implement jar and file URL stream handlers

classpath/java/net/JarURLConnection.java

@@ -0,0 +1,22 @@
+/* Copyright (c) 2011, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+package java.net;
+
+import java.io.IOException;
+import java.util.jar.JarFile;
+
+public abstract class JarURLConnection extends URLConnection {
+  public JarURLConnection(URL url) {
+    super(url);
+  }
+
+  public abstract JarFile getJarFile() throws IOException;
+}