android程序小白代码什么意思啊，看不大懂

public abstract class AbstractSQLManager {

public static final String TAG = AbstractSQLManager.class.getName();//名称

private static DatabaseHelper databaseHelper;
private static SQLiteDatabase sqliteDB;

public AbstractSQLManager() {
    openDatabase(ECApplication.getInstance(), CCPAppManager.getVersionCode());
}

private void openDatabase(Context context, int databaseVersion) {
    if (databaseHelper == null) {
        databaseHelper = new DatabaseHelper(context,this , databaseVersion);
    }
    //DatabaseManager.initializeInstance(databaseHelper);
    if (sqliteDB == null) {
        sqliteDB = databaseHelper.getWritableDatabase();
        //sqliteDB = DatabaseManager.getInstance().openDatabase();
    }

}

public void destroy() {
    try {
        if (databaseHelper != null) {
            databaseHelper.close();
        }
        closeDB();
    } catch (Exception e) {
        LogUtil.e(e.toString());
    }
}

private void open(boolean isReadonly) {
    if (sqliteDB == null) {
        if (isReadonly) {
            sqliteDB = databaseHelper.getReadableDatabase();
        } else {
            sqliteDB = databaseHelper.getWritableDatabase();/*DatabaseManager.getInstance().openDatabase()*/;
        }
    }
}

public final void reopen() {
    closeDB();
    open(false);
    LogUtil.w("[SQLiteManager] reopen this db.");
}

private void closeDB() {
    if (sqliteDB != null) {
        //DatabaseManager.getInstance().closeDatabase();
         sqliteDB.close();
         sqliteDB = null;
    }
}

protected final SQLiteDatabase sqliteDB() {
    open(false);
    return sqliteDB;
}

一个数据库管理工具，开关数据库用

这不是一个SQLite数据库管理工具类么

数据库管理工具类,进行开关数据库!