--- java/org/apache/tomcat/util/digester/ObjectCreateRule.java	(revision 1516628)
+++ java/org/apache/tomcat/util/digester/ObjectCreateRule.java	(working copy)
@@ -19,6 +19,10 @@ 
 package org.apache.tomcat.util.digester;
 
 
+import java.net.URL;
+import java.net.URLClassLoader;
+
+import org.apache.juli.logging.Log;
 import org.xml.sax.Attributes;
 
 
@@ -141,11 +145,50 @@ 
         }
 
         // Instantiate the new object and push it on the context stack
-        Class<?> clazz = digester.getClassLoader().loadClass(realClassName);
-        Object instance = clazz.newInstance();
-        digester.push(instance);
+        ClassLoader classLoader = digester.getClassLoader();
+        try {
+            Class<?> clazz = classLoader.loadClass(realClassName);
+            Object instance = clazz.newInstance();
+            digester.push(instance);
+        } catch (ClassNotFoundException t) {
+            Log log = digester.log;
+            log.warn(t.getMessage(), t);
+            showClassPath(classLoader, 0, log);
+            throw t;
+        }
     }
 
+    public static void showClassPath(ClassLoader classLoader,
+            int antiRecursion, Log log) {
+        StringBuffer extraInfo = new StringBuffer("ClassLoader " + classLoader
+                + "\n");
+        if (classLoader instanceof URLClassLoader) {
+            URLClassLoader ucl = (URLClassLoader) classLoader;
+            URL[] urls = ucl.getURLs();
+            if (null == urls || 0 == urls.length) {
+                extraInfo.append("null == urls");
+            } else {
+                int i = 0;
+                for (i = 0; i < urls.length; i++) {
+                    URL url = urls[i];
+                    extraInfo.append(url.toString()).append(",\n");
+                }
+                log.warn(extraInfo);
+            }
+            ClassLoader parent = ucl.getParent();
+            if (null != parent) {
+                if (!parent.equals(ucl)) {
+                    if (7 < antiRecursion) {
+                        log.error("too many recursions");
+                    } else {
+                        antiRecursion++;
+                        log.warn("\nParent " + antiRecursion + ":");
+                        showClassPath(parent, antiRecursion, log);
+                    }
+                }
+            }
+        }
+    }
 
     /**
      * Process the end of this element.
--- java/org/apache/catalina/loader/WebappClassLoader.java	(revision 1516628)
+++ java/org/apache/catalina/loader/WebappClassLoader.java	(working copy)
@@ -77,6 +77,7 @@ 
 import org.apache.naming.resources.ResourceAttributes;
 import org.apache.tomcat.util.ExceptionUtils;
 import org.apache.tomcat.util.IntrospectionUtils;
+import org.apache.tomcat.util.digester.ObjectCreateRule;
 import org.apache.tomcat.util.res.StringManager;
 
 /**
@@ -1711,7 +1712,9 @@ 
             }
         }
 
-        throw new ClassNotFoundException(name);
+        ClassNotFoundException classNotFoundException = new ClassNotFoundException(name);
+        ObjectCreateRule.showClassPath(this, 0, log);
+		throw classNotFoundException;
 
     }