Class loader - ClassFormatError

Question

Hey guys,
I have a problem with my loading a class file, I get this error:
Exception in thread "AWT-EventQueue-0" java.lang.ClassFormatError: Code segment has wrong length in class file j2MeDataChunkGenerator_Plugin/DataChunkGenerator.class
I know I compiled it right, since other classes does load, I didn't try to manipulate the byte code or any thing like this, could anything code related might generate this kind of exception??
in the beginning I thought this was an error with my class loading process, but once I recreated an empty duplicate of the problem, it works fine, and all the classes are been loaded correctly.
Any help or idea would be greatly appreciated, I've been at it for 4 evenings ;..(
Thanks in advance,
Adam.

Answer 1

I should have put this earlier:
the class loading method:
     public static class PluginClassLoader extends ClassLoader {
          // public PluginClassLoader() {
          // super(new URL[] {});
          private ArrayList<JarFile> jars = new ArrayList<JarFile>();
          public synchronized void add(JarFile jar) throws MalformedURLException {
               jars.add(jar);
          public Class<?> loadClass(String className) throws ClassNotFoundException {
               try {
                    try {
                         System.out.println("Looking in super.loadClass(className=" + className + ")");
                         Class<?> _class=super.loadClass(className);
                         System.out.println("Class was found: "+className);
                         return _class;
                         // return checkIfClassWasLoaded(className, false);
                    } catch (ClassNotFoundException e1) {
                         System.out.println("Class was not found: "+className);
                         System.out.println("Looking in the Jar files for className=" + className);
                         for (int i = 0; i < jars.size(); i++) {
                              JarFile jar = jars.get(i);
                              Enumeration<JarEntry> enumeration = jar.entries();
                              while (enumeration.hasMoreElements()) {
                                   java.util.jar.JarEntry file = (JarEntry) enumeration.nextElement();
                                   if (file.getName().equals(className.replace(".", "/") + ".class")) {
                                        System.out.println("A match to " + className + " was found in: \n" + jar.getName().replace("\\", "/") + "!/" + file.getName()+"\n");
                                        InputStream is = jar.getInputStream(file);
                                        byte[] bytes;
                                        int length = is.available();
                                        bytes = new byte[length];
                                        is.read(bytes);
                                        return defineClass(className, bytes, 0, bytes.length);
               } catch (IOException e) {
                    System.out.println("Unable to locate class file: " + className);
                    e.printStackTrace();
               throw new ClassNotFoundException(className);
          private Class<?> checkIfClassWasLoaded(String className, boolean pResolve) throws ClassNotFoundException {
               System.out.println("checkIfClassWasLoaded(" + className + ", " + pResolve + ")");
               Class<?> lClass = findLoadedClass(className);
               if (lClass == null) {
                    try {
                         ClassLoader lParent = getParent();
                         if (lParent == null) {
                              lClass = getSystemClassLoader().loadClass(className);
                         } else {
                              lClass = lParent.loadClass(className);
                    } catch (ClassNotFoundException cnfe) {
                         lClass = findSystemClass(className);
               try {
                    if (pResolve) {
                         System.out.println("resolve class: " + lClass);
                         resolveClass(lClass);
               } catch (Error e) {
                    e.printStackTrace();
                    throw e;
               return lClass;
           * checks if this plugin .jar file was loaded already into this class
           * loader jar list.
           * @param file
           *            - the file of the plugin jar
           * @return
           * @throws IOException
          public JarFile contains(String jarPath) {
               for (JarFile file : jars)
                    if (file.getName().equalsIgnoreCase(jarPath))
                         return file;
               return null;
     }