Android Bottom navigation Example Java

1/  Create A New Project  and Use Material Bottom Navigation 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomnav"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="#AEEBE9E9"
        app:menu="@menu/bottom_nav" />     // It's bottom nav menu


</RelativeLayout>

2/  Create A Menu Directory inside drawable and get an XML

3/Get the Required items in this xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/home"
        android:title="Home"
        android:icon="@drawable/baseline_home_24"
        
        />

    <item
        android:id="@+id/list"
        android:title="Home"
        android:icon="@drawable/baseline_list_alt_24"
        />

    <item
        android:id="@+id/menu"
        android:title="Home"
        android:icon="@drawable/baseline_home_24"
        />


</menu>

4/  Go to java Activity

1.  Find navigation view .
2.  Create  Onclick Listener
3.  If Statement  and find navigation item id 
4. you can send new Activity or Fragment
    

package com.example.bottomnavigation;

import android.os.Bundle;
import android.view.MenuItem;

import androidx.activity.EdgeToEdge;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.GravityCompat;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.android.material.navigation.NavigationBarView;

public class MainActivity extends AppCompatActivity {
    
    BottomNavigationView bottomnav;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        bottomnav= findViewById(R.id.bottomnav);



        bottomnav.setOnItemSelectedListener(new NavigationBarView.OnItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {

                if (item.getItemId()==R.id.home){

                } else if (item.getItemId()==R.id.list) {

                }else if (item.getItemId()==R.id.menu) {
                    
                }

                return true;
            }
        });

    }
}

5/  Now Run App and Output