[VELOCITY-870] Exception displayed when trying to loop over an Iterable private class

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.7
• Fix Version/s: 1.7.x, 1.x, 2.0
• Component/s: Engine
• Assignee: Sergiu Dumitriu
• Reporter: Vincent Massol
• Created: 04/Dec/15 12:43
• Updated: 07/Nov/16 09:13
• Resolved: 04/Dec/15 21:43

Description

Specifically I got the following failure (see also https://java.net/jira/browse/TRUEVFS-158):

...
Caused by: java.lang.IllegalAccessException: Class org.apache.velocity.util.introspection.UberspectImpl can not access a member of class net.java.truevfs.access.TFileSystem$Stream with modifiers "public"
at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:109)
at java.lang.reflect.AccessibleObject.slowCheckMemberAccess(AccessibleObject.java:261)
at java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:253)
at java.lang.reflect.Method.invoke(Method.java:599)
at org.apache.velocity.util.introspection.UberspectImpl.getIterator(UberspectImpl.java:158)

The problem as I understand it is that TrueVFS returns a private class and Velocity shouldn't try to call iterator() on it since it's private.

Right now the UberspectImpl code does this:

            Class type = obj.getClass();
            try
            {
                Method iter = type.getMethod("iterator", null);
                Class returns = iter.getReturnType();
                if (Iterator.class.isAssignableFrom(returns))
                {
                    try
                    {
                        return (Iterator)iter.invoke(obj, null);
...

Instead, it could continue to do this but if the method is private then it could also fallback to something like the following:

Class type = Iterable.class;
if (obj instanceof Iterable) {
  Method iter = type.getMethod("iterator", null);
  return (Iterator) iter.invoke(obj, null);
}

Issue Links

• is related to: VELOCITY-871 #foreach should work over any Iterable class