As part of overall NETVIRT-719 (but also in SFC-196), see full log attached there, this NPE from openflowjava appears in Karaf 4 (only) based distributions:

2017-06-08 15:52:23,726 | ERROR | rint Extender: 2 | Futures$CombinedFuture | 71 - com.google.guava - 18.0.0 | input future failed.
java.lang.NullPointerException
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.createAndConfigureServer(SwitchConnectionProviderImpl.java:145)
at org.opendaylight.openflowjava.protocol.impl.core.SwitchConnectionProviderImpl.startup(SwitchConnectionProviderImpl.java:112)
at Proxy36c334b0_0d6d_4985_afe8_4592d2045c49.startup(Unknown Source)
at Proxyd08be1e6_bbbf_4f92_ab69_c11c5fcc6a45.startup(Unknown Source)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.lambda$startSwitchConnections$0(OpenFlowPluginProviderImpl.java:150)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)[:1.8.0_131]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)[:1.8.0_131]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)[:1.8.0_131]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)[:1.8.0_131]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)[:1.8.0_131]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)[:1.8.0_131]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)[:1.8.0_131]
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.startSwitchConnections(OpenFlowPluginProviderImpl.java:151)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderImpl.initialize(OpenFlowPluginProviderImpl.java:232)
at org.opendaylight.openflowplugin.impl.OpenFlowPluginProviderFactoryImpl.newInstance(OpenFlowPluginProviderFactoryImpl.java:106)