org.apache.commons.io.output
Class LockableFileWriter

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

public class LockableFileWriter

extends java.io.Writer

FileWriter that will create and honor lock files to allow simple cross thread file lock handling. If Writer attributes are unspecified, the default behavior is to overwrite (rather than to append), and to use the value of the system property java.io.tmpdir for the lock file directory.

Version:

$Id: LockableFileWriter.java,v 1.6 2003/12/30 15:19:59 jeremias Exp $

Author:

Scott Sanders, Michael Salmon, Jon S. Stevens, Daniel Rall

Field Summary

private boolean	append
private static java.lang.String	LCK
private java.io.File	lockFile
private java.io.FileWriter	writer

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.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()
private void	createLock()
void	flush()
private void	testLockDir(java.io.File lockDir)
void	write(char[] cbuf, int off, int len)

Methods inherited from class java.io.Writer

write, write, write, write

Methods inherited from class java.lang.Object

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

Field Detail

LCK

private static final java.lang.String LCK

See Also:

Constant Field Values

lockFile

private java.io.File lockFile

writer

private java.io.FileWriter writer

append

private boolean append

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 - file to write to

Throws:

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

append - true if content should be appended (default is to overwrite).

Throws:

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 - file to write to

append - true if content should be appended (default is to overwrite).

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

Throws:

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 - file to write to

Throws:

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 - file to write to

append - true if content should be appended (default is to overwrite).

Throws:

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 - file to write to

append - true if content should be appended (default is to overwrite).

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

Throws:

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

Method Detail

testLockDir

private void testLockDir(java.io.File lockDir)
                  throws java.io.IOException

Throws:

java.io.IOException

createLock

private void createLock()
                 throws java.io.IOException

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Throws:

java.io.IOException

See Also:

Writer.close()

write

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

Throws:

java.io.IOException

See Also:

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

flush

public void flush()
           throws java.io.IOException

Throws:

java.io.IOException

See Also:

Writer.flush()