Image loading troubles

[Palocles]

I’m working from Killer Game Programming and trying to modify the code so that i can use it in my project, which is still in early development. i’m using Netbeans.

I’ve got this bunch of errors:

run:
Reading file: images\BoganImagesLoader.txt
Exception in thread “main” java.lang.NullPointerException
at java.io.Reader.(Reader.java:78)
at java.io.InputStreamReader.(InputStreamReader.java:72)
at barbarplatform.ImagesLoader.loadImagesFile(ImagesLoader.java:55)
at barbarplatform.ImagesLoader.(ImagesLoader.java:35)
at barbarplatform.GamePanel.(GamePanel.java:90)
at barbarplatform.BarbarPlatform.main(BarbarPlatform.java:29)
Java Result: 1
BUILD SUCCESSFUL (total time: 1 second)

Which i think are related to the location of my images folder.

Code snippet where the first two errors are coming from:

public class ImagesLoader {
    private final static String IMAGE_DIR = "images/";
    
    private HashMap imagesMap;
        /* The key is the filename prefix, the object (value) 
       is an ArrayList of BufferedImages */
    private HashMap gNamesMap;
        /* The key is the 'g' <name> string, the object is an
       ArrayList of filename prefixes for the group. This is used to 
       access a group image by its 'g' name and filename. */
    
    private GraphicsConfiguration gc;
    
    public ImagesLoader(String fnm){
        //begin by loading images specified in fnm
        initLoader();
        loadImagesFile(fnm);          //line 35 here
    }       //end of ImagesLoader()
    
    public ImagesLoader(){
        initLoader();
    }
    
    private void initLoader(){
        imagesMap = new HashMap();
        gNamesMap = new HashMap();
        
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        gc = ge.getDefaultScreenDevice().getDefaultConfiguration();
    }       //end of initLoader()
    
    private void loadImagesFile(String fnm){
        String imsFNm = IMAGE_DIR + fnm;
        System.out.println("Reading file: " + imsFNm);
        try{
            InputStream in = this.getClass().getResourceAsStream(imsFNm);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));    //line 55 here
            String line;
            char ch;
            while ((line = br.readLine()) != null){
                if(line.length() == 0)          //blank line
                    continue;
                else if(line.startsWith("//"))  //comment
                    continue;
                ch = Character.toLowerCase(line.charAt(0));
                if(ch == 'o')       //a single image
                    getFileNameImage(line);
//                else if(ch == 'n')  //a numbered sequence of images
//                    getNumberedImages(line);
                else if(ch == 's')  //an images strip
                    getStripImages(line);
//                else if (ch == 'g') //a group of images
//                    getGroupImages(line);
                else
                    System.out.println("Do not recognize line " + line);
            }
            br.close();
        }catch (IOException ioe){
            System.out.println("Error reading file: " + imsFNm + ioe);
            System.exit(1);
        }
    }       //end of loadImagesFile

Any ideas from this? I can post more stuff and try a few things if there are any suggestions.

Thanks.