org.springframework.core.io.buffer

Class DataBufferUtils

java.lang.Object

org.springframework.core.io.buffer.DataBufferUtils

public abstract class DataBufferUtils
extends 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
static interface	DataBufferUtils.Matcher Contract to find delimiter(s) against one or more data buffers that can be passed one at a time to the DataBufferUtils.Matcher.match(DataBuffer) method.

Constructor Summary

Constructors

Constructor and Description
DataBufferUtils()

Method Summary

Modifier and Type	Method and Description
static reactor.core.publisher.Mono<DataBuffer>	join(Publisher<? extends DataBuffer> dataBuffers) Return a new DataBuffer composed from joining together the given dataBuffers elements.
static reactor.core.publisher.Mono<DataBuffer>	join(Publisher<? extends DataBuffer> buffers, int maxByteCount) Variant of join(Publisher) that behaves the same way up until the specified max number of bytes to buffer.
static DataBufferUtils.Matcher	matcher(byte[]... delimiters) Return a DataBufferUtils.Matcher for the given delimiters.
static DataBufferUtils.Matcher	matcher(byte[] delimiter) Return a DataBufferUtils.Matcher for the given delimiter.
static reactor.core.publisher.Flux<DataBuffer>	read(Path path, DataBufferFactory bufferFactory, int bufferSize, OpenOption... options) Read bytes from the given file Path into a Flux of DataBuffers.
static reactor.core.publisher.Flux<DataBuffer>	read(Resource resource, DataBufferFactory bufferFactory, int bufferSize) Read the given Resource into a Flux of DataBuffers.
static reactor.core.publisher.Flux<DataBuffer>	read(Resource resource, long position, DataBufferFactory bufferFactory, int bufferSize) Read the given Resource into a Flux of DataBuffers starting at the given position.
static reactor.core.publisher.Flux<DataBuffer>	readAsynchronousFileChannel(Callable<AsynchronousFileChannel> channelSupplier, DataBufferFactory bufferFactory, int bufferSize) Obtain a AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers.
static reactor.core.publisher.Flux<DataBuffer>	readAsynchronousFileChannel(Callable<AsynchronousFileChannel> channelSupplier, long position, DataBufferFactory bufferFactory, int bufferSize) Obtain an AsynchronousFileChannel from the given supplier, and read it into a Flux of DataBuffers, starting at the given position.
static reactor.core.publisher.Flux<DataBuffer>	readByteChannel(Callable<ReadableByteChannel> channelSupplier, DataBufferFactory bufferFactory, int bufferSize) Obtain a ReadableByteChannel from the given supplier, and read it into a Flux of DataBuffers.
static reactor.core.publisher.Flux<DataBuffer>	readInputStream(Callable<InputStream> inputStreamSupplier, DataBufferFactory bufferFactory, int bufferSize) Obtain an 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 and has been allocated.
static 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, if it is a PooledDataBuffer.
static reactor.core.publisher.Flux<DataBuffer>	skipUntilByteCount(Publisher<? extends DataBuffer> 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 reactor.core.publisher.Flux<DataBuffer>	takeUntilByteCount(Publisher<? extends DataBuffer> 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 <T extends DataBuffer> T	touch(T dataBuffer, Object hint) Associate the given hint with the data buffer if it is a pooled buffer and supports leak tracking.
static reactor.core.publisher.Flux<DataBuffer>	write(Publisher<? extends DataBuffer> source, AsynchronousFileChannel channel, long position) Write the given stream of DataBuffers to the given AsynchronousFileChannel.
static reactor.core.publisher.Flux<DataBuffer>	write(Publisher<DataBuffer> source, AsynchronousFileChannel channel) Write the given stream of DataBuffers to the given AsynchronousFileChannel.
static reactor.core.publisher.Flux<DataBuffer>	write(Publisher<DataBuffer> source, OutputStream outputStream) Write the given stream of DataBuffers to the given OutputStream.
static reactor.core.publisher.Mono<Void>	write(Publisher<DataBuffer> source, Path destination, OpenOption... options) Write the given stream of DataBuffers to the given file Path.
static reactor.core.publisher.Flux<DataBuffer>	write(Publisher<DataBuffer> source, 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

Constructor Detail

DataBufferUtils

public DataBufferUtils()

Method Detail

readInputStream

public static reactor.core.publisher.Flux<DataBuffer> readInputStream(Callable<InputStream> inputStreamSupplier,
                                                                      DataBufferFactory bufferFactory,
                                                                      int bufferSize)

Obtain an 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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> readByteChannel(Callable<ReadableByteChannel> channelSupplier,
                                                                      DataBufferFactory bufferFactory,
                                                                      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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> readAsynchronousFileChannel(Callable<AsynchronousFileChannel> channelSupplier,
                                                                                  DataBufferFactory bufferFactory,
                                                                                  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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> readAsynchronousFileChannel(Callable<AsynchronousFileChannel> channelSupplier,
                                                                                  long position,
                                                                                  DataBufferFactory bufferFactory,
                                                                                  int bufferSize)

Obtain an 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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> read(Path path,
                                                           DataBufferFactory bufferFactory,
                                                           int bufferSize,
                                                           OpenOption... options)

Read bytes from the given file Path into a Flux of DataBuffers. The method ensures that the file is closed when the flux is terminated.

Parameters:

path - the path to read bytes from

bufferFactory - 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

Since:

5.2

read

public static reactor.core.publisher.Flux<DataBuffer> read(Resource resource,
                                                           DataBufferFactory bufferFactory,
                                                           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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> read(Resource resource,
                                                           long position,
                                                           DataBufferFactory bufferFactory,
                                                           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

bufferFactory - 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 reactor.core.publisher.Flux<DataBuffer> write(Publisher<DataBuffer> source,
                                                            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 reactor.core.publisher.Flux<DataBuffer> write(Publisher<DataBuffer> source,
                                                            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 reactor.core.publisher.Flux<DataBuffer> write(Publisher<DataBuffer> source,
                                                            AsynchronousFileChannel channel)

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

Since:

5.0.10

write

public static reactor.core.publisher.Flux<DataBuffer> write(Publisher<? extends DataBuffer> source,
                                                            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

position - the file position where writing is to begin; must be non-negative

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 reactor.core.publisher.Mono<Void> write(Publisher<DataBuffer> source,
                                                      Path destination,
                                                      OpenOption... options)

Write the given stream of DataBuffers to the given file Path. The optional options parameter specifies how the file is created or opened (defaults to CREATE, TRUNCATE_EXISTING, and WRITE).

Parameters:

source - the stream of data buffers to be written

destination - the path to the file

options - the options specifying how the file is opened

Returns:

a Mono that indicates completion or error

Since:

5.2

takeUntilByteCount

public static reactor.core.publisher.Flux<DataBuffer> takeUntilByteCount(Publisher<? extends DataBuffer> 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 reactor.core.publisher.Flux<DataBuffer> skipUntilByteCount(Publisher<? extends DataBuffer> 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, if it is a PooledDataBuffer.

Parameters:

dataBuffer - the data buffer to retain

Returns:

the retained buffer

touch

public static <T extends DataBuffer> T touch(T dataBuffer,
                                             Object hint)

Associate the given hint with the data buffer if it is a pooled buffer and supports leak tracking.

Parameters:

dataBuffer - the data buffer to attach the hint to

hint - the hint to attach

Returns:

the input buffer

Since:

5.3.2

release

public static boolean release(@Nullable
                              DataBuffer dataBuffer)

Release the given data buffer, if it is a PooledDataBuffer and has been allocated.

Parameters:

dataBuffer - the data buffer to release

Returns:

true if the buffer was released; false otherwise.

releaseConsumer

public static Consumer<DataBuffer> releaseConsumer()

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

join

public static reactor.core.publisher.Mono<DataBuffer> join(Publisher<? extends DataBuffer> dataBuffers)

Return a new DataBuffer composed from joining together the given dataBuffers elements. Depending on the DataBuffer type, the returned buffer may be a single buffer containing all data of the provided buffers, or it may be a zero-copy, composite with references to the given buffers.

If dataBuffers produces an error or if there is a cancel signal, then all accumulated buffers will be released.

Note that the given data buffers do not have to be released. They will be released as part of the returned composite.

Parameters:

dataBuffers - the data buffers that are to be composed

Returns:

a buffer that is composed from the dataBuffers argument

Since:

5.0.3

join

public static reactor.core.publisher.Mono<DataBuffer> join(Publisher<? extends DataBuffer> buffers,
                                                           int maxByteCount)

Variant of join(Publisher) that behaves the same way up until the specified max number of bytes to buffer. Once the limit is exceeded, DataBufferLimitException is raised.

Parameters:

buffers - the data buffers that are to be composed

maxByteCount - the max number of bytes to buffer, or -1 for unlimited

Returns:

a buffer with the aggregated content, possibly an empty Mono if the max number of bytes to buffer is exceeded.

Throws:

DataBufferLimitException - if maxByteCount is exceeded

Since:

5.1.11

matcher

public static DataBufferUtils.Matcher matcher(byte[] delimiter)

Return a DataBufferUtils.Matcher for the given delimiter. The matcher can be used to find the delimiters in a stream of data buffers.

Parameters:

delimiter - the delimiter bytes to find

Returns:

the matcher

Since:

5.2

matcher

public static DataBufferUtils.Matcher matcher(byte[]... delimiters)

Return a DataBufferUtils.Matcher for the given delimiters. The matcher can be used to find the delimiters in a stream of data buffers.

Parameters:

delimiters - the delimiters bytes to find

Returns:

the matcher

Since:

5.2