Android SQLite助手 - 我应该在哪里关闭连接？

Question

我编写了一个简单的数据库帮助程序类，以便从多个活动中更加干净地访问数据库。

这是班级：

public class DatabaseHandler extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "name";
    private static final String TABLE_SCORES = "scores";
    private static final String KEY_ID = "id";
    private static final String KEY_SCORE = "score";
    private static final String KEY_DATE = "date";

    SQLiteDatabase database;

    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        database = this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase database) {
        String CREATE_SCORES_TABLE = "CREATE TABLE " + TABLE_SCORES + "("
                + KEY_ID + " INTEGER PRIMARY KEY," + KEY_SCORE + " INTEGER,"
                + KEY_DATE + " TEXT" + ")";
        database.execSQL(CREATE_SCORES_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
        database.execSQL("DROP TABLE IF EXISTS " + TABLE_SCORES);
        onCreate(database);
    }

    void addScore(int score){

        SimpleDateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy", Locale.US);

        String currentDateandTime = dateFormat.format(new Date());

        ContentValues values = new ContentValues();
        values.put(KEY_SCORE, score);
        values.put(KEY_DATE, currentDateandTime);

        database.insert(TABLE_SCORES, null, values);
        //database.close();
    }

    void delete(){
        database.delete(TABLE_SCORES, null, null);
    }


    public List<Score> getAllScores(){
        List<Score> scoresList = new ArrayList<Score>();
        String selectQuery = "SELECT * FROM " + TABLE_SCORES + " ORDER BY " + KEY_SCORE +" DESC LIMIT 10";
        Cursor cursor = database.rawQuery(selectQuery, null);

        if(cursor.moveToFirst()){
            do{
                Score score = new Score();
                score.setId(Integer.parseInt(cursor.getString(0)));
                score.setScore(Integer.parseInt(cursor.getString(1)));
                score.setDate(cursor.getString(2));

                scoresList.add(score);
            } while (cursor.moveToNext());
        }

        return scoresList;
    }

    public int getHighscore() {
        String selectQuery = "SELECT " + KEY_SCORE + " FROM " + TABLE_SCORES + " ORDER BY " + KEY_SCORE +" DESC LIMIT 1";
        SQLiteDatabase database = this.getWritableDatabase();
        Cursor cursor = database.rawQuery(selectQuery, null);
        if(cursor.moveToFirst()){
            return cursor.getInt(0);
        }
        else return 0;
    }

    public int getLastScoreID(){
        String selectQuery = "SELECT " + KEY_ID + " FROM " + TABLE_SCORES + " ORDER BY " + KEY_ID + " DESC LIMIT 1";
        SQLiteDatabase database = this.getWritableDatabase();
        Cursor cursor = database.rawQuery(selectQuery, null);
        if(cursor.moveToFirst()){
            return cursor.getInt(0);
        }
        else return -1;
    }

    public int getLastScoreValue(){
        String selectQuery = "SELECT " + KEY_SCORE + " FROM " + TABLE_SCORES + " ORDER BY " + KEY_ID + " DESC LIMIT 1";
        Cursor cursor = database.rawQuery(selectQuery, null);
        if(cursor.moveToFirst()){
            return cursor.getInt(0);
        }
        else return -1;
    }
}

以下是问题： 我应该把database.close（）放在哪里？在Java中没有像析构函数这样的东西（我真的不想最终确定（）这个......）。

最好的问候。