问在android sqlite中未调用的升级方法

EN

     public class DatabaseHelper extends SQLiteOpenHelper {

        private  static final String DB_NAME = "dictionary.db";
        private static final int DB_VERSION = 1;
        private String DB_PATH = null;
        private  static final String TABLE_DICTIONARY = "dictionary";
        private  static final String TABLE_BOOKMARK= "bookmark";
        private static final String COL_ID = "id";
        private static final String COL_WORD = "word";
        private static final String COL_DEFINITION = "definition";
        private Context mcontext;
        private SQLiteDatabase mDatabase;


        public DatabaseHelper( Context context) {
            super(context, DB_NAME, null, DB_VERSION);
            this.mcontext = context;
            this.DB_PATH = "/data/data/" + context.getPackageName() + "/" + "databases/";
            //this.getReadableDatabase();
        }

        public void createDataBase() throws IOException {

            boolean dbExist = checkDataBase();
            if (!dbExist) {
                this.getReadableDatabase();
                try {
                    mcontext.deleteDatabase(DB_NAME);
                    copyDataBase();
                } catch (IOException e) {
                    throw new Error("Error copying database");
                }
            }
        }

        public boolean checkDataBase() {
            SQLiteDatabase checkDB = null;
            try {
                String myPath = DB_PATH + DB_NAME;
                checkDB = SQ

LiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
            e.printStackTrace();
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    private void copyDataBase() throws IOException {

        InputStream myInput = mcontext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    public void openDatabase() throws SQLException {
        String myPath = DB_PATH + DB_NAME;
        mDatabase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
    }

    @Override
    public synchronized void close() {
        if (mDatabase != null)
            mDatabase.close();
        super.close();
    }

         @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        if (newVersion > oldVersion) {
            try {
                copyDataBase();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        Log.d(TAG, "onUpgrade:called ");
    }
}