Re: [cp-patches] RFC: New system class loader implementation

[Archie Cobbs]

Jeroen Frijters wrote:
> I would like to move my implementation of the System class loader into
> Classpath. I've been running with this implementation (minus the new
> checkPackageAccess) for a while and it seems to work very well. The
> current version in Classpath is known to be broken and I don't think
> anybody uses it.
> 
> Not included in the patch, but this removes the need for
> gnu/java/lang/SystemClassLoader.java.
> 
> The hook in VMClassLoader continues to exist, for those that want to
> implement the system class loader in another way.

Looks good.

I'd also like to add this patch which I've been using.. though I'm a
bit suspicious of why the exising code has the comment "this requires
native help"... it doesn't seem to me that native help is required,
at least for non-specialized VMs.

-Archie

__________________________________________________________________________
Archie Cobbs      *        CTO, Awarix        *      http://www.awarix.com

--- /home/archie/classpath/cvs/vm/reference/java/lang/VMClassLoader.java        
Mon Oct 11 11:03:25 2004
+++ /home/archie/xx     Mon Oct 11 11:11:02 2004
@@ -40,10 +40,14 @@
 
 import java.security.ProtectionDomain;
 import java.net.URL;
+import java.io.File;
 import java.io.IOException;
+import java.net.MalformedURLException;
 import java.util.Enumeration;
 import java.util.Map;
 import java.util.HashMap;
+import java.util.StringTokenizer;
+import java.util.Vector;
 import java.lang.reflect.Constructor;
 import gnu.java.lang.SystemClassLoader;
 
@@ -136,28 +140,44 @@
   /**
    * Helper to load a resource from the bootstrap class loader.
    *
-   * XXX - Not implemented; this requires native help.
-   *
    * @param name the resource to find
    * @return the URL to the resource
    */
   static URL getResource(String name)
   {
+    Enumeration e = getResources(name);
+    if (e.hasMoreElements())
+      return (URL)e.nextElement();
     return null;
   }
 
   /**
    * Helper to get a list of resources from the bootstrap class loader.
    *
-   * XXX - Not implemented; this requires native help.
-   *
    * @param name the resource to find
    * @return an enumeration of resources
    * @throws IOException if one occurs
    */
-  static Enumeration getResources(String name) throws IOException
+  static Enumeration getResources(String name)
   {
-    return EmptyEnumeration.getInstance();
+    StringTokenizer st = new StringTokenizer(
+      System.getProperty("java.boot.class.path", "."), File.pathSeparator);
+    Vector v = new Vector();
+    while (st.hasMoreTokens())
+      {
+       File file = new File(st.nextToken(), name);
+       if (!file.exists())
+         continue;
+       try
+         {
+           v.add(new URL("file://" + file.getAbsolutePath()));
+         }
+       catch (MalformedURLException e)
+         {
+           throw new Error(e);
+         }
+      }
+    return v.elements();
   }
 
   /**