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How to make users come back to a particular activity after they kill the app

I am working on an app, so basically, when the user launches the app for the first time, activity A comes up, which asks the user for a bunch of data. Now, that I have the data, I take the user to activity B. Here, if the user kills the app completely, and relaunches it, the app reopens activity A, instead of B... Is there a way to control this behaviour? I want to be able to control what activity the app should open after a particular action by the user... Note : I am a complete newbie, so I have no idea how to do this.. I tried to ask this up on a google search, but couldn't find anything proper ig.

You can store boolean by shared preference to do that. Here your AcitivityA class. Store user provided data before user land to ActivityB.
public class ActivityA extends AppCompatActivity {
private SharedPreferences prefs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = findViewById(R.id.button);
try {
prefs = PreferenceManager.getDefaultSharedPreferences(this);
boolean firsttimeLoad = prefs.getBoolean("first_time_load", true);
if (!firsttimeLoad) {
sendToB();
}
} catch (Exception e) {
e.printStackTrace();
}
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences.Editor editor = prefs.edit();
editor.putBoolean("first_time_load", false);
editor.commit();
//Store user data here
sendToB();
}
});
}
private void sendToB() {
Intent mainIntent = new Intent(ActivityA.this, ActivityB.class);
startActivity(mainIntent);
finish();
}}

The easiest way to use user data in all over the app. Make a separate class for storing user data and make the getter and setter to get and set the data.
public class UserSharedPrefs {
private SharedPreferences sharedPreferences;
private SharedPreferences.Editor editor;
#SuppressLint("CommitPrefEdits")
public UserSharedPrefs(Context context) {
sharedPreferences = context.getSharedPreferences("UserData", Context.MODE_PRIVATE);
editor = sharedPreferences.edit();
}
public void setIsLogin(boolean isLogin) {
editor.putBoolean("isLogin", isLogin);
editor.apply();
}
public boolean getIsLogin() {
return sharedPreferences.getBoolean("isLogin", false);
}
In Activity A makes the reference of that class and get the data and use it as your need. And send the user to desired Activity
if(userSharedPrefs.getIsLogin()){
moveToActivityB()
}

SharedPreferences not updated

I'm trying to create a simple Settings Activity with a single setting to change the language of the App.
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
android:title="#string/locale">
<ListPreference
android:key="lang"
android:title="#string/language"
android:summary="#string/languageDesc"
android:entries="#array/languages"
android:entryValues="#array/languageValues"
android:defaultValue="#string/locale_en"/>
</PreferenceCategory>
public class TCPreferenceActivity extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
if (key.equals("lang")) {
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("lang", sharedPreferences.getString(key, "en_US"));
editor.commit();
settings();
}
}
public void settings() {
Intent intent = new Intent(this, TCPreferenceActivity.class);
intent.putExtra(PreferenceActivity.EXTRA_SHOW_FRAGMENT, TCPreferenceFragment.class.getName());
intent.putExtra(PreferenceActivity.EXTRA_NO_HEADERS, true);
startActivity(intent);
}
#Override
protected void attachBaseContext(Context newBase) {
SharedPreferences pref = newBase.getSharedPreferences("lang", MODE_PRIVATE);
String lang = pref.getString("lang", null);
Locale locale = new Locale(lang);
Context context = TCContextWrapper.wrap(newBase, locale);
super.attachBaseContext(newBase);
}
}
When I debug the activity, i see the updated value being received in the method onSharedPreferenceChanged.
However when i call the Intent to reload the activity, with the context wrapper in order to change the language, the value received from the call to newBase.getSharedPreferences("lang", MODE_PRIVATE) is still the original unchanged value.
When i click again on the preference in the interface, i see that the value hash changed.
Do I need to save the value?
Why doesn't it changed in the SharedPreferences class?
I'm trying to replicate what0s being done in the exemple here:
Android context.getResources.updateConfiguration() deprecated
Thanks in advance.

Try changing:
SharedPreferences pref = newBase.getSharedPreferences("lang", MODE_PRIVATE);
To:
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(TCPreferenceActivity.this);
For what ever reason, you are loading up private "lang" preferences, which im pretty sure you are not saving to. Use the default preferences instead which the activity should be by default using else where.

I would rather that you user apply() instead of commit().
Unlike commit(), which writes its preferences out to persistent storage synchronously, apply() commits its changes to the in-memory SharedPreferences immediately but starts an asynchronous commit to disk.
Do this;
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("lang", sharedPreferences.getString(key, "en_US"));
editor.apply();

Get attributes from SharedPreferences in android

This is my MainActivity.java where I instanciate static SharedPreferences and it's editor:
public static SharedPreferences settings;
public static SharedPreferences.Editor editor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
settings = PreferenceManager.getDefaultSharedPreferences(this);
editor = settings.edit();
Then I make an AsyncTask call to another java class where I try to store a token in onPostExecute method to this SharedPreferences.
#Override
protected void onPostExecute(String result) {
MainActivity.editor.putString("auth_token", result);
MainActivity.editor.commit();
Log.d("token", MainActivity.settings.getString("auth_token", "Nothing"));
}
This Log.d() method outprints the token value in the console, which is "OK". But then I start an acitivity Next.java where I try to get this token on a screen using this:
TextView text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_next);
String auth_token_string = MainActivity.settings.getString("auth_token", "Nothing");
text = (TextView) findViewById(R.id.logintxt);
text.setText(auth_token_string);
And the result on the screen is the default String "Nothing".
What am I doing wrong here? ...and is this the right way to use SharedPreferences? I got this idea here in this topic.
EDIT:
Code from AuthorizeActivity.java where I call the asyncTask:
public void getToken(String code){
AsyncTask<String, Void, String> tsk = new Api().execute(code);
Intent i = new Intent(this.getBaseContext(), Next.class);
dialog.dismiss();
startActivity(i);
}

Your settings variable is static, it's initialised in onCreate method of MainActivity when you access settings in Next.java it's not initialised yet.
You have access to SharedPreferences in Next.java (it's shared).
EDIT :
add a update method in MainActivity :
public void update() {
Intent i = new Intent(this.getBaseContext(), Next.class);
startActivity(i);
}
and your postExecute should look like this :
#Override
protected void onPostExecute(String result) {
MainActivity.editor.putString("auth_token", result);
MainActivity.editor.commit();
Log.d("token", MainActivity.settings.getString("auth_token", "Nothing"));
((MainActivity) context).update();
}

Do not use the settings from MainActivity, create a new SharedPrefs instance and call getString method.

Edit: I've created an example of how this should be handled on GitHub
Firstly, I would advise that you don't make your members static; they don't need to be static.
On your Next.class (Perhaps you should rename this, it's not clear what it does), you just need to get a handle on the shared preferences again with your new context:
PreferenceManager.getDefaultSharedPreferences(this);
Please note, there's a difference between getDefaultSharedPreferences and getSharedPreferences - use whichever you think it most appropriate.

boolean won't stay on the right input when i kill my app or reboot the device

im building a app, found a java part that lets me show an activity only at first start.
this works but when i kill the app or reboot my phone it goes back, can anyone help me out with this?
im using this in my main activity (Toolz.java)
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (Prefs.firststart == false) {
setContentView(R.layout.toolz);
} else {
Intent i = new Intent(this, First.class);
startActivity(i);
finish();
}
}
#Override
protected void onResume() {
super.onResume();
}
and i added this to First.java
Prefs.firststart=false;
and i made the Prefs.java and added this
public class Prefs {
public static boolean firststart = true;
}

you will need to use SharedPreferences instead o static variable for saving data which also available when app killed or device reboot.
you can see following tutorial how we use SharedPreferences for saving and reading data from SharedPreferences
Shared Preferences

When the app restarts all your code will start from the starting point (i.e Prefs.firststart will be set to true). Instead, you need to make a persistent variable that is saved throughout sessions. If you're using a DB you could use that, or you could use the built-in SharedPreferences, as such:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SharedPreferences prefs = this.getPreferences(MODE_PRIVATE);
if (prefs.contains("started")) {
setContentView(R.layout.toolz);
} else {
//Add the preference:
SharedPreferences.Editor editor = prefs.edit();
editor.putBoolean("started",true);
editor.apply();
Intent i = new Intent(this, First.class);
startActivity(i);
finish();
}
}

When you kill your app, the values are going to reset to their initial values. Your boolean will be equal to true. I suggest saving the state of the variable using SharedPreferences. Check out this other question someone asked about saving.
How to save a state of a variable in android app and use it

Try it like this
//**** First start *****
//you get the prefs for your app using a pref name
String PREFS_NAME = "myAppPrefs";
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
//persist the boolean value in preferences using a key-value approach
editor.putBoolean("pref_app_started", true);
//commit the changes
editor.commit();
and when you start the app you check for that pref
//**** next start *****
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
//now we get the saved boolean using the key we previously uesd when setting it
//the second parameter is the default value for the flag in case it was never set
boolean wasAppStarted = settings.getBoolean("pref_app_started", false);
//now you can use your wasAppStarted flag to decide what you do further

Saving sharedPreferences in a View class

I need to have some information saved, what I have used in the past is sharedpreferences...
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("Data", (Data));
editor.commit();
So I would do something like this to save the Data, however for this project I am using the public class Tab3 extends View implements OnTouchListener type of class and Im not sure if thats why this isnt working but its not I cant use the Shared Prefences onTouch I get an error on getSharedPreferences saying "The method getSharedPreferences(String, int) is undefined for the type Tab3" what do I need to do in order to save this data in some way so I can use it later on in my app?

You need a context to get access to shared preferences. The best way is to create MyApplication as a descendant of Application class, instantiate there the preferences and use them in the rest of your application as MyApplication.preferences:
public class MyApplication extends Application {
public static SharedPreferences preferences;
#Override
public void onCreate() {
super.onCreate();
preferences = getSharedPreferences( getPackageName() + "_preferences", MODE_PRIVATE);
For example, if you need access to your preferences somewhere else, you may call this to read preferences:
String str = MyApplication.preferences.getString( KEY, DEFAULT );
Or you may call this to save something to the preferences:
MyApplication.preferences.edit().putString( KEY, VALUE ).commit();
(don't forget to call commit() after adding or changing preferences!)

I'd do what lenik says but don't make them static, lazy init them instead.
public class MyApplication extends Application {
public SharedPreferences preferences;
public SharedPreferences getSharedPrefs(){
if(preferences == null){
preferences = getSharedPreferences( getPackageName() + "_preferences", MODE_PRIVATE);
}
return preferences;
}
Then in your view:
MyApplication app = (MyApplication) getContext().getApplicationContext();
SharedPreferences settings = app.getSharedPrefs();
As eric says this Application class needs to be declared in your manifest:
<application android:name=".MyApplication"
android:icon="#drawable/icon"
android:label="#string/app_name">
Reference:
getApplicationContext()
Android Global Vars
edit
(From your comment) the issue is that you aren't actually saving any data, this line doesn't make sense you aren't actually saving a variable:
editor.putString("Data", (Data));
Here is an example of the above in use:
MyApplication app = (MyApplication) getContext().getApplicationContext();
SharedPreferences settings = app.getSharedPrefs();
String str = settings.getString("YourKey", null);
And to save something to the preferences:
settings.edit().putString("YourKey", "valueToSave").commit();
A more specific example of using in a custom View would be:
public class MyView extends View {
SharedPreferences settings;
// Other constructors that you may use also need the init() method
public MyView(Context context){
super(context);
init();
}
private void init(){
MyApplication app = (MyApplication) getContext().getApplicationContext();
settings = app.getSharedPrefs();
}
private void someMethod(){ // or onTouch() etc
settings.edit().putString("YourKey", "valueToSave").commit(); //Save your data
}
private void someOtherMethod(){
String str = settings.getString("YourKey", null); //Retrieve your data
}
}