Android - static Context

Question

I need to have have reference to Context in my utils class.

First I am extending Application class and initializing my util class:

public class MyApplication extends Application {

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

And utils class looks like:

public class Utils{

    private static Context sContext;

    private Utils() {
    }

    public static void init(Context context) {
        sContext = context;
    }
}

Is there any possible way to get a leak with such approach?

I can see only one case: when application goes background - Context can be re-created, and so Utils class may be re-initialized even if it will persist in memory.

Any suggestions, please.

Yes this can lead to memory leaks, when screen orientation is changed.. Can you tell me why you need to hold context as your Utils class's private field? — Bhargav, Mar 05 '16 at 16:08
This was just theoretical, of course. But now, how orientation changes affect these classes? There is no any Activity references. — Alex Moore, Mar 05 '16 at 16:11
I guess as long as you are passing in applicationContext to the init methods its fine, but in order to make sure that you are keeping only app context in your `Utils` class you need to do this in init method `sContext = context.getApplicationContext();` — Bhargav, Mar 05 '16 at 16:12
And also instead of holding a static context like that why not make `Utils` class a singleton, and use Dependency Injection in whichever class depends on Utils class. With dagger2 you can actually give scope to injected classes like these, so instead of actually being a singleton for whole app life cycle, you can actually "scope" it to custom abstract scopes you want — Bhargav, Mar 05 '16 at 16:15
if you like I could explain it in more detail in an answer... — Bhargav, Mar 05 '16 at 16:27
Visit http://stackoverflow.com/questions/2002288/static-way-to-get-context-on-android?rq=1 — Rindt Lin, Mar 05 '16 at 16:29
Like @Bhargav pointed out, use ApplicationContext whenever possible rather than AcitivityContext. ActivityContext is renewed everytime the screen orientation changes and keeping references to those is absolutely a bad idea. — Ashim, Mar 05 '16 at 17:12
Sure, but in this case there is no any references to Activity — Alex Moore, Mar 05 '16 at 18:04

score 1 · Accepted Answer · answered Mar 05 '16 at 16:04

1

You should solve as follow:

 public class YourClass extends Application {

        private static Context context;

        public void onCreate()
        {
            super.onCreate();
            YourClass.context = getApplicationContext();
        }

        public static Context getAppContext() {
            return YourClass.context;
        }
    }

How to use:

YourClass.getAppContext();

answered Mar 05 '16 at 16:04

user3449772

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Yes, this is known approach. But question was bit deeper - is there leak possibility when referencing like there? – Alex Moore Mar 05 '16 at 16:08
I think that your solution should not be a problem because the static method is loaded and unloaded instantly and you should not have some memory leak issues. Anyway, it think your code is similar to my solution. – user3449772 Mar 05 '16 at 16:16
Sure, in a normal situation i'd use your approach.But not all situations go ways we want – Alex Moore Mar 05 '16 at 16:18

Android - static Context

1 Answers1