Android: Remove all the previous activities from the back stack

The solution proposed here worked for me:

Java

Intent i = new Intent(OldActivity.this, NewActivity.class);
// set the new task and clear flags
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(i);

Kotlin

val i = Intent(this, NewActivity::class.java)
// set the new task and clear flags
i.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
startActivity(i)

However, it requires API level >= 11.

Here is one solution to clear all your application's activities when you use the logout button.

Every time you start an Activity, start it like this:

Intent myIntent = new Intent(getBaseContext(), YourNewActivity.class);
startActivityForResult(myIntent, 0);

When you want to close the entire app, do this:

setResult(RESULT_CLOSE_ALL);
finish();

RESULT_CLOSE_ALL is a final global variable with a unique integer to signal you want to close all activities.

Then define every activity's onActivityResult(...) callback so when an activity returns with the RESULT_CLOSE_ALL value, it also calls finish():

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch(resultCode)
    {
    case RESULT_CLOSE_ALL:
        setResult(RESULT_CLOSE_ALL);
        finish();
    }
    super.onActivityResult(requestCode, resultCode, data);
}

This will cause a cascade effect that closes all your activities.

This is a hack however and uses startActivityForResult in a way that it was not designed to be used.

Perhaps a better way to do this would be using broadcast receivers as shown here:

On logout, clear Activity history stack, preventing "back" button from opening logged-in-only Activites

See these threads for other methods as well:

Android: Clear the back stack

Finish all previous activities

To clear the activity stack completely you want to create a new task stack using TaskStackBuilder, for example:

Intent loginIntent = LoginActivity.getIntent(context);
TaskStackBuilder.create(context).addNextIntentWithParentStack(loginIntent).startActivities();

This will not only create a new, clean task stack, it will also allow for proper functioning of the "up" button if your LoginActivity has a parent activity.

finishAffinity() added in API 16. Use ActivityCompat.finishAffinity() in previous versions. When you will launch any activity using intent and finish the current activity. Now use ActivityCompat.finishAffinity() instead finish(). it will finish all stacked activity below current activity. It works fine for me.

What worked for me

Intent intent = new Intent(getApplicationContext(), HomeActivity.class);
ComponentName cn = intent.getComponent();
Intent mainIntent = IntentCompat.makeRestartActivityTask(cn);
startActivity(mainIntent);

You can try finishAffinity(), it closes all current activities and works on and above Android 4.1

One possible solution what I can suggest you is to add android:launchMode="singleTop" in the manifest for my ProfileActivity. and when log out is clicked u can logoff starting again you LoginActivity. on logout u can call this.

Intent in = new Intent(Profile.this,Login.class);
                in.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(in);
                finish();

For API 11+ you can use Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK like this:

Intent intent = new Intent(this, MyActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK);
this.startActivity(intent);

It will totally clears all previous activity(s) and start new activity.

Use the following for activity

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);

remove CLEAR_TASK flag for fragment use.

I hope this may use for some people.

I am also facing the same issue..

in the login activity what i do is.

    Intent myIntent = new Intent(MainActivity.this, ActivityLoggedIn.class);
    finish();
    MainActivity.this.startActivity(myIntent);  

on logout

   Intent myIntent = new Intent(ActivityLoggedIn.this, MainActivity.class);
   finish();
   ActivityLoggedIn.this.startActivity(myIntent);

This works well but when i am in the ActivityLoggedIn and i minimize the app and click on the launcher button icon on the app drawer, the MainActivity starts again :-/ i am using the flag

android:LaunchMode:singleTask 

for the MainActivity.

None of the intent flags worked for me, but this is how I fixed it:

When a user signs out from one activity I had to broadcast a message from that activity, then receive it in the activities that I wanted to close after which I call finish(); and it works pretty well.

Just keep

Intent intent = new Intent(ProfileActivity.this,
    LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
startActivity(intent);

Try this it will work:

Intent logout_intent = new Intent(DashboardActivity.this, LoginActivity.class);
logout_intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
logout_intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
logout_intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
startActivity(logout_intent);
finish();

In API level 11 or greater, use FLAG_ACTIVITY_CLEAR_TASK and FLAG_ACTIVITY_NEW_TASK flag on Intent to clear all the activity stack.

Intent i = new Intent(OldActivity.this, NewActivity.class);
// set the new task and clear flags
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |  Intent.FLAG_ACTIVITY_CLEAR_TASK)
startActivity(i);

Advanced, Reuseable Kotlin:

You can set the flag directly using setter method. In Kotlin or is the replacement for the Java bitwise or |.

intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK

If you plan to use this regularly, create an Intent extension function

fun Intent.clearStack() {
    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

You can then directly call this function before starting the intent

intent.clearStack()

If you need the option to add additional flags in other situations, add an optional param to the extension function.

fun Intent.clearStack(additionalFlags: Int = 0) {
    flags = additionalFlags or Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

add to Manifest for your activity android:launchMode="singleTask"

You can use below method

    fun signOut(context: Context) {
        try {
                val intent = Intent(context, SplashActivity::class.java)
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK)
                context.startActivity(intent)
                (context as Activity).finishAffinity()
            }
        } catch (e: Exception) {
            LogUtils.logE("EXCEPTION", e)
        }

    }

Use this

Intent i1=new Intent(getApplicationContext(),StartUp_Page.class);
i1.setAction(Intent.ACTION_MAIN);
i1.addCategory(Intent.CATEGORY_HOME);
i1.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i1.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
i1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(i1);
finish();