cassandra fixes

Author: otaviojava

cassandra-driver/src/main/java/org/eclipse/jnosql/diana/cassandra/column/CassandraConverter.java

@@ -132,7 +132,11 @@ private static UDT getUDT(String name, UDTValue udtValue) {
     }
 
     private static boolean isUDTIterable(Object result) {
-        return StreamSupport.stream(Iterable.class.cast(result).spliterator(), false)
+        final Iterable<?> iterable = Iterable.class.cast(result);
+        if (!iterable.iterator().hasNext()) {
+            return false;
+        }
+        return StreamSupport.stream(iterable.spliterator(), false)
                 .allMatch(UDTValue.class::isInstance);
     }
 

cassandra-driver/src/main/java/org/eclipse/jnosql/diana/cassandra/column/QueryUtils.java

@@ -128,11 +128,22 @@ private static void insertSingleField(Column column, Insert insert) {
 
     public static BuiltStatement select(ColumnQuery query, String keySpace) {
         String columnFamily = query.getColumnFamily();
-
+        final List<String> columns = query.getColumns();
         if (Objects.isNull(query.getCondition())) {
-            return QueryBuilder.select().all().from(keySpace, columnFamily);
+            if (columns.isEmpty()) {
+                return QueryBuilder.select().all().from(keySpace, columnFamily);
+            } else {
+                return QueryBuilder.select(columns.toArray()).from(keySpace, columnFamily);
+            }
+
         }
-        Select.Where where = QueryBuilder.select().all().from(keySpace, columnFamily).where();
+        Select.Where where;
+        if (columns.isEmpty()) {
+            where = QueryBuilder.select().all().from(keySpace, columnFamily).where();
+        } else {
+            where = QueryBuilder.select(columns.toArray()).from(keySpace, columnFamily).where();
+        }
+
         if (query.getLimit() > 0) {
             if (CassandraQuery.class.isInstance(query)) {
                 where.setFetchSize((int) query.getLimit());