[FELIX-2944] SCR/ spec version 1.1-felix is causing NPE in XmlHandler

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: scr-1.6.0, scr generator 1.1.0
• Fix Version/s: scr-1.6.2, scr generator 1.1.2
• Component/s: Declarative Services (SCR), SCR Tooling
• Assignee: Felix Meschberger
• Reporter: Pierre De Rop
• Created: 05/May/11 14:14
• Updated: 20/Nov/12 10:58
• Resolved: 31/May/11 13:56

Description

This issue is described in the following post: http://www.mail-archive.com/[e-mail]/msg10138.html
and might also be related in the FELIX-1898 issue.

When using SCR (trunk) and the new Reference "updated" callback, we have to specify the spec version "1.1-felix".
However, when using such version, we get the following NPE at runtime: (latest scrplugin has been used to generate the scr xml descriptor):

java.lang.NullPointerException
at org.apache.felix.scr.impl.metadata.XmlHandler.startElement(XmlHandler.java:237)
at org.apache.felix.scr.impl.parser.KXml2SAXParser.parseXML(KXml2SAXParser.java:73)
at org.apache.felix.scr.impl.BundleComponentActivator.loadDescriptor(BundleComponentActivator.java:227)
at org.apache.felix.scr.impl.BundleComponentActivator.initialize(BundleComponentActivator.java:147)
at org.apache.felix.scr.impl.BundleComponentActivator.<init>(BundleComponentActivator.java:111)
at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:274)
at org.apache.felix.scr.impl.Activator.bundleChanged(Activator.java:192)
at org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:807)
at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:729)
at org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:610)
at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:3833)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1803)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1179)
at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:264)
at java.lang.Thread.run(Thread.java:662)

Notice that this exception is displayed on stdout, and it would be probably better to log it using the log service;
From log service, we then get the following exception:

.scr.impl.parser.ParseException: Exception during parsing
at org.apache.felix.scr.impl.metadata.XmlHandler.startElement(XmlHandler.java:333)
at org.apache.felix.scr.impl.parser.KXml2SAXParser.parseXML(KXml2SAXParser.java:73)
at org.apache.felix.scr.impl.BundleComponentActivator.loadDescriptor(BundleComponentActivator.java:227)
at org.apache.felix.scr.impl.BundleComponentActivator.initialize(BundleComponentActivator.java:147)
at org.apache.felix.scr.impl.BundleComponentActivator.<init>(BundleComponentActivator.java:111)
at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:274)
at org.apache.felix.scr.impl.Activator.bundleChanged(Activator.java:192)
at org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:807)
at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:729)
at org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:610)
at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:3833)
at org.apache.felix.framework.Felix.startBundle(Felix.java:1803)
at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1179)
at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:264)
at java.lang.Thread.run(Thread.java:662)

I think that the root cause of the problem is that the scrplugin is generating the following xml namespace:

http://www.osgi.org/xmlns/scr/v1.1.0-felix

but the scr runtime is expecting the following namespace:

http://felix.apache.org/xmlns/scr/v1.1.0-felix

so, there is a mismatch here.
The following patch seems to work and consists in fixing the class XmlHandler.java, in the SCR:
The XmlHandler.NAMESPACE_URI_1_1_FELIX constant can be changed with the following scheme (which must match the one generated by the scrplugin):

public static final String NAMESPACE_URI_1_1_FELIX = "http://www.osgi.org/xmlns/scr/v1.1.0-felix";

Or another option is to fix the scrplugin in order to use the felix.apache.org scheme ?