SharedPreferences Logout not working

Question

I have 2 Activities, Authentication and Mainpage.

In Authentication, it checks if the user is logged in, if the user is logged in, redirect it to Mainpage.class. This is how Authentication checks if the user is logged in and redirect it.

SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
boolean isLoggedIn = blockSession.getBoolean("logged_in", false);
if(isLoggedIn){
    Intent intent = new Intent(this, Mainpage.class);
    startActivity(intent);
}

In Mainpage, I have a button which is a logout button and onClick event it use the logOut function that I've created. This is how logout button works:

void logOut(){
    SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
    SharedPreferences.Editor blockEdit = blockSession.edit();
    blockEdit.clear();
    blockEdit.apply();
    finish();

    Intent intent = new Intent(Mainpage.this, Authentication.class);
    startActivity(intent);
}

The problem here is when I click the logout button, I just kept redirecting to Mainpage.

Answer 1

The problem is that you are finishing the activity before starting the Intent..That is why it shows MainPage when the logout() is called..Instead, you will have to finish the activity after the intent has been called.

Thus replace your code as follows

void logOut(){
    SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
    SharedPreferences.Editor blockEdit = blockSession.edit();
    blockEdit.clear();
    blockEdit.apply();
    //finish();       /****<-----commented out this line---****/
    Intent intent = new Intent(Mainpage.this, Authentication.class);
    startActivity(intent);

    finish();        /****<------Moved to here---****/
}

UPDATE

Since you are adding onClick attribute in your xml for the button and you are getting an error

java.lang.IllegalStateException: Could not find method logOut(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'logoutButton'

Replace your function as follows

void logOut(View v){
    SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
    SharedPreferences.Editor blockEdit = blockSession.edit();
    blockEdit.clear();
    blockEdit.apply();
    //finish();       /****<-----commented out this line---****/
    Intent intent = new Intent(Mainpage.this, Authentication.class);
    startActivity(intent);

    finish();        /****<------Moved to here---****/
}

However, I dont think it's a good idea to solve this way. You should implement onClickListener inside your adapter or your fragment.

Answer 2

Try this, hope it helps

void logOut(){
    SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
    SharedPreferences.Editor blockEdit = blockSession.edit();
    blockEdit.clear();
    blockEdit.commit(); // to apply the changes
    finish();

    Intent intent = new Intent(Mainpage.this, Authentication.class);
    startActivity(intent);
}

Answer 3

Try it.

 SharedPreferences mySPref = PreferenceManager.getDefaultSharedPreferences(this);
        SharedPreferences.Editor editor = mySPrefs.edit();
        editor.remove(String key);
        editor.apply();

Answer 4

Replace your this line of code

 blockEdit.apply();

with

 blockEdit.commit();

Followed by your activity calling intent.Hope it helps.

Answer 5

Put finish() here in the code of yours

SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0); 
boolean isLoggedIn = blockSession.getBoolean("logged_in", false);
if(isLoggedIn){
Intent intent = new Intent(this, Mainpage.class);
startActivity(intent);
finish();
}

UPDATE
I went through your code and found a small mistake in it :
In your OnCreate method you are using :

SharedPreferences blockSession  = PreferenceManager.getDefaultSharedPreferences(this);
    boolean isLoggedIn  = blockSession.getBoolean("logged_in", false);
    if(!isLoggedIn){
        Intent intent  = new Intent(this, Mainpage.class);
        startActivity(intent);
        finish();
    }

Mistakes :
You are getting your sharedPreference value in on create method But when you are clearing sharedPreference on logout it doesn't have any shaved sharedPreference value . so it takes false as default value as you mentioned here :

 boolean isLoggedIn  = blockSession.getBoolean("logged_in", false); // false is default value.

And you if conditioned is always true because you have false value every time you logout.

Solution :
change if condition as follows :

if(isLoggedIn){
        Intent intent  = new Intent(this, Mainpage.class);
        startActivity(intent);
        finish();
    }

Answer 6

Just reset your SharedPreferences KEY logged_in value to false using blockEdit.putBoolean("logged_in", false) and commit.

Try this:

void logOut(View view) {

    SharedPreferences blockSession = this.getSharedPreferences("blockSession", 0);
    SharedPreferences.Editor blockEdit = blockSession.edit();

    // Set logged_in value to false
    blockEdit.putBoolean("logged_in", false);
    blockEdit.commit();

    // Start Authentication     
    Intent intent = new Intent(Mainpage.this, Authentication.class);
    startActivity(intent);

    // Finish MainPage 
    finish();
}

#. Best practice is to create a common class for session management and use this from anywhere in your application as per your needs.

Crate a SessionManager class like below:

public class SessionManager {

    // LogCat tag
    private static String TAG = SessionManager.class.getSimpleName();

    Context context;

    // Shared Preferences
    SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;

    // Shared pref mode
    int PRIVATE_MODE = 0;

    // Shared preferences file name
    private static final String PREF_NAME = "MY_APP";

    private static final String KEY_IS_LOGGED_IN = "IS_LOGGED_IN";

    private static final String KEY_USER_ID = "USER_ID";
    private static final String KEY_USER_EMAIL = "USER_EMAIL";
    private static final String KEY_USER_USERNAME = "USER_USERNAME";

    public SessionManager(Context context) {
        this.context = context;
        sharedPreferences = context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
        editor = sharedPreferences.edit();
    }

    public void setLogin(boolean isLoggedIn) {

        editor.putBoolean(KEY_IS_LOGGED_IN, isLoggedIn);

        // commit changes
        editor.commit();

        Log.d(TAG, "User login session modified!");
    }

    public boolean isLoggedIn() {
        return sharedPreferences.getBoolean(KEY_IS_LOGGED_IN, false);
    }

    public void setUserId(int id) {
        editor.putInt(KEY_USER_ID, id);
        editor.commit();
    }

    public int getUserId() {
        return sharedPreferences.getInt(KEY_USER_ID, 0);
    }

    public void setUsername(String username) {
        editor.putString(KEY_USER_USERNAME, username);
        editor.commit();
    }

    public String getUsername() {
        return sharedPreferences.getString(KEY_USER_USERNAME, "user1234");
    }

    public void setEmail(String email) {
        editor.putString(KEY_USER_EMAIL, email);
        editor.commit();
    }

    public String getEmail() {
        return sharedPreferences.getString(KEY_USER_EMAIL, "default@gmail.com");
    }
}

USE:

LOGIN:

SessionManager sessionManager = new SessionManager(getApplicationContext());
sessionManager.setLogin(true);
sessionManager.setUserId(userId);

// Launch MainPage
Intent intent = new Intent(LoginActivity.this, MainActivity.class);
startActivity(intent);
finish();

LOGOUT:

SessionManager sessionManager = new SessionManager(getApplicationContext());
sessionManager.setLogin(false);

// Launch LoginPage
Intent intent = new Intent(MainActivity.this, LoginActivity.class);
startActivity(intent);
finish();

Hope this will help~