String getInternalNames(String columnNames) {
    if (columnNames == null) {
      return null;
    }
    if (columnNames.isEmpty()) {
      return "";
    }

    StringBuilder sb = new StringBuilder();
    int numStrings = columnNames.split(",").length;
    sb.append("_col0");
    for (int i = 1; i < numStrings; i++) {
      sb.append(",");
      sb.append(HiveConf.getColumnInternalName(i));
    }
    return sb.toString();
  }
This test has been added to account for HCATALOG-436
 We write out columns with "internal column names" such
 as "_col0", but try to read with regular column names.
hcatalog/core/src/test/java/org/apache/hive/hcatalog/data/TestJsonSerDe.java