[Chapter 11] PipedWriter

Synopsis

Class Name:

java.io.PipedWriter

Superclass:

java.io.Writer

Immediate Subclasses:

None

Interfaces Implemented:

None

Availability:

New as of JDK 1.1

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

The PipedWriter class is the character-based equivalent of the byte-based PipedOutputStream.

Class Summary

public class java.io.PipedWriter extends java.io.Writer {
  // Constructors
  public PipedWriter();
  public PipedWriter(PipedReader sink);
  // Instance Methods
  public void close();
  public void connect(PipedReader sink);
  public void flush();
  public void write(char[] cbuf, int off, int len;
}

Constructors

PipedWriter

public PipedWriter()

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

public PipedWriter(PipedReader sink)

Parameters

sink: The PipedReader to connect.

Throws

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

Description

This constructor creates a PipedWriter that sends data to the given PipedReader.

Instance Methods

close

public void close() throws IOException

Throws

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

Overrides

Writer.close()

Description

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

connect

public void connect(PipedReader sink) throws IOException

Parameters

sink: The PipedReader to connect.

Throws

IOException: If another PipedReader is already connected to this PipedWriter or this PipedWriter is already connected.

Description

This method connects this PipedWriter object to the given PipedReader. If this PipedWriter or sink is already connected, an exception is thrown.

flush

public void flush() throws IOException

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

Writer.flush()

Description

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

write

 public void write(char[] cbuf, int off, int len) throws IOException

Parameters

cbuf

An array of characters to write to the stream.

off

An offset into the character array.

len

The number of characters to write.

Throws

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

Overrides

Writer.write(char[], int, int)

Description

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

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(int)`	`Writer`
`write(char[])`	`Writer`	`write(String)`	`Writer`
`write(String, int, int)`	`Writer`


PipedReader		PrintStream