Android Shared preferences for creating one time activity (example) [closed]

I have three activities A,B and C where A and B are forms and after filling and saving the form data in database(SQLITE). I am using intent from A to B and then B to C.What i want is that every time I open my app I want C as my home screen and not A and B anymore.

I guess shared preferences would work for this, but I cannot find a good example to give me a starting place. Any help would be appreciated.


Setting values in Preference:

// MY_PREFS_NAME - a static String variable like: 
//public static final String MY_PREFS_NAME = "MyPrefsFile";
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
 editor.putString("name", "Elena");
 editor.putInt("idName", 12);
 editor.apply();

Retrieve data from preference:

SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE); 
String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
int idName = prefs.getInt("idName", 0); //0 is the default value.

More info:

Using Shared Preferences

Shared Preferences


Create SharedPreferences

SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE); 
Editor editor = pref.edit();

Storing data as KEY/VALUE pair

editor.putBoolean("key_name1", true);           // Saving boolean - true/false
editor.putInt("key_name2", "int value");        // Saving integer
editor.putFloat("key_name3", "float value");    // Saving float
editor.putLong("key_name4", "long value");      // Saving long
editor.putString("key_name5", "string value");  // Saving string

// Save the changes in SharedPreferences
editor.apply(); // commit changes

Get SharedPreferences data

// If value for key not exist then return second param value - In this case null

boolean userFirstLogin= pref.getBoolean("key_name1", true);  // getting boolean
int pageNumber=pref.getInt("key_name2", 0);             // getting Integer
float amount=pref.getFloat("key_name3", null);          // getting Float
long distance=pref.getLong("key_name4", null);          // getting Long
String email=pref.getString("key_name5", null);         // getting String

Deleting Key value from SharedPreferences

editor.remove("key_name3"); // will delete key key_name3
editor.remove("key_name4"); // will delete key key_name4

// Save the changes in SharedPreferences
editor.apply(); // commit changes

Clear all data from SharedPreferences

 editor.clear();
 editor.apply(); // commit changes

How to Intialize?

// 0 - for private mode`
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0); 

Editor editor = pref.edit();

How to Store Data In Shared Preference?

editor.putString("key_name", "string value"); // Storing string

OR

editor.putInt("key_name", "int value"); //Storing integer

And don't forget to apply :

editor.apply();

How to retrieve Data From Shared Preferences ?

pref.getString("key_name", null); // getting String

pref.getInt("key_name", 0); // getting Integer

Hope this will Help U :)


You can create your custom SharedPreference class

public class YourPreference {   
    private static YourPreference yourPreference;
    private SharedPreferences sharedPreferences;

    public static YourPreference getInstance(Context context) {
        if (yourPreference == null) {
            yourPreference = new YourPreference(context);
        }
        return yourPreference;
    }

    private YourPreference(Context context) {
        sharedPreferences = context.getSharedPreferences("YourCustomNamedPreference",Context.MODE_PRIVATE);
    }

    public void saveData(String key,String value) {
        SharedPreferences.Editor prefsEditor = sharedPreferences.edit();
        prefsEditor .putString(key, value);
        prefsEditor.commit();           
    }

    public String getData(String key) {
        if (sharedPreferences!= null) {
           return sharedPreferences.getString(key, "");
        }
        return "";         
    }
}

You can get YourPrefrence instance like:

YourPreference yourPrefrence = YourPreference.getInstance(context);
yourPreference.saveData(YOUR_KEY,YOUR_VALUE);

String value = yourPreference.getData(YOUR_KEY);

I just found all the above examples just too confusing, so I wrote my own. Code fragments are fine if you know what you're doing, but what about people like me who don't?

Want a cut-n-paste solution instead? Well here it is!

Create a new java file and call it Keystore. Then paste in this code:

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;

public class Keystore { //Did you remember to vote up my example?
    private static Keystore store;
    private SharedPreferences SP;
    private static String filename="Keys";

private Keystore(Context context) {
    SP = context.getApplicationContext().getSharedPreferences(filename,0);
}

public static Keystore getInstance(Context context) {
    if (store == null) {
        Log.v("Keystore","NEW STORE");
        store = new Keystore(context);
    }
    return store;
}

public void put(String key, String value) {//Log.v("Keystore","PUT "+key+" "+value);
    Editor editor = SP.edit();
    editor.putString(key, value);
    editor.commit(); // Stop everything and do an immediate save!
    // editor.apply();//Keep going and save when you are not busy - Available only in APIs 9 and above.  This is the preferred way of saving.
}

public String get(String key) {//Log.v("Keystore","GET from "+key);
    return SP.getString(key, null);

}

public int getInt(String key) {//Log.v("Keystore","GET INT from "+key);
    return SP.getInt(key, 0);
}

public void putInt(String key, int num) {//Log.v("Keystore","PUT INT "+key+" "+String.valueOf(num));
    Editor editor = SP.edit();

    editor.putInt(key, num);
    editor.commit();
}


public void clear(){ // Delete all shared preferences
    Editor editor = SP.edit();

    editor.clear();
    editor.commit();
}

public void remove(){ // Delete only the shared preference that you want
    Editor editor = SP.edit();

    editor.remove(filename);
    editor.commit();
}
}

Now save that file and forget about it. You're done with it. Now go back into your activity and use it like this:

public class YourClass extends Activity{

private Keystore store;//Holds our key pairs

public YourSub(Context context){
    store = Keystore.getInstance(context);//Creates or Gets our key pairs.  You MUST have access to current context!

    int= store.getInt("key name to get int value");
    string = store.get("key name to get string value");

    store.putInt("key name to store int value",int_var);
    store.put("key name to store string value",string_var);
    }
}