JAVA

exit app android

ActivityName.this.finish();
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(0);

Exit program Android

public void onBackPressed() {
  moveTaskToBack(true);
  android.os.Process.killProcess(android.os.Process.myPid());
  System.exit(1);
}

exit app android

this.finishAffinity();