com.speedment.runtime.core.util

Class StreamComposition

java.lang.Object

com.speedment.runtime.core.util.StreamComposition

public class StreamComposition
extends Object

Utility methods for making sure composed streams are closed properly.

Author:

Per Minborg

Constructor Summary

Constructors

Constructor and Description
StreamComposition()

Method Summary

Modifier and Type	Method and Description
static <T> Stream<T>	concat(Stream<T>... streams) Creates a concatenated Stream whose elements are are all the elements of the streams in sequential order.
static <T> Stream<T>	concatAndAutoClose(Stream<T>... streams) Creates a lazily concatenated Stream whose elements are are all the elements of the streams in sequential order.

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamComposition

public StreamComposition()

Method Detail

concatAndAutoClose

@SafeVarargs
public static <T> Stream<T> concatAndAutoClose(Stream<T>... streams)

Creates a lazily concatenated Stream whose elements are are all the elements of the streams in sequential order. The resulting Stream is ordered if all of the input streams are ordered, and parallel if at least one of the input streams are parallel. When a terminating operation is called, all the streams are automatically and explicitly closed, whereby their close handlers are invoked. AutoClosing is performed in sequential order too. If a Stream throws an Exception, it is still guaranteed that all Streams' close methods are called.

Streams are processed one at at time. When one is exhausted, a new one will start. Parallelism is only supported within the individual streams provided.

N.B. a stream's close method may be called even through that stream never produced any output, if a preceding stream threw an Exception.

N.B. an UnsupportedOperationException will be thrown if the concatenated stream's BaseStream.iterator() or BaseStream.spliterator() methods are called, because they could potentially violate the resulting Stream's AutoClose property.

N.B. Use caution when constructing streams from repeated concatenation. Accessing an element of a deeply concatenated stream can result in deep call chains, or even StackOverflowException.

Type Parameters:

T - The type of stream elements

Parameters:

streams - to concatenate

Returns:

the concatenation of the input streams

Throws:

UnsupportedOperationException - if the concatenated stream's BaseStream.iterator() or BaseStream.spliterator() methods are called, because they could potentially violate the resulting Stream's AutoClose property.

concat

@SafeVarargs
public static <T> Stream<T> concat(Stream<T>... streams)

Creates a concatenated Stream whose elements are are all the elements of the streams in sequential order. The resulting Stream is ordered if all of the input streams are ordered, and parallel if at least one of the input streams are parallel.

Streams are processed one at at time. When one is exhausted, a new one will start. Parallelism is only supported within the individual streams provided.

N.B. Use caution when constructing streams from repeated concatenation. Accessing an element of a deeply concatenated stream can result in deep call chains, or even StackOverflowException.

Type Parameters:

T - The type of stream elements

Parameters:

streams - to concatenate

Returns:

the concatenation of the input streams