public static boolean parseBoolean(byte[] arr, int st, int len) {
    switch (len) {
    case 5:
      return !FalseValues.FALSE.accept(arr, st);
    case 3:
      return !FalseValues.OFF.accept(arr, st);
    case 2:
      return !FalseValues.NO.accept(arr, st);
    case 1:
      return !FalseValues.ZERO.accept(arr, st);
    case 0:
      return false;
    default:
      return true;
    }
  }
Parses a boolean from string

Accepts "false","off","no","0" and "" as FALSE
All other values are interpreted as true.
serde/src/java/org/apache/hadoop/hive/serde2/objectinspector/primitive/PrimitiveObjectInspectorUtils.java