org.springframework.core.io.buffer

Class DataBufferUtils

java.lang.Object

org.springframework.core.io.buffer.DataBufferUtils

public abstract class DataBufferUtils
extends java.lang.Object

Utility class for working with DataBuffers.

Since:

5.0

Author:

Arjen Poutsma, Brian Clozel

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	DataBufferUtils.AsynchronousFileChannelReadCompletionHandler
private static class	DataBufferUtils.AsynchronousFileChannelWriteCompletionHandler
private static class	DataBufferUtils.ReadableByteChannelGenerator

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.function.Consumer<DataBuffer>	RELEASE_CONSUMER

Constructor Summary

Constructors

Constructor and Description
DataBufferUtils()

Method Summary

Modifier and Type	Method and Description
private static void	closeChannel(java.nio.channels.Channel channel)
static <any>	join(<any> dataBuffers) Return a new DataBuffer composed of the dataBuffers elements joined together.
static <any>	read(java.nio.channels.AsynchronousFileChannel channel, DataBufferFactory dataBufferFactory, int bufferSize) Deprecated. as of Spring 5.0.3, in favor of readAsynchronousFileChannel(Callable, DataBufferFactory, int), to be removed in Spring 5.1
static <any>	read(java.nio.channels.AsynchronousFileChannel channel, long position, DataBufferFactory dataBufferFactory, int bufferSize) Deprecated. as of Spring 5.0.3, in favor of readAsynchronousFileChannel(Callable, long, DataBufferFactory, int), to be removed in Spring 5.1
static <any>	read(java.io.InputStream inputStream, DataBufferFactory dataBufferFactory, int bufferSize) Deprecated. as of Spring 5.0.3, in favor of readInputStream(Callable, DataBufferFactory, int), to be removed in Spring 5.1
static <any>	read(java.nio.channels.ReadableByteChannel channel, DataBufferFactory dataBufferFactory, int bufferSize) Deprecated. as of Spring 5.0.3, in favor of readByteChannel(Callable, DataBufferFactory, int), to be removed in Spring 5.1
static <any>	read(Resource resource, DataBufferFactory dataBufferFactory, int bufferSize) Read the given Resource into a Flux of DataBuffers.
static <any>	read(Resource resource, long position, DataBufferFactory dataBufferFactory, int bufferSize) Read the given Resource into a Flux of DataBuffers starting at the given position.
static <any>	readAsynchronousFileChannel(java.util.concurrent.Callable<java.nio.channels.AsynchronousFileChannel> channelSupplier, DataBufferFactory dataBufferFactory, int bufferSize) Obtain a AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers.
static <any>	readAsynchronousFileChannel(java.util.concurrent.Callable<java.nio.channels.AsynchronousFileChannel> channelSupplier, long position, DataBufferFactory dataBufferFactory, int bufferSize) Obtain a AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers, starting at the given position.
static <any>	readByteChannel(java.util.concurrent.Callable<java.nio.channels.ReadableByteChannel> channelSupplier, DataBufferFactory dataBufferFactory, int bufferSize) Obtain a ReadableByteChannel from the given supplier, and read it into a Flux of DataBuffers.
static <any>	readInputStream(java.util.concurrent.Callable<java.io.InputStream> inputStreamSupplier, DataBufferFactory dataBufferFactory, int bufferSize) Obtain a InputStream from the given supplier, and read it into a Flux of DataBuffers.
static boolean	release(DataBuffer dataBuffer) Release the given data buffer, if it is a PooledDataBuffer.
static java.util.function.Consumer<DataBuffer>	releaseConsumer() Return a consumer that calls release(DataBuffer) on all passed data buffers.
static <T extends DataBuffer> T	retain(T dataBuffer) Retain the given data buffer, it it is a PooledDataBuffer.
static <any>	skipUntilByteCount(<any> publisher, long maxByteCount) Skip buffers from the given Publisher until the total byte count reaches the given maximum byte count, or until the publisher is complete.
static <any>	takeUntilByteCount(<any> publisher, long maxByteCount) Relay buffers from the given Publisher until the total byte count reaches the given maximum byte count, or until the publisher is complete.
static <any>	write(<any> source, java.nio.channels.AsynchronousFileChannel channel, long position) Write the given stream of DataBuffers to the given AsynchronousFileChannel.
static <any>	write(<any> source, java.io.OutputStream outputStream) Write the given stream of DataBuffers to the given OutputStream.
static <any>	write(<any> source, java.nio.channels.WritableByteChannel channel) Write the given stream of DataBuffers to the given WritableByteChannel.

Methods inherited from class java.lang.Object

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

Field Detail

RELEASE_CONSUMER

private static final java.util.function.Consumer<DataBuffer> RELEASE_CONSUMER

Constructor Detail

DataBufferUtils

public DataBufferUtils()

Method Detail

read

@Deprecated
public static <any> read(java.io.InputStream inputStream,
                                     DataBufferFactory dataBufferFactory,
                                     int bufferSize)

Deprecated. as of Spring 5.0.3, in favor of readInputStream(Callable, DataBufferFactory, int), to be removed in Spring 5.1

Read the given InputStream into a read-once Flux of DataBuffers. Closes the input stream when the flux is terminated.

The resulting Flux can only be subscribed to once. See readInputStream(Callable, DataBufferFactory, int) for a variant that supports multiple subscriptions.

Parameters:

inputStream - the input stream to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

readInputStream

public static <any> readInputStream(java.util.concurrent.Callable<java.io.InputStream> inputStreamSupplier,
                                    DataBufferFactory dataBufferFactory,
                                    int bufferSize)

Obtain a InputStream from the given supplier, and read it into a Flux of DataBuffers. Closes the input stream when the flux is terminated.

Parameters:

inputStreamSupplier - the supplier for the input stream to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

read

@Deprecated
public static <any> read(java.nio.channels.ReadableByteChannel channel,
                                     DataBufferFactory dataBufferFactory,
                                     int bufferSize)

Deprecated. as of Spring 5.0.3, in favor of readByteChannel(Callable, DataBufferFactory, int), to be removed in Spring 5.1

Read the given ReadableByteChannel into a read-once Flux of DataBuffers. Closes the channel when the flux is terminated.

The resulting Flux can only be subscribed to once. See readByteChannel(Callable, DataBufferFactory, int) for a variant that supports multiple subscriptions.

Parameters:

channel - the channel to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

readByteChannel

public static <any> readByteChannel(java.util.concurrent.Callable<java.nio.channels.ReadableByteChannel> channelSupplier,
                                    DataBufferFactory dataBufferFactory,
                                    int bufferSize)

Obtain a ReadableByteChannel from the given supplier, and read it into a Flux of DataBuffers. Closes the channel when the flux is terminated.

Parameters:

channelSupplier - the supplier for the channel to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

read

@Deprecated
public static <any> read(java.nio.channels.AsynchronousFileChannel channel,
                                     DataBufferFactory dataBufferFactory,
                                     int bufferSize)

Deprecated. as of Spring 5.0.3, in favor of readAsynchronousFileChannel(Callable, DataBufferFactory, int), to be removed in Spring 5.1

Read the given AsynchronousFileChannel into a read-once Flux of DataBuffers. Closes the channel when the flux is terminated.

The resulting Flux can only be subscribed to once. See readAsynchronousFileChannel(Callable, DataBufferFactory, int) for a variant that supports multiple subscriptions.

Parameters:

channel - the channel to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

read

@Deprecated
public static <any> read(java.nio.channels.AsynchronousFileChannel channel,
                                     long position,
                                     DataBufferFactory dataBufferFactory,
                                     int bufferSize)

Deprecated. as of Spring 5.0.3, in favor of readAsynchronousFileChannel(Callable, long, DataBufferFactory, int), to be removed in Spring 5.1

Read the given AsynchronousFileChannel into a read-once Flux of DataBuffers, starting at the given position. Closes the channel when the flux is terminated.

The resulting Flux can only be subscribed to once. See readAsynchronousFileChannel(Callable, long, DataBufferFactory, int) for a variant that supports multiple subscriptions.

Parameters:

channel - the channel to read from

position - the position to start reading from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

readAsynchronousFileChannel

public static <any> readAsynchronousFileChannel(java.util.concurrent.Callable<java.nio.channels.AsynchronousFileChannel> channelSupplier,
                                                DataBufferFactory dataBufferFactory,
                                                int bufferSize)

Obtain a AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers. Closes the channel when the flux is terminated.

Parameters:

channelSupplier - the supplier for the channel to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

readAsynchronousFileChannel

public static <any> readAsynchronousFileChannel(java.util.concurrent.Callable<java.nio.channels.AsynchronousFileChannel> channelSupplier,
                                                long position,
                                                DataBufferFactory dataBufferFactory,
                                                int bufferSize)

Obtain a AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers, starting at the given position. Closes the channel when the flux is terminated.

Parameters:

channelSupplier - the supplier for the channel to read from

position - the position to start reading from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

read

public static <any> read(Resource resource,
                         DataBufferFactory dataBufferFactory,
                         int bufferSize)

Read the given Resource into a Flux of DataBuffers.

If the resource is a file, it is read into an AsynchronousFileChannel and turned to Flux via readAsynchronousFileChannel(Callable, DataBufferFactory, int) or else fall back to readByteChannel(Callable, DataBufferFactory, int). Closes the channel when the flux is terminated.

Parameters:

resource - the resource to read from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

read

public static <any> read(Resource resource,
                         long position,
                         DataBufferFactory dataBufferFactory,
                         int bufferSize)

Read the given Resource into a Flux of DataBuffers starting at the given position.

If the resource is a file, it is read into an AsynchronousFileChannel and turned to Flux via readAsynchronousFileChannel(Callable, DataBufferFactory, int) or else fall back on readByteChannel(Callable, DataBufferFactory, int). Closes the channel when the flux is terminated.

Parameters:

resource - the resource to read from

position - the position to start reading from

dataBufferFactory - the factory to create data buffers with

bufferSize - the maximum size of the data buffers

Returns:

a flux of data buffers read from the given channel

write

public static <any> write(<any> source,
                          java.io.OutputStream outputStream)

Write the given stream of DataBuffers to the given OutputStream. Does not close the output stream when the flux is terminated, and does not release the data buffers in the source. If releasing is required, then subscribe to the returned Flux with a releaseConsumer().

Note that the writing process does not start until the returned Flux is subscribed to.

Parameters:

source - the stream of data buffers to be written

outputStream - the output stream to write to

Returns:

a flux containing the same buffers as in source, that starts the writing process when subscribed to, and that publishes any writing errors and the completion signal

write

public static <any> write(<any> source,
                          java.nio.channels.WritableByteChannel channel)

Write the given stream of DataBuffers to the given WritableByteChannel. Does not close the channel when the flux is terminated, and does not release the data buffers in the source. If releasing is required, then subscribe to the returned Flux with a releaseConsumer().

Note that the writing process does not start until the returned Flux is subscribed to.

Parameters:

source - the stream of data buffers to be written

channel - the channel to write to

Returns:

a flux containing the same buffers as in source, that starts the writing process when subscribed to, and that publishes any writing errors and the completion signal

write

public static <any> write(<any> source,
                          java.nio.channels.AsynchronousFileChannel channel,
                          long position)

Write the given stream of DataBuffers to the given AsynchronousFileChannel. Does not close the channel when the flux is terminated, and does not release the data buffers in the source. If releasing is required, then subscribe to the returned Flux with a releaseConsumer().

Note that the writing process does not start until the returned Flux is subscribed to.

Parameters:

source - the stream of data buffers to be written

channel - the channel to write to

Returns:

a flux containing the same buffers as in source, that starts the writing process when subscribed to, and that publishes any writing errors and the completion signal

closeChannel

private static void closeChannel(@Nullable
                                 java.nio.channels.Channel channel)

takeUntilByteCount

public static <any> takeUntilByteCount(<any> publisher,
                                       long maxByteCount)

Relay buffers from the given Publisher until the total byte count reaches the given maximum byte count, or until the publisher is complete.

Parameters:

publisher - the publisher to filter

maxByteCount - the maximum byte count

Returns:

a flux whose maximum byte count is maxByteCount

skipUntilByteCount

public static <any> skipUntilByteCount(<any> publisher,
                                       long maxByteCount)

Skip buffers from the given Publisher until the total byte count reaches the given maximum byte count, or until the publisher is complete.

Parameters:

publisher - the publisher to filter

maxByteCount - the maximum byte count

Returns:

a flux with the remaining part of the given publisher

retain

public static <T extends DataBuffer> T retain(T dataBuffer)

Retain the given data buffer, it it is a PooledDataBuffer.

Parameters:

dataBuffer - the data buffer to retain

Returns:

the retained buffer

release

public static boolean release(@Nullable
                              DataBuffer dataBuffer)

Release the given data buffer, if it is a PooledDataBuffer.

Parameters:

dataBuffer - the data buffer to release

Returns:

true if the buffer was released; false otherwise.

releaseConsumer

public static java.util.function.Consumer<DataBuffer> releaseConsumer()

Return a consumer that calls release(DataBuffer) on all passed data buffers.

join

public static <any> join(<any> dataBuffers)

Return a new DataBuffer composed of the dataBuffers elements joined together. Depending on the DataBuffer implementation, the returned buffer may be a single buffer containing all data of the provided buffers, or it may be a true composite that contains references to the buffers.

Parameters:

dataBuffers - the data buffers that are to be composed

Returns:

a buffer that is composed from the dataBuffers argument

Since:

5.0.3