public class DatabaseFactory extends Factory {

    private Database database;

    @Override
    public Database createDatabase(String databasetype) {
        switch (databasetype) {
            case "Mysql":
                database = new Mysql();
                break;
            case "Oracle":
                database = new Oracle();
                break;
            case "DB2":
                database = new DB2();
                break;
            default:
                database = null;
        }
        return database;
    }

    @Override
    public void getConnection(Database database) {
        //你還可以定義獲取資料庫連線物件的方法，也是在實現類裡面寫方法
        database.Connection();
    }
}