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package org.openslx.imagemaster.util;
import java.io.File;
import java.util.Random;
import org.apache.log4j.Logger;
/**
* Some utilities to make our lives easier.
*/
public class Util
{
private static Logger log = Logger.getLogger( Util.class );
/**
* Check if the given object is null, abort program if true.
* An optional message to be printed can be passed. A stack trace
* will be printed, too. Finally the application terminates with
* exit code 2.
*
* This comes in handy if something must not be null, and you want
* user friendly output. A perfect example would be reading settings
* from a config file. You can use this on mandatory fields.
*
* @param something the object to compare to null
* @param message the message to be printed if something is null
*/
public static void notNullFatal( Object something, String message )
{
if ( something == null ) {
if ( message != null )
log.fatal( "[NOTNULL] " + message );
log.warn( Thread.currentThread().getStackTrace().toString() );
System.exit( 2 );
}
}
/**
* Check if String is null or empty, abort program if so.
* An optional message to be printed can be passed. A stack trace
* will be printed, too. Finally the application terminates with
* exit code 2.
*
* @param something The string you want to check
* @param message The message to be printed if "something" is null or empty
*/
public static void notNullOrEmptyFatal( String something, String message )
{
if ( something == null || something.isEmpty() ) {
if ( message != null )
log.fatal( "[NOTNULL] " + message );
log.warn( Thread.currentThread().getStackTrace().toString() );
System.exit( 2 );
}
}
/**
* Static {@link Random} instance.
*/
private static final Random random = new Random();
/**
* Return a random integer in the range of 0 (inclusive) and
* n (exclusive). Uses the internal static instance of {@link Random},
* so you don't have to deal with instances everywhere.
*
* @param n the upper bound (exclusive)
* @return number between 0 (inclusive) and n (exclusive)
*/
public static int randomInt( int n )
{
return random.nextInt( n );
}
/**
* Remove a folder and all contents
*
* @param folder
*/
public static void deleteFolder( File folder )
{
File[] files = folder.listFiles();
if ( files != null ) {
for ( File f : files ) {
if ( f.isDirectory() ) {
deleteFolder( f );
} else {
f.delete();
}
}
}
folder.delete();
}
/**
* Tries to parse an int. Returns 0 on error.
*
* @param s The strig to parse
* @return The parsed int or 0 on error
*/
public static int tryToParseInt( String s )
{
return tryToParseInt( s, 0 );
}
/**
* Tries to parse an int. Returns defaultValue on error.
*
* @param s The strig to parse
* @param defaultValue value to be returned if s is not parsable
* @return The parsed int
*/
public static int tryToParseInt( String s, int defaultValue )
{
try {
return Integer.parseInt( s );
} catch ( NumberFormatException e ) {
return defaultValue;
}
}
public static int getNumberOfBlocks( long fileSize, int blockSize )
{
int blocks = (int) ( fileSize / blockSize );
if ( fileSize % blockSize != 0 )
blocks++;
return blocks;
}
public static String sanitizeFileName( String fileName )
{
fileName = fileName.replaceAll( "[^a-zA-Z0-9_\\-]+", "_" );
if ( fileName.length() > 40 )
fileName = fileName.substring( 0, 40 );
return fileName;
}
}
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