Can I use it in java code ?

[exzant]

How ?

[AbedQa]

bottomBar.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelect(int i) { Log.d("",i + ""); } });

[brookmg]

smoothBottomBar.setOnItemSelectedListener(i -> {
    // i = the currently selected index
});

smoothBottomBar.setOnItemReselectedListener(i -> {
    // i = the currently reselected index
});

The above code can be used for setting the item selected and item reselected listeners. But to have this kind of simple expression you need to enable Java1.8 compile option.

go to your app.gradle file and add the following snippet inside the android object

android {
   ...

   compileOptions {
        sourceCompatibility = 1.8
        targetCompatibility = 1.8
    }
}

[sureshios]

i need in java

[1902shubh]

private NavController navController;
private SmoothBottomBar bottomNavigationView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bottomNavigationView = findViewById(R.id.bottomBar);
    navController = Navigation.findNavController(this, R.id.nav_host_fragment);
    NavigationUI.setupActionBarWithNavController(this, navController);

    setupSmoothBottomBar();

}

private void setupSmoothBottomBar() {
    PopupMenu popupMenu = new PopupMenu(this, null);
    popupMenu.inflate(R.menu.bottom_nav);
    Menu menu  = popupMenu.getMenu();
    bottomNavigationView.setupWithNavController(menu, navController);
}

@Override
public boolean onSupportNavigateUp() {
    return navController.navigateUp() || super.onSupportNavigateUp();
}