如何创建基于 ActionResolver 的 jdbc sqlite 连接？

Question

I've followed the instructions at the wiki ( https://code.google.com/archive/p/libgdx-users/wikis/SQLite.wiki ) but I'm not sure how to actually use the db connection. I've looked at the jdbc tutorial at http://www.tutorialspoint.com/jdbc/jdbc-sample-code.htm and I guess I'm stuck on the connection.

The resolver code

public interface ActionResolver {
public Connection getConnection();
}

public class DesktopActionResolver implements ActionResolver {
public Connection getConnection() {
    String url = "jdbc:sqlite:db.sqlite";
    try {
        Class.forName("org.sqlite.JDBC");
        return DriverManager.getConnection(url);
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return null;
}
}

public class AndroidActionResolver implements ActionResolver {

Handler uiThread;
Context appContext;

public AndroidActionResolver(Context appContext) {
    uiThread = new Handler();
    this.appContext = appContext;
}

@Override
public Connection getConnection() {
    String url = "jdbc:sqldroid:/data/data/com.myapp/databases/db.sqlite";
    try {
        Class.forName("org.sqldroid.SQLDroidDriver").newInstance();
        return DriverManager.getConnection(url);
    } catch (InstantiationException e) {
        Log.e("sql", e.getMessage());
    } catch (IllegalAccessException e) {
        Log.e("sql", e.getMessage());
    } catch (ClassNotFoundException e) {
        Log.e("sql", e.getMessage());
    } catch (SQLException e) {
        Log.e("sql", e.getMessage());
    }
    return null;
}
}

The jdbc tutorial has

conn = DriverManager.getConnection(DB_URL,USER,PASS);

Can someone explain or point me in the right direction on how to use the connection from the ActionResolvers?

What do I need to do in order to have the conn available in the rest of my code?

I would think it would be something like

Connection conn = ActionResolver.getConnection();

but that's not it.

Answer 1

After some trial and error and a lot of reading I have gotten this to work. Here is the code

MyGame.java

public class MyGame extends Game {
    public ActionResolver actionResolver;

    public MyGame(ActionResolver actionResolver) {
        super();
        this.actionResolver = actionResolver;
    }

    public void create() {
        Connection conn = actionResolver.getConnection();
        try {
            Statement statment = conn.createStatement();
            ResultSet resultSet = statment.executeQuery("select * from items");
            while (resultSet.next())
            {
                System.out.println(resultSet.getString("name"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

AndroidLauncher.java change

initialize(new MyGame(), config);

to

initialize(new MyGame(new AndroidActionResolver(this.getBaseContext())), config);

DesktopLauncher.java change

new LwjglApplication(new MyGame(), config);

to

new LwjglApplication(new MyGame(new DesktopActionResolver()), config);