private GenericUDF getGenericUDFForCast(TypeInfo castType) throws HiveException {
UDF udfClass = null;
GenericUDF genericUdf = null;
switch (((PrimitiveTypeInfo) castType).getPrimitiveCategory()) {
case BYTE:
udfClass = new UDFToByte();
break;
case SHORT:
udfClass = new UDFToShort();
break;
case INT: