Failing to load rome.properties

[PatrickGotthard]

=== This issue was migrated from JIRA ===
Type: Bug
Priority: Major
Status: Open
Resolution: UNRESOLVED
Reported by: buckett
Assigned to: ROME Jira Lead
Created: Mon Apr 20 10:47:11 CEST 2009
Updated: Thu Sep 15 20:55:38 CEST 2011
Resolved: Mon Apr 20 13:29:19 CEST 2009
Version: current
Fix version: milestone 1
JIRA Link: https://rometools.jira.com/browse/ROME-129
=========================================

Currently we use an old version of rome, rome-fetcher in Sakai
(http://sakaiproject.org) and I was looking as upgrading them to the latest
version to them. Currently Sakai has complicated classloader setup. There is a
description of it here.

https://source.sakaiproject.org/svn/reference/trunk/docs/architecture/sakai_component.doc

Sakai runs ontop of tomcat and each "component" has it's own classloader that
child of the shared classloader. The API for the component goes in shared so
that both the component and any webapp can access. The component then implements
this APi. But the implementation code can't be accessed by the webapp as the
component's classloader isn't a parent of the webapps. This prevents any webapps
accessing anything in a component.

Currently there is an API for getting RSS feeds which is implemented by a
component containing rome. The problem is that when a webapp calls through to
this component the thread classloader is still set to the webapp's so it
attempts to load the master configuration file (rome.properties) from the
webapp. This fails and causes rome to stop working.

It would be useful if PropertiesLoader could use either the thread classloader
or the classloader that loaded PropertiesLoader to load the configuration.

[PatrickGotthard]

=== This comment was migrated from JIRA ===
Author: buckett
Created: Mon Apr 20 13:27:45 CEST 2009
===========================================

Created an attachment (id=34)
A patch that makes the classloader rome uses configurable

[PatrickGotthard]

=== This comment was migrated from JIRA ===
Author: buckett
Created: Mon Apr 20 13:29:19 CEST 2009
===========================================

The attached patch fixes rome so it works in Sakai. It allows the classloader to
be configured through the system property:

rome.use.thread.classloader

It defaults to false which is a change in behaviour from the current version of
rome.

[PatrickGotthard]

=== This comment was migrated from JIRA ===
Author: anonymous
Created: Thu Sep 15 20:55:38 CEST 2011
===========================================

Attachment rome-129.patch has been added with description: rome-129.patch

[lewismc]

Is anyone thinking about testing this patch out?

[sebastian-nagel]

This problem is also hit by Apache Nutch (cf. NUTCH-1494 and NUTCH-1893): various documents formats (including feeds) are parsed by plugins, every plugin has its own class loader. The problem is currently worked around by downgrading to rome 0.9.

[buckett]

Is there anything that needs doing to get this fix into rome? If I created a pull request would that help?

[mishako]

@lewismc @sebastian-nagel @buckett This seems to have been fixed since Rome 1.5.0, i.e. calls to Thread.currentThread().getContextClassLoader() have been removed in https://github.com/rometools/rome/commit/6029420e5f7eea32cecd3cf6c504459da0bc8d77. The class loader used in Rome now is the one that loaded Rome classes and has access to rome.properties.

However you might have problems using Rome in OSGi environment because it's not being packaged as an OSGi bundle. This will be addressed in OSGi-related issues like #143 and #135.

[sebastian-nagel]

@mishako @lewismc I can confirm that the problem is fixed when Rome 1.5.1 is used (I didn't test 1.5.0). We are going to upgrade the Rome library dependency, see NUTCH-2193. Thanks!