How to save array to memory in Android

Question

i'm new to android and i'ld like to understand how i can save an array to memory. I don't mean internal memory, as i know about shared preferences, external storage and sqlite. I'm looking at something within the range of RAM/Heap.

The actual challenge is that i have a string array of names. I get the names from an sqlite database when app is first started.

e.g

String[] names = new String[] {"dave", "james", "tommy" }

This list can grow to contain over 10000 items.

In another activity, i want to check if some names exist in the list. I don't want to query the database back and forth to achieve this. That is why i'm thinking that saving in memory may just be the best bet as it can improve performance.

So i'ld like to know how to save this array in memory and read from it in another activity. I already know how to manage my RAM i'm just looking for ways to get this info there and read from it.

Thanks

Best bet is to use share preferences. Then use gson to serialize the data into a string json structure. If you just sending across activities use parceble interface for serialization. This link is excellent. developer.android.com/training/basics/data-storage/… For Gson a quick starter howtodoinjava.com/best-practices/… For parcelable survivingwithandroid.com/2015/05/… Happy reading! — Remario
– Remario, Commented Mar 11, 2017 at 16:53
A SQL query of SELECT name FROM names WHERE name LIKE "othername" is a really cheap SQL operation, so why not do that? — OneCricketeer
– OneCricketeer, Commented Mar 11, 2017 at 16:57

Community · Accepted Answer · 2017-05-23 12:32:29Z

2

Create a Singleton Pattern and put your array into it and you can share your array across your app instance but remember this singleton class will be destroyed with the app so will your you array inside it.

This is how a singleton is created.

class Bar {
private static class ArrayHolder {
    public static List<String> array = new ArrayList<>();
}

public static Bar getArray() {
    return array;
}
}

Whenever you need to access your array just do this ArrayHolder.getArray()

edited May 23, 2017 at 12:32

CommunityBot

11 silver badge

answered Mar 11, 2017 at 16:58

Rahul Kumar

5,2295 gold badges35 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Andy Turner Over a year ago

What's the purpose of the ArrayHolder class here? It looks like you're trying to do the lazy holder idiom, incorrectly; but the laziness looks unnecessary.

Tajinere Over a year ago

can i get the data from the array in another activity using the singleton approach?

Collectives™ on Stack Overflow

How to save array to memory in Android

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related