Will launch in Eclipse, won't launch from command prompt

Question

I've got a project that works in Eclipse, but won't run from the command line prompt.
The command line command that I'm using is this...
java -cp /users/shared/RainfallSeriesTranslator/bin ui/LauncherThe error I get is this...
Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException
     at ui.Launcher.getMethods(Launcher.java:37)
     at ui.Launcher.<clinit>(Launcher.java:15)and the class is this...
import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
public class Launcher {
     private final static String name = "RainfallSeriesTranslatorPanel";
     private final static String[] methods = getMethods();
     private final static String fileExt = ".class";
     public static void main(String[] args) {
          new Panel(name, methods);
     public static String[] getMethods() {
          String workingDirectory = System.getProperty("user.dir");
          String fileSeparator = System.getProperty("file.separator");
          String methodDirectory = workingDirectory + fileSeparator + "bin" + fileSeparator + "methods";
          File dir = new File(methodDirectory);
          ArrayList <String> methodsAL = new ArrayList<String>();
          FilenameFilter filter = new FilenameFilter() {
                  public boolean accept(File dir, String name) {
                      return name.endsWith(fileExt);
          String []contents = dir.list(filter);
          for (int i = 0; i < contents.length; i++){
               methodsAL.add(contents.replace(fileExt, ""));
          return methodsAL.toArray(new String[methodsAL.size()]);
     public String getPanelName() {
          return name;
     public String getFileExtensionName() {
          return fileExt;
}BTW the purpose of getMethods is to dynamically list out the classes (files) in the directory 'methods', and to load the names into an array which is passed to a JComboBox in the Panel.  My intention is to permit users to select which method to use for the next step of the analysis.  If there's a better way to do it, I'd like to know.
Having played around with the code, I can get it to run if I 'hardwire' the methodsAL arraylist to ...          methodsAL.add("Some method");...but that defeats the purpose of reading in the classnames dynamically.
So, the nullpointerexception seems to do with the array 'contents' not getting populated, but I can't figure out why.  As I noted above, it works in Eclipse, so why doesn't it work from the command prompt?                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

Martin_J wrote:
Sorry, I had cut out some comment lines at the top.
Line 37 is the line
for (int i = 0; i < contents.length; i++){So it looks like the nullpointerexception is generated because the array 'contents' has a null (zero?) length.
On reflection, is this to do with the working directory? You will note that I have prepended the 'methods' directory with the working directory path. I'm thinking that this would work in Eclipse because the working directory is something, but it does not work when I execute from the command prompt because the working directory is something else.
If this is the case, then what is the best way to find a directory at a relative location to a class?You get that error because the directory doesn't exist at the given location (the bin folder I guess). dir.list() returns null.
Kaj