Package ch.heigvd.dai.utilities

Class FileManipulator

java.lang.Object

ch.heigvd.dai.utilities.FileManipulator

public class FileManipulator
extends Object

Implements the necessary functions to read/write the bytes of the file to hide/expose.

Author:

Pedro Alves da Silva, Gonçalo Carvalheiro Heleno

Field Summary

Fields

Modifier and Type	Field	Description
private final File	file
private boolean	writeEnabled

Constructor Summary

Constructors

Constructor	Description
FileManipulator(String filename)	Main constructor.
FileManipulator(String filename, boolean writeEnabled)	Write constructor.

Method Summary

Modifier and Type	Method	Description
byte[]	readBytesFromFile()	Reads the file linked to the object and creates a byte array with its content.
void	writeBytesToFile(byte[] bytes)	Writes a byte array to a file in the given output.

Methods inherited from class java.lang.Object

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

Field Details

file

private final File file

writeEnabled

private boolean writeEnabled

Constructor Details

FileManipulator

public FileManipulator(String filename)
                throws NullPointerException

Main constructor.

Parameters:

filename - a String with the path to the file

Throws:

NullPointerException - if the filename argument is null

FileManipulator

public FileManipulator(String filename,
 boolean writeEnabled)
                throws NullPointerException

Write constructor.

Constructor used when the file is opened with write permissions. This is merely a flag we use to make sure the write function cannot be called unless the object explicitly allows it.

Parameters:

filename - a String with the path to the file

writeEnabled - a boolean to enable the writeBytesToFile(byte[]) function

Throws:

NullPointerException - if the filename argument is null

Method Details

readBytesFromFile

public byte[] readBytesFromFile()
                         throws IOException,
OutOfMemoryError

Reads the file linked to the object and creates a byte array with its content.

Returns:

a byte[] array with the contents of the file

Throws:

IOException - if there is an IO error when trying to open the file

OutOfMemoryError - if the file it too big to fit inside a byte[] array

writeBytesToFile

public void writeBytesToFile(byte[] bytes)
                      throws IOException,
RuntimeException

Writes a byte array to a file in the given output.

Note that this could be a destructive operation if there is already a file at that location, so you should take care to perform the necessary verifications.

Parameters:

bytes - a byte[] array with the content to write to the file

Throws:

IOException - if there is an IO error when trying to open the file

RuntimeException - if the write operations have not been enabled at the instance creation