ATLAS-2134: Code Improvements.

repository/src/main/java/org/apache/atlas/repository/impexp/ZipSource.java

@@ -175,7 +175,7 @@ public class ZipSource implements EntityImportStream {
             currentPosition++;
             return getEntityWithExtInfo(this.iterator.next());
         } catch (AtlasBaseException e) {
-            e.printStackTrace();
+            LOG.error("getNextEntityWithExtInfo", e);
             return null;
         }
     }

repository/src/main/scala/org/apache/atlas/query/GraphPersistenceStrategies.scala

@@ -284,6 +284,8 @@ case class GraphPersistenceStrategy1(g: AtlasGraph[_,_]) extends GraphPersistenc
             case DataTypes.TypeCategory.TRAIT =>
                 throw new UnsupportedOperationException(s"load for ${aInfo.dataType()} not supported")
             case DataTypes.TypeCategory.CLASS => loadStructAttribute(dataType, aInfo, i, v)
+            case DataTypes.TypeCategory.RELATIONSHIP =>
+                throw new UnsupportedOperationException(s"load for ${aInfo.dataType()} not supported")
         }
     }
 

repository/src/main/scala/org/apache/atlas/query/QueryParser.scala

@@ -233,6 +233,7 @@ object QueryParser extends StandardTokenParsers with QueryKeywords with Expressi
     def querySrc: Parser[Expression] = rep1sep(singleQrySrc, opt(COMMA)) ^^ { l => l match {
         case h :: Nil => h
         case h :: t => t.foldLeft(h)(merge(_, _))
+        case Nil => null
     }
     }
 
@@ -361,6 +362,8 @@ object QueryParser extends StandardTokenParsers with QueryKeywords with Expressi
         case h :: t => { //the left-most part of the identifier (h) can be
             t.foldLeft(id(h).asInstanceOf[Expression])(_.field(_))
         }
+
+        case Nil => null
     }
     }