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SharedPreferences In Android

Data storage always makes an issue for developers, especially for beginners, and also when the data is very small. Android provides a very simple solution for small data and for all the primitive types like “String, byte, int” etc. Let us have a look at the code first. In every project of mine I always make a class, mostly with the name of HelperFunctions, and I put the functions to read and to write the data from the shared preferences.

  1. public class HelperFunctions  
  2. {  
  3.     static SharedPreferences preferences;  
  4.   
  5.     //Writes data in shared preference  
  6.     public static void saveInSharedPreferences(Context context, String key, String value) {  
  7.         preferences = PreferenceManager  
  8.             .getDefaultSharedPreferences(context);  
  9.         SharedPreferences.Editor editor = preferences.edit();  
  10.         editor.putString(key, value);  
  11.         editor.apply();  
  12.     }  
  13.   
  14.     //read from SharedPreference  
  15.     public static String readFromSharedPref(Context context, String key) {  
  16.         preferences = PreferenceManager  
  17.             .getDefaultSharedPreferences(context);  
  18.         return preferences.getString(key, null);  
  19.     }  
  20.   
  21. }  
We are done, as whenever you need to store the data that you used most, you can just write.
  1. HelperFunctions.saveInSharedPreferences(context, Constants.PROFILE_ID, mData);  
The data is saved now and similarly you can get it, as shown below.
  1. String userid = HelperFunctions.readFromSharedPref(context, Constants. PROFILE_ID);  
Note

In place of the constants, you can write your String “PreferenceName”.

Let’s have a look at the advantages.

 

  • In small enterprise apps, you can save the user login credentials to use them in future or to send the data on the server with the user Id etc.
  • If you have to update the application at the specific time, in the first install of your Application, you can check for Boolean stored SharedPreferences.
  • Even if you want to pass JSON between the activities, you can easily do this even if you are a beginner.
    The code given above is tested and works fine, when you can copy the code. If you find any improvements, share and help others to write better code.