[DOSGI-178] NullPointerException when interface method declares throwing custom exception

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.0, 1.5.0
• Fix Version/s: 2.0.0

Environment

Oracle JDK 1.7.0_17, DOSGi 1.4.0/1.5.0, Karaf 2.3.1 (Aegis Databinding 2.7.2)

• Estimated Complexity: Unknown
• Assignee: Christian Schneider
• Reporter: Amichai Rothman
• Created: 23/Apr/13 23:25
• Updated: 24/Mar/17 09:05
• Resolved: 24/Mar/17 09:05

Description

I'm getting an Aegis exception (stacktrace below) when trying to export a service. It looks similar to CXF-3613, but that is closed as fixed in 2.7.1. I also found mention of it in http://mail-archives.apache.org/mod_mbox/cxf-dev/201301.mbox/[e-mail]%3E from a few months ago but nothing further.

I tried debugging a bit, and it seems to fail when the service interface has a method declaring a throws clause with a custom exception which is a trivial Exception subclass (with no fields, just standard constructors). Somewhere down the line of dependencies it reaches a java.lang.Class, which has a field of type T[] named enumConstants, it tries to get the base type for component type "T", which returns null, which causes the exception.

Update: I think I found a temporary workaround: I changed the custom exception to extend RuntimeException instead of Exception, and changed the interface to declare throwing RuntimeException instead of the custom exception, and now I no longer see this exception occurring. The reason for using RuntimeException (rather than Exception) is so that the rest of the code does not require any modification - only the exception class and the interface are changed, and only those will need to be reverted when a proper fix is released.

However, it's still bad that code needs to be changed in order for DOSGi to work (one of its main selling points is transparency to OSGi services), plus the code loses compile-time exception checking for users of the interface/service.

java.lang.NullPointerException
at java.lang.reflect.Array.newArray(Native Method)[:1.7.0_17]
at java.lang.reflect.Array.newInstance(Array.java:70)[:1.7.0_17]
at org.apache.cxf.aegis.type.TypeUtil.getTypeRelatedClass(TypeUtil.java:261)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.type.AbstractTypeCreator.createTypeForClass(AbstractTypeCreator.java:108)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.type.AbstractTypeCreator.createType(AbstractTypeCreator.java:402)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.type.basic.BeanTypeInfo.getType(BeanTypeInfo.java:192)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.type.basic.BeanType.getDependencies(BeanType.java:534)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.addDependencies(AegisDatabinding.java:394)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.addDependencies(AegisDatabinding.java:399)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.addDependencies(AegisDatabinding.java:399)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.initializeMessage(AegisDatabinding.java:371)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.initializeOperation(AegisDatabinding.java:283)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.aegis.databinding.AegisDatabinding.initialize(AegisDatabinding.java:242)[178:org.apache.cxf.cxf-rt-databinding-aegis:2.7.2]
at org.apache.cxf.service.factory.AbstractServiceFactoryBean.initializeDataBindings(AbstractServiceFactoryBean.java:86)[165:org.apache.cxf.cxf-rt-core:2.7.2]
at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.buildServiceFromClass(ReflectionServiceFactoryBean.java:475)[165:org.apache.cxf.cxf-rt-core:2.7.2]
at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.initializeServiceModel(ReflectionServiceFactoryBean.java:537)[165:org.apache.cxf.cxf-rt-core:2.7.2]
at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.create(ReflectionServiceFactoryBean.java:249)[165:org.apache.cxf.cxf-rt-core:2.7.2]
at org.apache.cxf.frontend.AbstractWSDLBasedEndpointFactory.createEndpoint(AbstractWSDLBasedEndpointFactory.java:101)[172:org.apache.cxf.cxf-rt-frontend-simple:2.7.2]
at org.apache.cxf.frontend.ServerFactoryBean.create(ServerFactoryBean.java:159)[172:org.apache.cxf.cxf-rt-frontend-simple:2.7.2]
at org.apache.cxf.dosgi.dsw.handlers.AbstractPojoConfigurationTypeHandler.createServerFromFactory(AbstractPojoConfigurationTypeHandler.java:208)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.dsw.handlers.PojoConfigurationTypeHandler.createServer(PojoConfigurationTypeHandler.java:118)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminCore.exportService(RemoteServiceAdminCore.java:119)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminInstance$1.run(RemoteServiceAdminInstance.java:64)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminInstance$1.run(RemoteServiceAdminInstance.java:58)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at java.security.AccessController.doPrivileged(Native Method)[:1.7.0_17]
at org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminInstance.exportService(RemoteServiceAdminInstance.java:58)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.dsw.service.RemoteServiceAdminInstance.exportService(RemoteServiceAdminInstance.java:37)[56:cxf-dosgi-ri-dsw-cxf:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.topologymanager.exporter.TopologyManagerExport.doExportService(TopologyManagerExport.java:249)[72:cxf-dosgi-ri-topology-manager:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.topologymanager.exporter.TopologyManagerExport.access$300(TopologyManagerExport.java:50)[72:cxf-dosgi-ri-topology-manager:1.5.0.SNAPSHOT]
at org.apache.cxf.dosgi.topologymanager.exporter.TopologyManagerExport$3.run(TopologyManagerExport.java:214)[72:cxf-dosgi-ri-topology-manager:1.5.0.SNAPSHOT]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)[:1.7.0_17]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)[:1.7.0_17]
at java.lang.Thread.run(Thread.java:722)[:1.7.0_17]