tribble.io
Class SuspendableWriter

java.lang.Object
  java.io.Writer
      tribble.io.SuspendableWriter

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.Appendable, SuspendableWriterI

public class SuspendableWriter
extends java.io.Writer
implements SuspendableWriterI

A character output stream that can be suspended and resumed.

This is a default implementation of a character output stream that can be suspended and resumed (see SuspendableWriterI), based on the standard Writer class. It provides the capability of suspending all output written to the stream, so that subsequent write requests perform no output. It also has the capability of resuming all output written to the stream.

Since:

2001-06-21

Version:

$Revision: 1.1 $ $Date: 2001/09/01 17:59:40 $

Author:

David R. Tribble, david@tribble.com.
Copyright ©2001 by David R. Tribble, all rights reserved.
Permission is granted to freely use and distribute this source code provided that the original copyright and authorship notices remain intact.

See Also:

Writer

Field Summary

protected static java.lang.String	EXCEPT_CLOSED Exception text contents for a closed output stream.
protected java.io.Writer	m_out Underlying output stream.
protected java.io.Writer	m_sus Suspended underlying output stream.
(package private) static java.lang.String	REV Revision information.

Fields inherited from class java.io.Writer

lock

Constructor Summary

SuspendableWriter()
Constructor.

SuspendableWriter(java.io.Writer out)
Constructor.

Method Summary

void	close() Closes this output stream.
protected void	finalize() Finalization.
void	flush() Flushes any pending output to the output stream.
java.io.Writer	getOutput() Retrieves the underlying output stream to which all output for this stream is written.
boolean	isSuspended() Determines if this output stream is suspended or not.
void	resume() Resumes subsequent output written to this output stream.
void	setOutput(java.io.Writer out) Establishes the underlying output stream to which all output for this stream is written.
void	suspend() Suspends subsequent output written to this output stream.
void	write(char[] cbuf) Writes the contents of a character array to this output stream.
void	write(char[] cbuf, int off, int len) Writes a portion of a character array to this output stream.
void	write(int c) Writes a single character to this output stream.
void	write(java.lang.String str) Writes the contents of a string to this output stream.
void	write(java.lang.String str, int off, int len) Writes a subset of a string to this output stream.

Methods inherited from class java.io.Writer

append, append, append

Methods inherited from class java.lang.Object

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

Field Detail

REV

static final java.lang.String REV

Revision information.

See Also:

Constant Field Values

EXCEPT_CLOSED

protected static final java.lang.String EXCEPT_CLOSED

Exception text contents for a closed output stream.

See Also:

Constant Field Values

m_out

protected java.io.Writer m_out

Underlying output stream.

m_sus

protected java.io.Writer m_sus

Suspended underlying output stream.

Constructor Detail

SuspendableWriter

public SuspendableWriter()

Constructor.

Since:

1.1, 2001-06-21

SuspendableWriter

public SuspendableWriter(java.io.Writer out)

Constructor. Establishes the underlying output stream to which all output for this stream is written.

Parameters:

out - The underlying output stream for this stream.

Since:

1.1, 2001-06-21

Method Detail

suspend

public void suspend()

Suspends subsequent output written to this output stream.

Output to this stream can be resumed by calling resume().

This method may be called multiple times without any intervening call to resume() without any ill effects.

Specified by:

suspend in interface SuspendableWriterI

Since:

1.1, 2001-06-21

See Also:

resume()

resume

public void resume()

Resumes subsequent output written to this output stream.

Output to this stream can be suspended by calling suspend().

This method may be called multiple times without any previous or intervening call to suspend() without any ill effects.

Specified by:

resume in interface SuspendableWriterI

Since:

1.1, 2001-06-21

See Also:

suspend()

isSuspended

public boolean isSuspended()

Determines if this output stream is suspended or not.

Specified by:

isSuspended in interface SuspendableWriterI

Returns:

True if this output stream is currently suspended, otherwise false.

Since:

1.1, 2001-09-01

See Also:

suspend()

close

public void close()
           throws java.io.IOException

Closes this output stream.

Note that this method is required to flush and close the underlying output stream of this stream. Any writes subsequent to closing this stream should throw an IOException exception.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface SuspendableWriterI

Specified by:

close in class java.io.Writer

Throws:

java.io.IOException - Thrown if an output error occurs.

Since:

1.1, 2001-06-21

flush

public void flush()
           throws java.io.IOException

Flushes any pending output to the output stream.

Specified by:

flush in interface java.io.Flushable

Specified by:

flush in class java.io.Writer

Throws:

java.io.IOException - Thrown if an output error occurs.

Since:

1.1, 2001-06-21

write

public void write(char[] cbuf)
           throws java.io.IOException

Writes the contents of a character array to this output stream.

Overrides:

write in class java.io.Writer

Parameters:

cbuf - A character buffer to write.

Throws:

java.io.IOException - Thrown if an output error occurs, or if this output stream is closed.

Since:

1.1, 2001-06-21

write

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

Writes a portion of a character array to this output stream.

Specified by:

write in class java.io.Writer

Parameters:

cbuf - A character buffer, from which a subset of characters is written.

off - The offset of the first character within character buffer cbuf to write.

len - The number of characters from character buffer cbuf to write.

Throws:

java.io.IOException - Thrown if an output error occurs, or if this output stream is closed.

Since:

1.1, 2001-06-21

write

public void write(java.lang.String str)
           throws java.io.IOException

Writes the contents of a string to this output stream.

Overrides:

write in class java.io.Writer

Parameters:

str - A string to write.

Throws:

java.io.IOException - Thrown if an output error occurs, or if this output stream is closed.

Since:

1.1, 2001-06-21

write

public void write(java.lang.String str,
                  int off,
                  int len)
           throws java.io.IOException

Writes a subset of a string to this output stream.

Overrides:

write in class java.io.Writer

Parameters:

str - A string containing the substring to write.

off - The offset of the first character within the string to write.

len - The number of characters from the substring to write.

Throws:

java.io.IOException - Thrown if an output error occurs, or if this output stream is closed.

Since:

1.1, 2001-06-21

write

public void write(int c)
           throws java.io.IOException

Writes a single character to this output stream.

Overrides:

write in class java.io.Writer

Parameters:

c - A character code to write.

Throws:

java.io.IOException - Thrown if an output error occurs, or if this output stream is closed.

Since:

1.1, 2001-06-21

setOutput

public void setOutput(java.io.Writer out)

Establishes the underlying output stream to which all output for this stream is written.

Parameters:

out - The underlying output stream for this stream.

Since:

1.1, 2001-06-21

getOutput

public java.io.Writer getOutput()

Retrieves the underlying output stream to which all output for this stream is written.

Returns:

The underlying output stream of this stream.

Since:

1.1, 2001-06-21

finalize

protected void finalize()
                 throws java.lang.Throwable

Finalization.

Flushes, but does not close, the underlying output stream (if there is one), and then disassociates it from this output stream.

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable - Thrown if an error occurs.

Since:

1.1, 2001-06-21