Chapter 11
The java.io Package

PipedOutputStream

Name

PipedOutputStream

Synopsis

Class Name:

java.io.PipedOutputStream

Superclass:

java.io.OutputStream

Immediate Subclasses:

None

Interfaces Implemented:

None

Availability:

JDK 1.0 or later

The PipedOutputStream class represents half of a communication pipe; a PipedOutputStream must be connected to a PipedOutputStream. When the two halves of a communication pipe are connected, data written to the PipedOutputStream can be read from the PipedInputStream. The communication pipe formed by a PipedOutputStream and a PipedInputStream should be used to communicate between threads. If both ends of a pipe are used by the same thread, the thread can hang.

Class Summary

public class java.io.PipedOutputStream extends java.io.OutputStream {
  // Constructors
  public PipedOutputStream();
  public PipedOutputStream(PipedInputStream snk);
  // Instance Methods
  public void close();
  public void connect(PipedInputStream snk);
  public synchronized void flush();               // New in 1.1
  public void write(int b);
  public void write(byte[] b, int off, int len);
}

Constructors

PipedOutputStream

public PipedOutputStream()

Description: This constructor creates a PipedOutputStream that is not connected to a PipedInputStream. The created object must be connected to a PipedInputStream before it can be used.

public PipedOutputStream(PipedInputStream snk)

Parameters

snk: The PipedInputStream to connect.

Throws

IOException: If any kind of I/O error occurs.

Description

This constructor creates a PipedOutputStream that sends data to the given PipedInputStream.

Instance Methods

close

public void close() throws IOException

Throws

IOException: If any kind of I/O error occurs.

Overrides

OutputStream.close()

Description

This method closes the stream and releases the system resources that are associated with it.

connect

public void connect(PipedInputStream snk) throws IOException

Parameters

snk: The PipedInputStream to connect.

Throws

IOException: If another PipedInputStream is already connected to this PipedOutputStream or this PipedOutputStream is already connected.

Description

This method connects this PipedOutputStream object to the given PipedInputStream. If this PipedOutputStream or snk is already connected, an exception is thrown.

flush

public synchronized void flush() throws IOException

Availability

New as of JDK 1.1

Throws

IOException

If any kind of I/O error occurs.

InterruptedIOException

While this method is waiting for buffer space to become available, if the interrupted() method of the thread that invoked this method is called.

Overrides

OutputStream.flush()

Description

This method flushes the stream, which tells the connected PipedInputStream to notify its readers to read any available data.

write

public void write(int b) throws IOException

Parameters

b: The value to write.

Throws

IOException

If any kind of I/O error occurs.

InterruptedIOException

While this method is waiting for buffer space to become available, if the interrupted() method of the thread that invoked this method is called.

Overrides

OutputStream.write(int)

Description

This method writes a byte of output. The method passes the given value directly to the connected PipedInputStream.

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

Parameters

b

An array of bytes to write to the stream.

off

An offset into the byte array.

len

The number of bytes to write.

Throws

IOException

If any kind of I/O error occurs.

InterruptedIOException

While this method is waiting for buffer space to become available, if the interrupted() method of the thread that invoked this method is called.

Overrides

OutputStream.write(byte[], int, int)

Description

This method writes len bytes of output from the given array, starting at offset off. The method passes the given data to the connected PipedInputStream.

Inherited Methods

Method	Inherited From	Method	Inherited From
`clone()`	`Object`	`equals(Object)`	`Object`
`finalize()`	`Object`	`getClass()`	`Object`
`hashCode()`	`Object`	`notify()`	`Object`
`notifyAll()`	`Object`	`toString()`	`Object`
`wait()`	`Object`	`wait(long)`	`Object`
`wait(long, int)`	`Object`	`write(byte[])`	`OutputStream`