private Object uncheckedGetElement(int index) {
    if (elementInited[index]) {
      return arrayElements[index].getObject();
    }
    elementInited[index] = true;

    int elementStart = startPosition[index];
    int elementLength = startPosition[index + 1] - elementStart - 1;
    if (arrayElements[index] == null) {
      arrayElements[index] = LazyFactory.createLazyObject(oi.getListElementObjectInspector());
    }
    if (isNull(oi.getNullSequence(), bytes, elementStart, elementLength)) {
      arrayElements[index].setNull();
    } else {
      arrayElements[index].init(bytes, elementStart, elementLength);
    }
    return arrayElements[index].getObject();
  }
Get the element without checking out-of-bound index.
serde/src/java/org/apache/hadoop/hive/serde2/lazy/LazyArray.java