Is passing context through a static class efficient way or not?

Question

In android, I need reference "context" or to say pass "context" to several classes. For this purpose I have implemented a static class which holds the "context" and all other class access context through it.

//let's say I have a static class DataHolder 
//and my main acitivity i.e. whose context need to be refrenced

 public class DataHolder{
        public static Context context;
    }

public class MainActivity extends Activity{
    public void onCreate(Bundle bundle){
     DataHolder.context = getApplicationContext();
   }
}

So, is this process ok to be implemented or it is not the right way to reference in Android application.

Answer 1

The issue here is not about efficiency, but about the inherent risks of storing your context statically.

The context can change in many events, the most likely one is changing the device orientation, so you shouldn't relay on it always. I think you should pass the Context in the constructor to each class you think would use it (or, rather, redesign your code so you don't need it where it's not available, although this may be a bit tricky).

In the worst case scenario, you should try to update it as frequently as you can. But, then again, what's the point in having it always accessible? I think the risks are not worth the laziness (sorry if it sounds rude, I don't mean it to) of making a careful app design.

Answer 2

You should definetely avoid it, since it may lead to a memory leak. Read: Avoiding memory leaks

This means that views have a reference to the entire activity and therefore to anything your activity is holding onto; usually the entire View hierarchy and all its resources. Therefore, if you leak the Context ("leak" meaning you keep a reference to it thus preventing the GC from collecting it), you leak a lot of memory. Leaking an entire activity can be really easy if you're not careful