How to share same data between multiple activities

Question

I have a login session ID which multiple activities need to use. How do I share this common data between multiple activities? Presently, I'm passing the data in the Intent but it is not working properly. For some activities, I pass some other data, and the common data is lost.

Answer 1

Use Singleton class for sharing.

sample code

public class Category {

    private static final Category INSTANCE = new Category();
    public String categoryName = "";
    public int categoryColor = 0;
    public boolean status = false;
    // Private constructor prevents instantiation from other classes
    private Category() {}

    public static Category getInstance() {
        return INSTANCE;
    }
}

in other Activity/Class for setting the value as:

Category cat;
cat=Category.getInstance();

cat.categoryName="some name";
cat.status=ture;

for getting the values every where you want in your application.
Category cat;
cat=Category.getInstance();

String sq=cat.categoryName;
boolean stat=cat.status;

Answer 2

Use shared preferences like this:

SharedPreferences myprefs= this.getSharedPreferences("user", MODE_WORLD_READABLE);
myprefs.edit().putString("session_id", value).commit();

You can retrieve this info across your app like this:

SharedPreferences myprefs= getSharedPreferences("user", MODE_WORLD_READABLE);
String session_id= myprefs.getString("session_id", null);

You should use intents when you want to start another activity from your current activity... also if the child activity is totally dependent on data from parent activity ...use intents