Package com.azure.core.util

Class FluxUtil

  • public final class FluxUtil
extends Object
    Utility type exposing methods to deal with Flux.

    • 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 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.

      • 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

      • createRetriableDownloadFlux

        public static Flux<ByteBuffer> createRetriableDownloadFlux​(Supplier<Flux<ByteBuffer>> downloadSupplier,
                                                           BiFunction<Throwable,​Long,​Flux<ByteBuffer>> onDownloadErrorResume,
                                                           int maxRetries)
        Creates a Flux that is capable of resuming a download by applying retry logic when an error occurs.
        Parameters:
        downloadSupplier - Supplier of the initial download.
        onDownloadErrorResume - BiFunction of Throwable and Long which is used to resume downloading when an error occurs.
        maxRetries - The maximum number of times a download can be resumed when an error occurs.
        Returns:
        A Flux that downloads reliably.

      • createRetriableDownloadFlux

        public static Flux<ByteBuffer> createRetriableDownloadFlux​(Supplier<Flux<ByteBuffer>> downloadSupplier,
                                                           BiFunction<Throwable,​Long,​Flux<ByteBuffer>> onDownloadErrorResume,
                                                           int maxRetries,
                                                           long position)
        Creates a Flux that is capable of resuming a download by applying retry logic when an error occurs.
        Parameters:
        downloadSupplier - Supplier of the initial download.
        onDownloadErrorResume - BiFunction of Throwable and Long which is used to resume downloading when an error occurs.
        maxRetries - The maximum number of times a download can be resumed when an error occurs.
        position - The initial offset for the download.
        Returns:
        A Flux that downloads reliably.

      • 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

      • 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.

      • 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.