OpenJDK 1.23 · java.util.stream.BaseStream · APIdia, the JavaDoc alternative

Base interface for streams, which are sequences of elements supporting sequential and parallel aggregate operations. The following example illustrates an aggregate operation using the stream types Stream and IntStream, computing the sum of the weights of the red widgets:

int sum = widgets.stream()
                     .filter(w -> w.getColor() == RED)
                     .mapToInt(w -> w.getWeight())
                     .sum();

See the class documentation for Stream and the package documentation for java.util.stream for additional specification of streams, stream operations, stream pipelines, and parallelism, which governs the behavior of all stream types.

Method Summary

Modifier and Type	Method and Description
public void	close() Redeclares java.lang.AutoCloseable.close. Closes this stream, causing all close handlers for this stream pipeline to be called.
public boolean	Returns: `true` if this stream would execute in parallel if executed isParallel() Returns whether this stream, if a terminal operation were to be executed, would execute in parallel.
public Iterator<T>	Returns: the element iterator for this stream iterator() Returns an iterator for the elements of this stream.
public S	Returns: a stream with a handler that is run if the stream is closed onClose(Runnable A task to execute when the stream is closed closeHandler) Returns an equivalent stream with an additional close handler.
public S	Returns: a parallel stream parallel() Returns an equivalent stream that is parallel.
public S	Returns: a sequential stream sequential() Returns an equivalent stream that is sequential.
public Spliterator<T>	Returns: the element spliterator for this stream spliterator() Returns a spliterator for the elements of this stream.
public S	Returns: an unordered stream unordered() Returns an equivalent stream that is unordered.

Method Detail

close back to summary

close	back to summary
public void close() Redeclares java.lang.AutoCloseable.close. Closes this stream, causing all close handlers for this stream pipeline to be called. Annotations @Override See Also `AutoCloseable#close()`

public void close()

Redeclares java.lang.AutoCloseable.close.

Closes this stream, causing all close handlers for this stream pipeline to be called.

Annotations

@Override

See Also

AutoCloseable#close()

isParallel back to summary

isParallel	back to summary
public boolean isParallel() Returns whether this stream, if a terminal operation were to be executed, would execute in parallel. Calling this method after invoking an terminal stream operation method may yield unpredictable results. Returns:boolean `true` if this stream would execute in parallel if executed

public boolean isParallel()

Returns whether this stream, if a terminal operation were to be executed, would execute in parallel. Calling this method after invoking an terminal stream operation method may yield unpredictable results.

Returns:boolean: true if this stream would execute in parallel if executed

iterator	back to summary
public Iterator<T> iterator() Returns an iterator for the elements of this stream. This is a terminal operation. API Note This operation is provided as an "escape hatch" to enable arbitrary client-controlled pipeline traversals in the event that the existing operations are not sufficient to the task. Returns:Iterator<T> the element iterator for this stream

iterator

back to summary

public Iterator<T> iterator()

Returns an iterator for the elements of this stream.

This is a terminal operation.

API Note

This operation is provided as an "escape hatch" to enable arbitrary client-controlled pipeline traversals in the event that the existing operations are not sufficient to the task.

Returns:Iterator<T>: the element iterator for this stream

onClose back to summary

onClose	back to summary
public S onClose(Runnable closeHandler) Returns an equivalent stream with an additional close handler. Close handlers are run when the `close()` method is called on the stream, and are executed in the order they were added. All close handlers are run, even if earlier close handlers throw exceptions. If any close handler throws an exception, the first exception thrown will be relayed to the caller of `close()`, with any remaining exceptions added to that exception as suppressed exceptions (unless one of the remaining exceptions is the same exception as the first exception, since an exception cannot suppress itself.) May return itself. This is an intermediate operation. Parameters closeHandler:Runnable A task to execute when the stream is closed Returns:S a stream with a handler that is run if the stream is closed

public S onClose(Runnable closeHandler)

Returns an equivalent stream with an additional close handler. Close handlers are run when the close() method is called on the stream, and are executed in the order they were added. All close handlers are run, even if earlier close handlers throw exceptions. If any close handler throws an exception, the first exception thrown will be relayed to the caller of close(), with any remaining exceptions added to that exception as suppressed exceptions (unless one of the remaining exceptions is the same exception as the first exception, since an exception cannot suppress itself.) May return itself.

This is an intermediate operation.

Parameters

closeHandler:Runnable: A task to execute when the stream is closed

Returns:S

a stream with a handler that is run if the stream is closed

parallel	back to summary
public S parallel() Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel. This is an intermediate operation. Returns:S a parallel stream

parallel

back to summary

public S parallel()

Returns an equivalent stream that is parallel. May return itself, either because the stream was already parallel, or because the underlying stream state was modified to be parallel.

This is an intermediate operation.

Returns:S: a parallel stream

sequential	back to summary
public S sequential() Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential. This is an intermediate operation. Returns:S a sequential stream

sequential

back to summary

public S sequential()

Returns an equivalent stream that is sequential. May return itself, either because the stream was already sequential, or because the underlying stream state was modified to be sequential.

This is an intermediate operation.

Returns:S: a sequential stream

spliterator	back to summary
public Spliterator<T> spliterator() Returns a spliterator for the elements of this stream. This is a terminal operation. API Note This operation is provided as an "escape hatch" to enable arbitrary client-controlled pipeline traversals in the event that the existing operations are not sufficient to the task. The returned spliterator should report the set of characteristics derived from the stream pipeline (namely the characteristics derived from the stream source spliterator and the intermediate operations). Implementations may report a sub-set of those characteristics. For example, it may be too expensive to compute the entire set for some or all possible stream pipelines. Returns:Spliterator<T> the element spliterator for this stream

spliterator

back to summary

public Spliterator<T> spliterator()

Returns a spliterator for the elements of this stream.

This is a terminal operation.

API Note

This operation is provided as an "escape hatch" to enable arbitrary client-controlled pipeline traversals in the event that the existing operations are not sufficient to the task.

The returned spliterator should report the set of characteristics derived from the stream pipeline (namely the characteristics derived from the stream source spliterator and the intermediate operations). Implementations may report a sub-set of those characteristics. For example, it may be too expensive to compute the entire set for some or all possible stream pipelines.

Returns:Spliterator<T>: the element spliterator for this stream

unordered	back to summary
public S unordered() Returns an equivalent stream that is unordered. May return itself, either because the stream was already unordered, or because the underlying stream state was modified to be unordered. This is an intermediate operation. Returns:S an unordered stream

unordered

back to summary

public S unordered()

Returns an equivalent stream that is unordered. May return itself, either because the stream was already unordered, or because the underlying stream state was modified to be unordered.

This is an intermediate operation.

Returns:S: an unordered stream

public Interface BaseStream<T, S extends BaseStream<T, S>>

Method Summary

Method Detail