Routing error cannot load Java class

Hello,
I’m upgrading my application running on Jruby 1.4 & rails 2.3
to Rails 3.1.0 and jruby 1.6. I followed the Rails 3 upgrade Handbook by
Jeremy, and using the plugin rails_upgrade, but when I fire the server
I’m getting errors. like

Routing Error
cannot load Java class com.mysentry.persistence.HibernateUtil

Somebody please help me. This is the error log

Started GET “/admin/login/en/sentry” for 127.0.0.1 at Wed Sep 28
13:13:56 -0400
2011

ActionController::RoutingError (cannot load Java class
com.mysentry.persistence.
HibernateUtil):
org/jruby/javasupport/JavaClass.java:1204:in for_name' org/jruby/javasupport/JavaUtilities.java:34:inget_proxy_class’
C:/upgrade/jruby-1.6.4/lib/ruby/site_ruby/shared/builtin/javasupport/core_ext/
object.rb:46:in java_import' C:/upgrade/jruby-1.6.4/lib/ruby/site_ruby/shared/builtin/javasupport/core_ext/ object.rb:26:ininclude_class’
lib/sentry/interceptor/transaction_interceptor.rb:5:in Interceptor' lib/sentry/interceptor/transaction_interceptor.rb:2:inSentry’
lib/sentry/interceptor/transaction_interceptor.rb:1:in (root)' org/jruby/RubyKernel.java:1038:inrequire’
polyglot (0.3.2) lib/polyglot.rb:63:in require' activesupport (3.1.0) lib/active_support/dependencies.rb:240:inrequire’
activesupport (3.1.0) lib/active_support/dependencies.rb:223:in
load_dependen cy' activesupport (3.1.0) lib/active_support/dependencies.rb:640:innew_constants
_in’
activesupport (3.1.0) lib/active_support/dependencies.rb:639:in
new_constants _in' activesupport (3.1.0) lib/active_support/dependencies.rb:223:inload_dependen
cy’
activesupport (3.1.0) lib/active_support/dependencies.rb:240:in
require' lib/sentry/interceptor/transaction_interceptor.rb:7:inDispatcher’
lib/sentry/dispatcher/application_dispatcher.rb:3:in Sentry' lib/sentry/dispatcher/application_dispatcher.rb:2:in(root)’
org/jruby/RubyKernel.java:1038:in require' polyglot (0.3.2) lib/polyglot.rb:63:inrequire’