com.azure.core.util

Class FluxUtil

java.lang.Object

com.azure.core.util.FluxUtil

public final class FluxUtil
extends Object

Utility type exposing methods to deal with Flux.

Method Summary

Modifier and Type	Method and Description
static byte[]	byteBufferToArray(ByteBuffer byteBuffer) Gets the content of the provided ByteBuffer as a byte array.
static Mono<byte[]>	collectBytesFromNetworkResponse(Flux<ByteBuffer> stream, HttpHeaders headers) Collects ByteBuffers returned in a network response into a byte array.
static Mono<byte[]>	collectBytesInByteBufferStream(Flux<ByteBuffer> stream) Collects ByteBuffers emitted by a Flux into a byte array.
static Mono<byte[]>	collectBytesInByteBufferStream(Flux<ByteBuffer> stream, int sizeHint) Collects ByteBuffers emitted by a Flux into a byte array.
static <T> Flux<T>	fluxContext(Function<Context,Flux<T>> serviceCall) This method converts the incoming deferContextual from Reactor Context to Azure Context and calls the given lambda function with this context and returns a collection of type T
static <T> Flux<T>	fluxError(ClientLogger logger, RuntimeException ex) Propagates a RuntimeException through the error channel of Flux.
static boolean	isFluxByteBuffer(Type entityType) Checks if a type is Flux<ByteBuffer>.
static <T> Mono<T>	monoError(ClientLogger logger, RuntimeException ex) Propagates a RuntimeException through the error channel of Mono.
static <T> PagedFlux<T>	pagedFluxError(ClientLogger logger, RuntimeException ex) Propagates a RuntimeException through the error channel of PagedFlux.
static Flux<ByteBuffer>	readFile(AsynchronousFileChannel fileChannel) Creates a Flux from an AsynchronousFileChannel which reads the entire file.
static Flux<ByteBuffer>	readFile(AsynchronousFileChannel fileChannel, int chunkSize, long offset, long length) Creates a Flux from an AsynchronousFileChannel which reads part of a file into chunks of the given size.
static Flux<ByteBuffer>	readFile(AsynchronousFileChannel fileChannel, long offset, long length) Creates a Flux from an AsynchronousFileChannel which reads part of a file.
static Flux<ByteBuffer>	toFluxByteBuffer(InputStream inputStream) Converts an InputStream into a Flux of ByteBuffer using a chunk size of 4096.
static Flux<ByteBuffer>	toFluxByteBuffer(InputStream inputStream, int chunkSize) Converts an InputStream into a Flux of ByteBuffer.
static <T> Mono<T>	toMono(Response<T> response) Converts the incoming content to Mono.
static Context	toReactorContext(Context context) Converts an Azure context to Reactor context.
static <T> Mono<T>	withContext(Function<Context,Mono<T>> serviceCall) This method converts the incoming deferContextual from Reactor Context to Azure Context and calls the given lambda function with this context and returns a single entity of type T
static <T> Mono<T>	withContext(Function<Context,Mono<T>> serviceCall, Map<String,String> contextAttributes) This method converts the incoming deferContextual from Reactor Context to Azure Context, adds the specified context attributes and calls the given lambda function with this context and returns a single entity of type T
static Mono<Void>	writeFile(Flux<ByteBuffer> content, AsynchronousFileChannel outFile) Writes the bytes emitted by a Flux to an AsynchronousFileChannel.
static Mono<Void>	writeFile(Flux<ByteBuffer> content, AsynchronousFileChannel outFile, long position) Writes the bytes emitted by a Flux to an AsynchronousFileChannel starting at the given position in the file.

Methods inherited from class java.lang.Object

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

Method Detail

isFluxByteBuffer

public static boolean isFluxByteBuffer(Type entityType)

Checks if a type is Flux<ByteBuffer>.

Parameters:

entityType - the type to check

Returns:

whether the type represents a Flux that emits ByteBuffer

collectBytesInByteBufferStream

public static Mono<byte[]> collectBytesInByteBufferStream(Flux<ByteBuffer> stream)

Collects ByteBuffers emitted by a Flux into a byte array.

Parameters:

stream - A stream which emits ByteBuffer instances.

Returns:

A Mono which emits the concatenation of all the ByteBuffer instances given by the source Flux.

Throws:

IllegalStateException - If the combined size of the emitted ByteBuffers is greater than Integer.MAX_VALUE.

collectBytesInByteBufferStream

public static Mono<byte[]> collectBytesInByteBufferStream(Flux<ByteBuffer> stream,
                                                          int sizeHint)

Collects ByteBuffers emitted by a Flux into a byte array.

Unlike FluxUtil.collectBytesInByteBufferStream(Flux), this method accepts a second parameter sizeHint. This size hint allows for optimizations when creating the initial buffer to reduce the number of times it needs to be resized while concatenating emitted ByteBuffers.

Parameters:

stream - A stream which emits ByteBuffer instances.

sizeHint - A hint about the expected stream size.

Returns:

A Mono which emits the concatenation of all the ByteBuffer instances given by the source Flux.

Throws:

IllegalArgumentException - If sizeHint is equal to or less than 0.

IllegalStateException - If the combined size of the emitted ByteBuffers is greater than Integer.MAX_VALUE.

collectBytesFromNetworkResponse

public static Mono<byte[]> collectBytesFromNetworkResponse(Flux<ByteBuffer> stream,
                                                           HttpHeaders headers)

Collects ByteBuffers returned in a network response into a byte array.

The headers are inspected for containing an Content-Length which determines if a size hinted collection, FluxUtil.collectBytesInByteBufferStream(Flux, int), or default collection, FluxUtil.collectBytesInByteBufferStream(Flux), will be used.

Parameters:

stream - A network response ByteBuffer stream.

headers - The HTTP headers of the response.

Returns:

A Mono which emits the collected network response ByteBuffers.

Throws:

NullPointerException - If headers is null.

IllegalStateException - If the size of the network response is greater than Integer.MAX_VALUE.

byteBufferToArray

public static byte[] byteBufferToArray(ByteBuffer byteBuffer)

Gets the content of the provided ByteBuffer as a byte array. This method will create a new byte array even if the ByteBuffer can have optionally backing array.

Parameters:

byteBuffer - the byte buffer

Returns:

the byte array

toFluxByteBuffer

public static Flux<ByteBuffer> toFluxByteBuffer(InputStream inputStream)

Converts an InputStream into a Flux of ByteBuffer using a chunk size of 4096.

Given that InputStream is not guaranteed to be replayable the returned Flux should be considered non-replayable as well.

If the passed InputStream is null Flux.empty() will be returned.

Parameters:

inputStream - The InputStream to convert into a Flux.

Returns:

A Flux of ByteBuffers that contains the contents of the stream.

toFluxByteBuffer

public static Flux<ByteBuffer> toFluxByteBuffer(InputStream inputStream,
                                                int chunkSize)

Converts an InputStream into a Flux of ByteBuffer.

Given that InputStream is not guaranteed to be replayable the returned Flux should be considered non-replayable as well.

If the passed InputStream is null Flux.empty() will be returned.

Parameters:

inputStream - The InputStream to convert into a Flux.

chunkSize - The requested size for each ByteBuffer.

Returns:

A Flux of ByteBuffers that contains the contents of the stream.

Throws:

IllegalArgumentException - If chunkSize is less than or equal to 0.

withContext

public static <T> Mono<T> withContext(Function<Context,Mono<T>> serviceCall)

This method converts the incoming deferContextual from Reactor Context to Azure Context and calls the given lambda function with this context and returns a single entity of type T

If the reactor context is empty, Context.NONE will be used to call the lambda function

Code samples

 String prefix = "Hello, ";
 Mono<String> response = FluxUtil
     .withContext(context -> serviceCallReturnsSingle(prefix, context));
 

Type Parameters:

T - The type of response returned from the service call

Parameters:

serviceCall - The lambda function that makes the service call into which azure context will be passed

Returns:

The response from service call

withContext

public static <T> Mono<T> withContext(Function<Context,Mono<T>> serviceCall,
                                      Map<String,String> contextAttributes)

This method converts the incoming deferContextual from Reactor Context to Azure Context, adds the specified context attributes and calls the given lambda function with this context and returns a single entity of type T

If the reactor context is empty, Context.NONE will be used to call the lambda function

Type Parameters:

T - The type of response returned from the service call

Parameters:

serviceCall - serviceCall The lambda function that makes the service call into which azure context will be passed

contextAttributes - The map of attributes sent by the calling method to be set on Context.

Returns:

The response from service call

toMono

public static <T> Mono<T> toMono(Response<T> response)

Converts the incoming content to Mono.

Type Parameters:

T - The type of the Response, which will be returned in the Mono.

Parameters:

response - whose value is to be converted

Returns:

The converted Mono

monoError

public static <T> Mono<T> monoError(ClientLogger logger,
                                    RuntimeException ex)

Propagates a RuntimeException through the error channel of Mono.

Type Parameters:

T - The return type.

Parameters:

logger - The ClientLogger to log the exception.

ex - The RuntimeException.

Returns:

A Mono that terminates with error wrapping the RuntimeException.

fluxError

public static <T> Flux<T> fluxError(ClientLogger logger,
                                    RuntimeException ex)

Propagates a RuntimeException through the error channel of Flux.

Type Parameters:

T - The return type.

Parameters:

logger - The ClientLogger to log the exception.

ex - The RuntimeException.

Returns:

A Flux that terminates with error wrapping the RuntimeException.

pagedFluxError

public static <T> PagedFlux<T> pagedFluxError(ClientLogger logger,
                                              RuntimeException ex)

Propagates a RuntimeException through the error channel of PagedFlux.

Type Parameters:

T - The return type.

Parameters:

logger - The ClientLogger to log the exception.

ex - The RuntimeException.

Returns:

A PagedFlux that terminates with error wrapping the RuntimeException.

fluxContext

public static <T> Flux<T> fluxContext(Function<Context,Flux<T>> serviceCall)

This method converts the incoming deferContextual from Reactor Context to Azure Context and calls the given lambda function with this context and returns a collection of type T

If the reactor context is empty, Context.NONE will be used to call the lambda function

Code samples

 String prefix = "Hello, ";
 Flux<String> response = FluxUtil
     .fluxContext(context -> serviceCallReturnsCollection(prefix, context));
 

Type Parameters:

T - The type of response returned from the service call

Parameters:

serviceCall - The lambda function that makes the service call into which the context will be passed

Returns:

The response from service call

toReactorContext

public static Context toReactorContext(Context context)

Converts an Azure context to Reactor context. If the Azure context is null or empty, Context.empty() will be returned.

Parameters:

context - The Azure context.

Returns:

The Reactor context.

writeFile

public static Mono<Void> writeFile(Flux<ByteBuffer> content,
                                   AsynchronousFileChannel outFile)

Writes the bytes emitted by a Flux to an AsynchronousFileChannel.

Parameters:

content - the Flux content

outFile - the file channel

Returns:

a Mono which performs the write operation when subscribed

writeFile

public static Mono<Void> writeFile(Flux<ByteBuffer> content,
                                   AsynchronousFileChannel outFile,
                                   long position)

Writes the bytes emitted by a Flux to an AsynchronousFileChannel starting at the given position in the file.

Parameters:

content - the Flux content

outFile - the file channel

position - the position in the file to begin writing

Returns:

a Mono which performs the write operation when subscribed

readFile

public static Flux<ByteBuffer> readFile(AsynchronousFileChannel fileChannel,
                                        int chunkSize,
                                        long offset,
                                        long length)

Creates a Flux from an AsynchronousFileChannel which reads part of a file into chunks of the given size.

Parameters:

fileChannel - The file channel.

chunkSize - the size of file chunks to read.

offset - The offset in the file to begin reading.

length - The number of bytes to read from the file.

Returns:

the Flux.

readFile

public static Flux<ByteBuffer> readFile(AsynchronousFileChannel fileChannel,
                                        long offset,
                                        long length)

Creates a Flux from an AsynchronousFileChannel which reads part of a file.

Parameters:

fileChannel - The file channel.

offset - The offset in the file to begin reading.

length - The number of bytes to read from the file.

Returns:

the Flux.

readFile

public static Flux<ByteBuffer> readFile(AsynchronousFileChannel fileChannel)

Creates a Flux from an AsynchronousFileChannel which reads the entire file.

Parameters:

fileChannel - The file channel.

Returns:

The AsyncInputStream.