Package java.io

Class PipedOutputStream

java.lang.Object

java.io.OutputStream

java.io.PipedOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class PipedOutputStream
extends OutputStream

Places information on a communications pipe. When two threads want to pass data back and forth, one creates a piped output stream and the other one creates a piped input stream.

See Also:

PipedInputStream

Constructor Summary

Constructors

Constructor	Description
PipedOutputStream()	Constructs a new unconnected PipedOutputStream.
PipedOutputStream(PipedInputStream target)	Constructs a new PipedOutputStream connected to the PipedInputStream target.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this stream.
void	connect(PipedInputStream stream)	Connects this stream to a PipedInputStream.
void	flush()	Notifies the readers of this PipedInputStream that bytes can be read.
void	write(byte[] buffer, int offset, int count)	Writes count bytes from the byte array buffer starting at offset to this stream.
void	write(int oneByte)	Writes a single byte to this stream.

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Constructor Details

PipedOutputStream

public PipedOutputStream()

Constructs a new unconnected PipedOutputStream. The resulting stream must be connected to a PipedInputStream before data can be written to it.

PipedOutputStream

public PipedOutputStream(PipedInputStream target)
                  throws IOException

Constructs a new PipedOutputStream connected to the PipedInputStream target. Any data written to this stream can be read from the target stream.

Parameters:

target - the piped input stream to connect to.

Throws:

IOException - if this stream or target are already connected.

Method Details

close

public void close()
           throws IOException

Closes this stream. If this stream is connected to an input stream, the input stream is closed and the pipe is disconnected.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if an error occurs while closing this stream.

connect

public void connect(PipedInputStream stream)
             throws IOException

Connects this stream to a PipedInputStream. Any data written to this output stream becomes readable in the input stream.

Parameters:

stream - the piped input stream to connect to.

Throws:

IOException - if either stream is already connected.

flush

public void flush()
           throws IOException

Notifies the readers of this PipedInputStream that bytes can be read. This method does nothing if this stream is not connected.

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - if an I/O error occurs while flushing this stream.

write

public void write(byte[] buffer,
int offset,
int count)
           throws IOException

Writes count bytes from the byte array buffer starting at offset to this stream. The written data can then be read from the connected input stream.

Separate threads should be used to write to a PipedOutputStream and to read from the connected PipedInputStream. If the same thread is used, a deadlock may occur.

Overrides:

write in class OutputStream

Parameters:

buffer - the buffer to write.

offset - the index of the first byte in buffer to write.

count - the number of bytes from buffer to write to this stream.

Throws:

IndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is bigger than the length of buffer.

InterruptedIOException - if the pipe is full and the current thread is interrupted waiting for space to write data. This case is not currently handled correctly.

IOException - if this stream is not connected, if the target stream is closed or if the thread reading from the target stream is no longer alive. This case is currently not handled correctly.

write

public void write(int oneByte)
           throws IOException

Writes a single byte to this stream. Only the least significant byte of the integer oneByte is written. The written byte can then be read from the connected input stream.

Separate threads should be used to write to a PipedOutputStream and to read from the connected PipedInputStream. If the same thread is used, a deadlock may occur.

Specified by:

write in class OutputStream

Parameters:

oneByte - the byte to write.

Throws:

InterruptedIOException - if the pipe is full and the current thread is interrupted waiting for space to write data. This case is not currently handled correctly.

IOException - if this stream is not connected, if the target stream is closed or if the thread reading from the target stream is no longer alive. This case is currently not handled correctly.