summaryrefslogtreecommitdiffstats
path: root/src/main/java/org/openslx/imagemaster/util/Util.java
blob: 9e0f70865f9dd127450e6a1b47727507d37d27c2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
package org.openslx.imagemaster.util;

import java.io.File;
import java.util.Random;

import org.apache.log4j.Logger;

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 friendsly 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 );
		}
	}
	
	/**
	 * 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();
	}

}