com.topcoder.file.split
Class FileJoiner

java.lang.Object
  com.topcoder.file.split.FileJoiner

public class FileJoiner
extends java.lang.Object

This class facilitates rejoining pieces of a file (split files) together to recreate the original file. Methods here provide a means to join multiple files created by a FileSplitter back into one file.

Version:

1.0

Author:

srowen, npe

Constructor Summary

FileJoiner(java.io.File firstSplitFile)
Creates a FileJoiner from the given first split file.

Method Summary

java.io.File[]	getExpectedSplitFiles() Returns the split files that are expected by this object, and that will be joined, by parsing the header in the first split file.
java.io.File	getFirstSplitFile()
java.io.File	join() This method joins smaller files into one large file.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileJoiner

public FileJoiner(java.io.File firstSplitFile)

Creates a FileJoiner from the given first split file.

Throws:

java.lang.IllegalArgumentException - if the first split file argument is null

Method Detail

getFirstSplitFile

public java.io.File getFirstSplitFile()

Returns:

first split file used by this object

join

public java.io.File join()
                  throws java.io.IOException,
                         InvalidSplitFileHeaderException

This method joins smaller files into one large file.

It reads metadata about the split files (name of the original file, number of split files, format of their names, etc.) from the first split file given to this FileJoiner object.

A file is created with the same name as the original file (read from the metadata); all the split files are located, and their data is put into the joined file, in order.

If an error occurs while joining the file, this method attempts to delete the partially joined file.

Returns:

joined file

Throws:

InvalidSplitFileHeaderException - if the first split file's header is not valid

java.io.FileNotFoundException - if the given first split file does not exist

java.io.IOException - if an exception occurs while reading/writing file data, or if the join file already exists or is not writable for any reason

getExpectedSplitFiles

public java.io.File[] getExpectedSplitFiles()
                                     throws java.io.IOException,
                                            InvalidSplitFileHeaderException

Returns the split files that are expected by this object, and that will be joined, by parsing the header in the first split file.

Returns:

the split files that are expected by this object

Throws:

InvalidSplitFileHeaderException - if the first split file's header is not valid

java.io.IOException - if an error occurs while trying to determine what split files are expected