org.openorb.util
Class DiffFileOutputStream

java.lang.Object
  |
  +--java.io.OutputStream
        |
        +--org.openorb.util.DiffFileOutputStream

public class DiffFileOutputStream

extends OutputStream

Non-clobbering file output stream. This behaves similarly to the standard java.io.FileOutputStream, however if the file already exists it will not touch the file unless the data being written is different to the current file contents. Note that care must be taken to always close the output stream, if this does not occour and the class is not garbage collected it can leave data from the old file at the end of the new file.

Version:

$Revision: 1.8 $ $Date: 2004/02/10 22:11:50 $

Author:

Chris Wood

Constructor Summary

DiffFileOutputStream(File file)
Construct a new diff output stream

DiffFileOutputStream(String filename)
Construct a new diff output stream

Method Summary

void	close() Closes the output stream and releases any system resources associated with this stream.
static boolean	copyFileNoClobber(File src, File dest) Perform a non-clobbering copy.
static boolean	copyFileNoClobber(String src, String dest) Perform a non-clobbering copy.
boolean	isWriting() Returns true if the output stream is now in write mode, and the file is being overwritten.
static void	main(String[] args)
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this file output stream.
void	write(int b) Writes the specified byte to this output stream.

Methods inherited from class java.io.OutputStream

flush, write

Methods inherited from class java.lang.Object

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

Constructor Detail

DiffFileOutputStream

public DiffFileOutputStream(File file)
                     throws FileNotFoundException

Construct a new diff output stream

Parameters:

file - the file to be written to.

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

DiffFileOutputStream

public DiffFileOutputStream(String filename)
                     throws FileNotFoundException

Construct a new diff output stream

Parameters:

filename - the name of the file.

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

Method Detail

copyFileNoClobber

public static boolean copyFileNoClobber(File src,
                                        File dest)
                                 throws IOException

Perform a non-clobbering copy. This will copy the contents of one file into the other, but only if the two files differ.

Parameters:

src - the source file.

dest - the destination file.

Returns:

true if the file was clobbered.

Throws:

IOException - if an IOException occours.

copyFileNoClobber

public static boolean copyFileNoClobber(String src,
                                        String dest)
                                 throws IOException

Perform a non-clobbering copy. This will copy the contents of one file into the other, but only if the two files differ.

Parameters:

src - the source file.

dest - the destination file.

Returns:

true if the file was clobbered.

Throws:

IOException - if an IOException occours.

isWriting

public boolean isWriting()

Returns true if the output stream is now in write mode, and the file is being overwritten.

write

public void write(int b)
           throws IOException

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Subclasses of OutputStream must provide an implementation for this method.

Overrides:

write in class OutputStream

Parameters:

b - the byte.

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

write

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

Writes len bytes from the specified byte array starting at offset off to this file output stream.

Overrides:

write in class OutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Closes the output stream and releases any system resources associated with this stream. This file output stream may no longer be used for writing bytes.

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

main

public static void main(String[] args)
                 throws IOException