de.hpi.fgis.dude.util.sorting.sorter
Class SortedDataFile

java.lang.Object
  de.hpi.fgis.dude.util.sorting.sorter.SortedDataFile

All Implemented Interfaces:

Closeable

public class SortedDataFile
extends Object
implements Closeable

SortedDataFile encapsulates the functionality that is needed for the TwoPhaseMultiWayMergeSorter in phase two. It provides a method for removing the file and methods for iterating over the content of the file.

Author:

Matthias Pohl

Constructor Summary

SortedDataFile(FileBasedStorage<DuDeObject> file)
Initializes a SortedDataFile and loads the first element.

Method Summary

void	close()
DuDeObject	current() Returns the element on which the iterating pointer points right now.
void	deleteFile() Deletes the file from the file system and clears the member data of this instance.
FileBasedStorage<DuDeObject>	getDataFile() Returns the FileBasedStorage that is encapsulated in this instance.
boolean	hasNext() Checks whether the end of the file is reached.
protected boolean	isAccessible() Checks whether the file can be accessed.
DuDeObject	next() Sets the the iteration pointer to the next element and returns it.

Methods inherited from class java.lang.Object

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

Constructor Detail

SortedDataFile

public SortedDataFile(FileBasedStorage<DuDeObject> file)

Initializes a SortedDataFile and loads the first element. Therefore calling next() after calling this constructor returns the second element.

Parameters:

file - The FileBasedStorage that is read.

Method Detail

current

public DuDeObject current()

Returns the element on which the iterating pointer points right now.

Returns:

The current element or null, if the end of the file is reached.

deleteFile

public void deleteFile()

Deletes the file from the file system and clears the member data of this instance.

hasNext

public boolean hasNext()

Checks whether the end of the file is reached.

Returns:

true, if this file has still data to read; otherwise false.

next

public DuDeObject next()

Sets the the iteration pointer to the next element and returns it.

Returns:

The next DuDeObject instance in this collection or null, if the end of the file is reached.

isAccessible

protected boolean isAccessible()

Checks whether the file can be accessed.

Returns:

true, if the file can be accessed; otherwise false.

getDataFile

public FileBasedStorage<DuDeObject> getDataFile()

Returns the FileBasedStorage that is encapsulated in this instance.

Returns:

The FileBasedStorage.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Throws:

IOException