StackOverflow2013

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POSolution to access global data from everywhere - efficiently
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copied!<p>I need to find a solution that holds and accesses large chunks of complex global data and methods. It has to be accessible from within activities and normal instance variables of various data classes.</p> <p>This is how I have done it. I would just like to know if there is anything wrong with it or if there is a better/cleaner way.</p> <p>First I extend <code>Application</code> like recommended many times...</p> <pre><code>public class MainDataManager extends Application{ public ... large chunks of data in arrays, lists, sets,.... //static variable for singleton access from within instance variables of other classes public static MainDataManager mainDataManager; //create and init the global data, and store it in the static variable of the class @Override public void onCreate() { super.onCreate(); //in case it should get called more than once for any reason if (mainDataManager == null) { init(); mainDataManager = this; } } </code></pre> <p>Now accessing it from within activities like everywhere recommended...</p> <pre><code>MainDataManager mainDataManager = (MainDataManager)getApplicationContext(); </code></pre> <p>And since I need to access it from normal instances of data classes ...</p> <pre><code>public class MyDataClass { public MainDataManager mainDataManager; public String name; public MyDataClass(String namex) { this.name = namex; //this is why I defined the static variable within MainDataManager, so //one has access to it from within the instance of MyDataClass this.mainDataManager = MainDataManager.mainDataManager; } public void examplesForAccessing() { //some examples on how to access the global data structure and associated methods mainDataManager.someMethodAccess(); xyz = mainDataManager.someDataAccess; mainDataManager.someIndirectMethodAccess.clear(); mainDataManager.someOtherData = false; } } </code></pre> <p>Since I have not done this so far, I would like to know if there is anything wrong with this. Memory, efficiency, ...</p> <p>Thanks very much!</p> <p>May I add a little sidenote? I could also have just used a class <code>MainDataClass</code> and access by <code>MainDataClass.var or MainDataClass.method().</code> Is there any REAL disadvantage? </p> <p>Is the data in both cases held in heap/stack?</p>

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