org.apache.commons.io.output
Class LockableFileWriter

java.lang.Object
  java.io.Writer
      org.apache.commons.io.output.LockableFileWriter

All Implemented Interfaces:

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

public class LockableFileWriter
extends java.io.Writer

FileWriter that will create and honor lock files to allow simple cross thread file lock handling.

This class provides a simple alternative to FileWriter that will use a lock file to prevent duplicate writes.

By default, the file will be overwritten, but this may be changed to append. The lock directory may be specified, but defaults to the system property java.io.tmpdir. The encoding may also be specified, and defaults to the platform default.

Version:

$Id: LockableFileWriter.java 437567 2006-08-28 06:39:07Z bayard $

Author:

Scott Sanders, Michael Salmon, Jon S. Stevens, Daniel Rall, Stephen Colebourne, Andy Lehane

Field Summary

Fields inherited from class java.io.Writer

lock

Constructor Summary

LockableFileWriter(java.io.File file)
Constructs a LockableFileWriter.

LockableFileWriter(java.io.File file, boolean append)
Constructs a LockableFileWriter.

LockableFileWriter(java.io.File file, boolean append, java.lang.String lockDir)
Constructs a LockableFileWriter.

LockableFileWriter(java.io.File file, java.lang.String encoding)
Constructs a LockableFileWriter with a file encoding.

LockableFileWriter(java.io.File file, java.lang.String encoding, boolean append, java.lang.String lockDir)
Constructs a LockableFileWriter with a file encoding.

LockableFileWriter(java.lang.String fileName)
Constructs a LockableFileWriter.

LockableFileWriter(java.lang.String fileName, boolean append)
Constructs a LockableFileWriter.

LockableFileWriter(java.lang.String fileName, boolean append, java.lang.String lockDir)
Constructs a LockableFileWriter.

Method Summary

void	close() Closes the file writer.
void	flush()
void	write(char[] chr)
void	write(char[] chr, int st, int end)
void	write(int idx)
void	write(java.lang.String str)
void	write(java.lang.String str, int st, int end)

Methods inherited from class java.io.Writer

append, append, append

Methods inherited from class java.lang.Object

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

Constructor Detail

LockableFileWriter

public LockableFileWriter(java.lang.String fileName)
                   throws java.io.IOException

Constructs a LockableFileWriter. If the file exists, it is overwritten.

Parameters:

fileName - the file to write to, not null

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.lang.String fileName,
                          boolean append)
                   throws java.io.IOException

Constructs a LockableFileWriter.

Parameters:

fileName - file to write to, not null

append - true if content should be appended, false to overwrite

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.lang.String fileName,
                          boolean append,
                          java.lang.String lockDir)
                   throws java.io.IOException

Constructs a LockableFileWriter.

Parameters:

fileName - the file to write to, not null

append - true if content should be appended, false to overwrite

lockDir - the directory in which the lock file should be held

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.io.File file)
                   throws java.io.IOException

Constructs a LockableFileWriter. If the file exists, it is overwritten.

Parameters:

file - the file to write to, not null

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.io.File file,
                          boolean append)
                   throws java.io.IOException

Constructs a LockableFileWriter.

Parameters:

file - the file to write to, not null

append - true if content should be appended, false to overwrite

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.io.File file,
                          boolean append,
                          java.lang.String lockDir)
                   throws java.io.IOException

Constructs a LockableFileWriter.

Parameters:

file - the file to write to, not null

append - true if content should be appended, false to overwrite

lockDir - the directory in which the lock file should be held

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.io.File file,
                          java.lang.String encoding)
                   throws java.io.IOException

Constructs a LockableFileWriter with a file encoding.

Parameters:

file - the file to write to, not null

encoding - the encoding to use, null means platform default

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

LockableFileWriter

public LockableFileWriter(java.io.File file,
                          java.lang.String encoding,
                          boolean append,
                          java.lang.String lockDir)
                   throws java.io.IOException

Constructs a LockableFileWriter with a file encoding.

Parameters:

file - the file to write to, not null

encoding - the encoding to use, null means platform default

append - true if content should be appended, false to overwrite

lockDir - the directory in which the lock file should be held

Throws:

java.lang.NullPointerException - if the file is null

java.io.IOException - in case of an I/O error

Method Detail

close

public void close()
           throws java.io.IOException

Closes the file writer.

Specified by:

close in interface java.io.Closeable

Specified by:

close in class java.io.Writer

Throws:

java.io.IOException - if an I/O error occurs

write

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

Overrides:

write in class java.io.Writer

Throws:

java.io.IOException

See Also:

Writer.write(int)

write

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

Overrides:

write in class java.io.Writer

Throws:

java.io.IOException

See Also:

Writer.write(char[])

write

public void write(char[] chr,
                  int st,
                  int end)
           throws java.io.IOException

Specified by:

write in class java.io.Writer

Throws:

java.io.IOException

See Also:

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

write

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

Overrides:

write in class java.io.Writer

Throws:

java.io.IOException

See Also:

Writer.write(String)

write

public void write(java.lang.String str,
                  int st,
                  int end)
           throws java.io.IOException

Overrides:

write in class java.io.Writer

Throws:

java.io.IOException

See Also:

Writer.write(String, int, int)

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.Flushable

Specified by:

flush in class java.io.Writer

Throws:

java.io.IOException

See Also:

Writer.flush()