title: BottomNavigationView - How to get selected menu item?
body: <p>I used BottomNavigationView to switch fragments. How to get currently selected menu item, to prevent reopening fragment ? </p>
  
  <pre><code>        BottomNavigationView bottomNavigationView = (BottomNavigationView)
                  findViewById(R.id.bottom_navigation);
  
          bottomNavigationView.setOnNavigationItemSelectedListener(
                  new BottomNavigationView.OnNavigationItemSelectedListener() {
                      @Override
                      public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                          switch (item.getItemId()) {
                              case R.id.action_1:
                                  // open fragment 1
                                  break;
                              case R.id.action_2:
                                  // open fragment 2
                                  break;
                              case R.id.action_3:
                                  // open fragment 3
                                  break;
                          }
                          return false;
                      }
                  });
      }
  </code></pre>