java_gen: add accessor to reader to offactory
diff --git a/java_gen/templates/of_factory_interface.java b/java_gen/templates/of_factory_interface.java
index 467504e..39432a8 100644
--- a/java_gen/templates/of_factory_interface.java
+++ b/java_gen/templates/of_factory_interface.java
@@ -42,4 +42,6 @@
     //:: #endif
     ${i.name}.Builder create${i.name[2:]}Builder()${ "" if i.is_universal else " throws UnsupportedOperationException"};
 //:: #endfor
+
+    OFMessageReader<OFMessage> getMessageReader();
 }