# Can't Marshal.dump a Java object (from using Rjb) **URL:** \ **Category:** Ruby\ **Created:** [March 7, 2007, 7:13pm UTC](https://www.ruby-forum.com/t/cant-marshal-dump-a-java-object-from-using-rjb/88048 "2007-03-07T19:13:28Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![weyus](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/7ab992/32.png) [@weyus](https://www.ruby-forum.com/u/weyus)\ **Post date:** [March 7, 2007, 7:13pm UTC](https://www.ruby-forum.com/t/cant-marshal-dump-a-java-object-from-using-rjb/88048/1 "2007-03-07T19:13:28Z")
All, I have a Ruby object that actually encapsulates a Java object - I got it by using Rjb to talk to a Java library. When I attempt to marshal it, I get the following error: “can’t dump anonymous class” If Rjb returned a named class instead of an anonymous one, would I then be able to marshal it? BTW, why can’t anonymous classes be dumped? Thanks, Wes ---
**Author:** ![weyus](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/7ab992/32.png) [@weyus](https://www.ruby-forum.com/u/weyus)\ **Post date:** [March 7, 2007, 10:05pm UTC](https://www.ruby-forum.com/t/cant-marshal-dump-a-java-object-from-using-rjb/88048/2 "2007-03-07T22:05:00Z")
On Thu, 8 Mar 2007 03:13:33 +0900, Wes G. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > If Rjb returned a named class instead of an anonymous one, would I then > be able to marshal it? No, not at this time. It isn’t even technically feasible to implement unless the Java object being wrapped belongs to a class which supports Java serialization (i.e. implements java.io.Serializable). > BTW, why can’t anonymous classes be dumped? A class name is required by Ruby’s marshal format, since otherwise there would be no way to determine which class to use when loading the marshalled object. Remember that a dumped object may be loaded in a different interpreter instance than the one that dumped it. -mental