Instantiate singleton class objects in Android

Question

Can anyone tell me where to instantiate a singleton class object like ArrayList?

I am trying to instantiate in the onCreate() method but its not instantiated. Can any one tell me where to allocate it?

public class SharedVariables extends Application 
{
public static ArrayList<ArrayList<Map<String,String>>>  ArrayOfImageUrlDicts;
public static ArrayList<ArrayList<Map<String,String>>> ArrayOfImageNameDicts;

@Override
public void onCreate()
{
    super.onCreate();
    ArrayOfImageUrlDicts  = new ArrayList<ArrayList<Map<String,String>>>(); 
    ArrayOfImageNameDicts = new ArrayList<ArrayList<Map<String,String>>>();
}
}

It depends what are you trying to do ? How are you gonna use these arraylist — Mojo Risin
– Mojo Risin, Commented Apr 5, 2011 at 6:12

Niklas Schnelle · Accepted Answer · 2011-04-05 06:19:14Z

This is actually not a real Singelton (see Wikipedia for an accurate Description of Singeltons) but a normal static variable. If you want to usemore static variables you may consider using this as it makes things much more beautiful. However to answer your concrete question you can either use a static block where you initialize those variables or initialize them directly after decleration.

public class SharedVariables extends Application 
{
   public static ArrayList<ArrayList<Map<String,String>>>  ArrayOfImageUrlDicts = new ArrayList<ArrayList<Map<String,String>>>();
   public static ArrayList<ArrayList<Map<String,String>>> ArrayOfImageNameDicts = new ArrayList<ArrayList<Map<String,String>>>();

   @Override
   public void onCreate()
   {
      super.onCreate();
   }
}

or

public class SharedVariables extends Application 
{
   public static ArrayList<ArrayList<Map<String,String>>>  ArrayOfImageUrlDicts;
   public static ArrayList<ArrayList<Map<String,String>>> ArrayOfImageNameDicts;
   static 
   {
      ArrayOfImageUrlDicts = new ArrayList<ArrayList<Map<String,String>>>();
      ArrayOfImageNameDicts = = new ArrayList<ArrayList<Map<String,String>>>();
   }
   @Override
   public void onCreate()
   {
      super.onCreate();
   }
}

Adinia · Accepted Answer · 2011-04-22 07:57:36Z

0

public class SharedVariables extends Application 
{

ModelSingleTonclass obj;

public static ArrayList<ArrayList<Map<String,String>>>  ArrayOfImageUrlDicts;
public static ArrayList<ArrayList<Map<String,String>>> ArrayOfImageNameDicts;

@Override
public void onCreate()
{
    super.onCreate();

obj=ModelSingleTonclass.getInstance();

    ArrayOfImageUrlDicts  = new ArrayList<ArrayList<Map<String,String>>>(); 
    ArrayOfImageNameDicts = new ArrayList<ArrayList<Map<String,String>>>();
}
}

edited Apr 22, 2011 at 7:57

Adinia

3,7255 gold badges44 silver badges60 bronze badges

answered Apr 5, 2011 at 6:13

Harinder

11.9k17 gold badges75 silver badges127 bronze badges

Collectives™ on Stack Overflow

Instantiate singleton class objects in Android

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related