android how to use getApplication and getApplicationContext from non activity service class

Question

I m using extending application class on Android to share my data across the entire app   I can use getApplication   method from all my activities   However  there are certain custom helper classes I created  for example  an XMLHelper class which does not inherit from any activity   service class   Here the getApplication   method is not available   How do I sort this out and what are the best design practices to solve this

User · Answer

Casting a Context object to an Activity object compiles fine   Try this      Activity  mContext  getApplication

User · Answer

try this  calling the activity in the constructor  public class WebService   private Activity activity           public WebService Activity  activity               activity  activity              helper new Helper activity

User · Answer

The getApplication   method is located in the Activity class  so whenever you want  getApplication   in a non activity class you have to pass an Activity instance to the constructor of that non activity class   assume that test is my non activity class   Test test   new Test this     In that class i have created one constructor    public Class Test        public Activity activity      public Test  Activity act                 this activity   act              Now here you can get getApplication

User · Answer

Either pass in a Context  so you can access resources   or make the helper methods static

User · Answer

The getApplication   method is located in the Activity class  that s why you can t access it from your helper class   If you really need to access your application context from your helper  you should hold a reference to the activity s context and pass it on invocation to the helper

User · Answer

Sending your activity context to other classes could cause memoryleaks because holding that context alive is the reason that the GC can t dispose the object

User · Answer

In order to avoid to pass this argument i use class derived from Application  public class MyApplication extends Application    private static Context sContext    Override public void onCreate         super onCreate        sContext    getApplicationContext        public static Context getContext         return sContext      and invoke MyApplication getContext   in Helper classes   Don t forget to update the manifest    lt  xml version  1 0  encoding  utf-8   gt    lt manifest xmlns android  http   schemas android com apk res android   package  com example  gt          lt application         android name   MyApplication         android allowBackup  true          android icon   mipmap ic launcher          android label   string app name  gt             lt activity     gt                               lt  activity gt        lt  application gt    lt  manifest gt

[android] android: how to use getApplication and getApplicationContext from non activity / service class

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