Class PipedOutputStream

java.lang.Object

java.io.OutputStream

java.io.PipedOutputStream

All Implemented Interfaces:: Closeable, Flushable, AutoCloseable

public class PipedOutputStream extends OutputStream

A piped output stream can be connected to a piped input stream to create a communications pipe. The piped output stream is the sending end of the pipe. Typically, data is written to a PipedOutputStream object by one thread and data is read from the connected PipedInputStream by some other thread. Attempting to use both objects from a single thread is not recommended as it may deadlock the thread. The pipe is said to be broken if a thread that was reading data bytes from the connected piped input stream is no longer alive.

Since:

1.0

See Also:

Constructor Summary

Constructor	Description
`PipedOutputStream()`	Creates a piped output stream that is not yet connected to a piped input stream.
`PipedOutputStream(PipedInputStream snk)`	Creates a piped output stream connected to the specified piped input stream.

Method Summary

Modifier and Type	Method	Description
`void`	`close()`	Closes this piped output stream and releases any system resources associated with this stream.
`void`	`connect(PipedInputStream snk)`	Connects this piped output stream to a receiver.
`void`	`flush()`	Flushes this output stream and forces any buffered output bytes to be written out.
`void`	`write(byte[] b, int off, int len)`	Writes `len` bytes from the specified byte array starting at offset `off` to this piped output stream.
`void`	`write(int b)`	Writes the specified `byte` to the piped output stream.

Methods declared in class OutputStream

nullOutputStream, write

Modifier and Type	Method	Description
`static OutputStream`	`nullOutputStream()`	Returns a new `OutputStream` which discards all bytes.
`void`	`write(byte[] b)`	Writes `b.length` bytes from the specified byte array to this output stream.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

PipedOutputStream

public PipedOutputStream(PipedInputStream snk) throws IOException

Creates a piped output stream connected to the specified piped input stream. Data bytes written to this stream will then be available as input from snk.

Parameters:: snk - The piped input stream to connect to.
Throws:: IOException - if an I/O error occurs.

PipedOutputStream

public PipedOutputStream()

Creates a piped output stream that is not yet connected to a piped input stream. It must be connected to a piped input stream, either by the receiver or the sender, before being used.

See Also:

Method Details

connect

public void connect(PipedInputStream snk) throws IOException

Connects this piped output stream to a receiver. If this object is already connected to some other piped input stream, an IOException is thrown.

If snk is an unconnected piped input stream and src is an unconnected piped output stream, they may be connected by either the call:

    src.connect(snk)

or the call:

    snk.connect(src)

The two calls have the same effect.

Parameters:: snk - the piped input stream to connect to.
Throws:: IOException - if an I/O error occurs.

write

public void write(int b) throws IOException

Writes the specified byte to the piped output stream.

Implements the write method of OutputStream.

Specified by:: write in class OutputStream
Parameters:: b - the byte to be written.
Throws:: IOException - if the pipe is broken, unconnected, closed, or if an I/O error occurs.

write

public void write(byte[] b, int off, int len) throws IOException

Writes len bytes from the specified byte array starting at offset off to this piped output stream. If len is not zero, this method blocks until all the bytes are written to the output stream.

Overrides:: write in class OutputStream
Parameters:: b - the data.; off - the start offset in the data.; len - the number of bytes to write.
Throws:: IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off; IOException - if the pipe is broken, unconnected, closed and len is greater than zero, or if an I/O error occurs.

flush

public void flush() throws IOException

Flushes this output stream and forces any buffered output bytes to be written out. This will notify any readers that bytes are waiting in the pipe.

Specified by:: flush in interface Flushable
Overrides:: flush in class OutputStream
Throws:: IOException - if an I/O error occurs.

close

public void close() throws IOException

Closes this piped output stream and releases any system resources associated with this stream. This stream may no longer be used for writing bytes.

Specified by:: close in interface AutoCloseable
Specified by:: close in interface Closeable
Overrides:: close in class OutputStream
Throws:: IOException - if an I/O error occurs.

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.