Garbage collect the instance when you are done with it
Source
void close() { _wordData = null; _wordLength = null; _totalWord = null; _compressed = null; _byteAcc = null; if (_books != null) { for (int i = 0; i < _books.length; i++) { if (_books[i] != null) { _books[i].close(); _books[i] = null; } } } if (_pdbAccess != null) { _pdbAccess.close(); _pdbAccess = null; } }