stale sockets.

Parameters

uploadDataSink	The object to notify when the rewind operation has completed, successfully or otherwise.

Throws

IOException	if any IOException occurred during the process. `UrlRequest.Callback.onFailed(UrlRequest, UrlResponseInfo, CronetException)` will be called with the thrown exception set as the cause of the `CallbackException`.