Question

Hey! I want to use a singleton class, because if I open the database every activity I get “Leak found”( that happens because I open the database even if it is already open ) . I create a singleton class , but I don’t know how should I use it.

Here is my class:

package com.ShoppingList;

import com.ShoppingList.databases.DbAdapter;

public class DbManager {

    DbAdapter db;

    // singleton
    private static DbManager instance = null;

    private DbManager() {

    }

    public static DbManager getInstance() {
        if (instance == null)
            instance = new DbManager();
        return instance;
    }

    public void setinstance(DbAdapter db){
        this.db=db;
    }

    public DbAdapter getinstancedb(){
        return db;
    }
}

In the first activity I put :

db = new DbAdapter(this);
        db.open();
        DbManager.getInstance().setinstance(db);

and for the next activity : DbManager.getInstance().getinstancedb(); but I get force close for second activity.

Can anyone help me how to use it? Thanks…

Answer 1

You can extend Application class and create there an instance of DbAdapter. This way it will be shared by all your activities.