Custom ClassLoader - fails to load java/lang/Object

Question

I have created a custom class loader based substantially on Jim Farley's code in "Java Distributed Computing" pp 39-44.
The code does get a URL connection, download the class file, but fails when it tries to load (re-load) java/lang/Object. My understanding is that the same (custom) class loader is also used to load dependent classes (needed by the class your are originally loading). I had assumed that this would be handled by the call to findSystemClass() I had assumed.
Any help or direction is appreciated,
Jeff.
Here is the output:
File=/tasks/Person.class
Host=n01
Trying to load:/tasks/Person
Check system :/tasks/Person
Not found in System:/tasks/Person
Check stream:/tasks/Person
Class file is 815 bytes.
Available = 815
RemoteClassLoader: Reading class from stream...
RemoteClassLoader: Defining class...
java.lang.ClassNotFoundException: Cannot find class definition:
java.lang.NoClassDefFoundError: java/lang/Object
     at java.lang.ClassLoader.defineClass0(Native Method)
     at java.lang.ClassLoader.defineClass(ClassLoader.java:486)
     at java.lang.ClassLoader.defineClass(ClassLoader.java:426)
     at RemoteClassLoader.readClass(RemoteClassLoader.java:83)
     at RemoteClassLoader.loadClass(RemoteClassLoader.java:139)
     at TestRemoteClassLoader.main(TestRemoteClassLoader.java:18)
Class was not loaded.Here is the code:
import java.lang.*;
import java.net.*;
import java.io.*;
import java.util.Hashtable;
public class RemoteClassLoader extends ClassLoader {
   URL classURL = null;
   InputStream classStream = null;
   java.lang.Object o = null;
   Hashtable classCache = new Hashtable();
   InputStream source = null;
   // Constructor
   public RemoteClassLoader()
   // Parse a class name from a class locator (URL, filename, etc.)
   protected String parseClassName(String classLoc)
      throws ClassNotFoundException
         String className = null;
         try { classURL = new URL(classLoc); }
         catch (MalformedURLException malex) {
            throw new ClassNotFoundException("Bad URL \"" + classLoc + "\"given: " + malex);
         System.out.println("File=" + classURL.getFile());
         System.out.println("Host=" + classURL.getHost());
         String filename = classURL.getFile();
         // Make sure this is a class file
         if (!filename.endsWith(".class"))
            throw new ClassNotFoundException("Non-class URL given.");
         else
            className = filename.substring(0,filename.lastIndexOf(".class"));
         return className;
   // Initialize the input stream from a class locator
   protected void initStream(String classLoc)
      throws IOException
         classStream = classURL.openStream();
   // Read a class from the input stream
   protected Class readClass(String classLoc, String className)
      throws IOException, ClassNotFoundException
         //See how large the class file is.
         URLConnection conn = classURL.openConnection();
         int classSize = conn.getContentLength();
         System.out.println("Class file is " + classSize + " bytes.");
         // Read the class bytecodes from the stream
         DataInputStream dataIn = new DataInputStream(classStream);
         int avail = dataIn.available();
         System.out.println("Available = " + avail);
         System.out.println("RemoteClassLoader: Reading class from stream...");
         byte[] classData = new byte[classSize];
         dataIn.readFully(classData);
         // Parse the class definition from the bytecodes
         Class c = null;
         System.out.println("RemoteClassLoader: Defining class...");
         try{ c = defineClass(null, classData, 0, classData.length); }
         catch (ClassFormatError cfex) {
            throw new ClassNotFoundException("Format error found in class data.");
         catch (NoClassDefFoundError clsdeferr) {
            clsdeferr.printStackTrace();           
            throw new ClassNotFoundException("Cannot find class definition:\n" + clsdeferr);
         return c;
   // load the class
   public Class loadClass(String classLoc, boolean resolve)
      throws ClassNotFoundException
         String className = parseClassName(classLoc);
         Class c;
         System.out.println("Trying to load:" + className);
         //maybe already loaded
         c = findLoadedClass(className);
         if (c!=null) {
            System.out.println("Already loaded.");
            return c;
         c = (Class) classCache.get(className);
         if (c!=null) {
            System.out.println("Class was loaded from cache...");
            return c;
         System.out.println("Check system :" + className);
         // Not in cache, try the system class...
         try {
            c = findSystemClass(className);
            if (c!=null) {
               System.out.println("System class found...");
               classCache.put(className, c);
               return c;
         catch (ClassNotFoundException cnfex) {
            System.out.println("Not found in System:" + className);
            ; // keep looking
         System.out.println("Check stream:" + className);
         // Not in system either, so try to get from tthe stream
         try {initStream(classLoc); }
         catch (IOException ioe) {
            throw new ClassNotFoundException("Failed opening stream to URL.");
         // Read the class from the input stream
         try {c = readClass(classLoc, className); }
         catch (IOException ioe) {
               throw new ClassNotFoundException("Failed reading class from stream: " + ioe);
         // Add the new class to the cache for the next reference.
         classCache.put(className, c);
         // Resovle the class, if requested
         if (resolve)
            resolveClass(c);
         return c;

Answer 1

Never mind - I've figure it out.
The problem is that the ClassLoader calls RemoteClassLoader.loadClass() to load in java.lang.Object, which is fine. But, my code tries to first create a URL from this, which fails, eventually throwing a NoClassDefFoundError.
I have fixed it by delaying the call to parseName() until after checking loaded classes and system classes.