de.unkrig.commons.io

Class OutputStreams

java.lang.Object

de.unkrig.commons.io.OutputStreams

public final class OutputStreams
extends Object

Utility functionality related to OutputStreams.

Field Summary

Fields

Modifier and Type	Field and Description
static OutputStream	DISCARD An OutputStream that discards all bytes written to it.

Method Summary

Modifier and Type	Method and Description
static OutputStream	byteConsumerOutputStream(ConsumerWhichThrows<? super Byte,? extends IOException> delegate)
static OutputStream[]	compareOutput(int n, Runnable whenIdentical, Runnable whenNotIdentical) Creates and returns an array of n OutputStreams.
static void	fill(OutputStream outputStream, byte b, long count) Writes count bytes of value b to the given outputStream.
static OutputStream	lengthWritten(Consumer<? super Integer> delegate) Creates and returns an OutputStream which ignores the data written to it and only honors the number of bytes written: Every time data is written to the OutputStream, it invokes the consume() method on the delegate with the number of bytes written (not the cumulated number of bytes written!).
static OutputStream	split(ProducerWhichThrows<? extends OutputStream,? extends IOException> delegates, Producer<? extends Long> byteCountLimits) Creates and returns an OutputStream which writes at most byteCountLimits.produce() bytes to delegates.produce() before closing it and writing the next byteCountLimits.produce() bytes to delegates.produce(), and so on.
static OutputStream	tee(OutputStream... delegates) Creates and returns an OutputStream that delegates all work to the given delegates: The write() methods write the given data to all the delegates; if any of these throw an IOException, it is rethrown, and it is undefined whether all the data was written to all the delegates.
static OutputStream	unclosable(OutputStream delegate)
static OutputStream	unclosableOutputStream(OutputStream delegate) Deprecated. Use unclosable(OutputStream) instead
static long	writeAndCount(ConsumerWhichThrows<? super OutputStream,? extends IOException> writeContents, OutputStream outputStream) Invokes writeContents.consume() with an output stream subject that writes the data through to the given outputStream.

Methods inherited from class java.lang.Object

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

Field Detail

DISCARD

public static final OutputStream DISCARD

An OutputStream that discards all bytes written to it.

Method Detail

tee

public static OutputStream tee(OutputStream... delegates)

Creates and returns an OutputStream that delegates all work to the given delegates:

• The write() methods write the given data to all the delegates; if any of these throw an IOException, it is rethrown, and it is undefined whether all the data was written to all the delegates.
• flush() flushes the delegates; throws the first IOException that any of the delegates throws.
• close() attempts to close all the delegates; if any of these throw IOExceptions, one of them is rethrown.

writeAndCount

public static long writeAndCount(ConsumerWhichThrows<? super OutputStream,? extends IOException> writeContents,
                                 OutputStream outputStream)
                          throws IOException

Invokes writeContents.consume() with an output stream subject that writes the data through to the given outputStream.

Returns:

The number of bytes that were written through

Throws:

IOException

split

public static OutputStream split(ProducerWhichThrows<? extends OutputStream,? extends IOException> delegates,
                                 Producer<? extends Long> byteCountLimits)
                          throws IOException

Creates and returns an OutputStream which writes at most byteCountLimits.produce() bytes to delegates.produce() before closing it and writing the next byteCountLimits.produce() bytes to delegates.produce(), and so on.

Parameters:

delegates - Must produce a (non-null) series of OutputStreams

byteCountLimits - Must produce a (non-null) series of Longs

Throws:

IOException

unclosableOutputStream

@Deprecated
public static OutputStream unclosableOutputStream(OutputStream delegate)

Deprecated. Use unclosable(OutputStream) instead

Returns:

An OutputStream which ignores all invocations of OutputStream.close()

unclosable

public static OutputStream unclosable(OutputStream delegate)

Returns:

An OutputStream which ignores all invocations of OutputStream.close()

fill

public static void fill(OutputStream outputStream,
                        byte b,
                        long count)
                 throws IOException

Writes count bytes of value b to the given outputStream.

Throws:

IOException

byteConsumerOutputStream

public static OutputStream byteConsumerOutputStream(ConsumerWhichThrows<? super Byte,? extends IOException> delegate)

Returns:

An output stream which feeds the data to the delegate byte consumer

compareOutput

public static OutputStream[] compareOutput(int n,
                                           Runnable whenIdentical,
                                           Runnable whenNotIdentical)

Creates and returns an array of n OutputStreams.

Iff exactly the same bytes are written to all of these streams, and then all the streams are closed, then whenIdentical will be run (exactly once).

Otherwise, when the first non-identical byte is written to one of the streams, or at the latest when that stream is closed, whenNotIdentical will be run (possibly more than once).

lengthWritten

public static OutputStream lengthWritten(Consumer<? super Integer> delegate)

Creates and returns an OutputStream which ignores the data written to it and only honors the number of bytes written:

Every time data is written to the OutputStream, it invokes the consume() method on the delegate with the number of bytes written (not the cumulated number of bytes written!).