uses permissions required
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission android:name="android.permission.INTERNET" />
use xml file for webview
for show any view
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <WebView
        android:id="@+id/webView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <LinearLayout
        android:id="@+id/linNtWkOff"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:visibility="visible"
        android:gravity="center_vertical"
        android:orientation="vertical">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="300dp"
            android:src="@drawable/img_ntwk_conn"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="14sp"
            android:gravity="center_horizontal"
            android:textColor="@color/black"
            android:text="Internet Connection Unavailable"/>
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
i have used webView using network check in baseActivity
//There are following parameters:
    public class MainActivity extends BaseActivity {
    private WebView mWebView;
    LinearLayout linNtWkOff;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        linNtWkOff = findViewById(R.id.linNtWkOff);
        mWebView = (WebView) findViewById(R.id.webView);
    }
    @Override
    protected void onResume() {
        super.onResume();
        if (checkInternetConnection()){
            setNetWorkON();
        }else {
            setNetWorkOFF();
        }
        mWebView.setWebViewClient(new MyBrowser());
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setLoadsImagesAutomatically(true);
        mWebView.loadUrl("-----write your url------");
    }
    private class MyBrowser extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_BACK:
                    if (mWebView.canGoBack()) {
                        mWebView.goBack();
                    } else {
                        finish();
                    }
                    return true;
            }
        }
        return super.onKeyDown(keyCode, event);
    }
    public void setNetWorkON(){
        linNtWkOff.setVisibility(View.GONE);
        mWebView.setVisibility(View.VISIBLE);
    }
    public void setNetWorkOFF(){
        linNtWkOff.setVisibility(View.VISIBLE);
        mWebView.setVisibility(View.GONE);
    }
    private boolean checkInternetConnection() {
        ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo ni = manager.getActiveNetworkInfo();
        boolean isConnected;
        if (ni != null && ni.getState() == NetworkInfo.State.CONNECTED) {
            isConnected =true;
        } else {
            isConnected= false;
        }
        return isConnected;
    }
}
BaseActivity use for newwork connection check
public class BaseActivity extends AppCompatActivity {
    private static final int WIFI_ENABLE_REQUEST = 0x1006;
    private BroadcastReceiver mNetworkDetectReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            checkInternetConnection();
        }
    };
    private AlertDialog mInternetDialog;
    private boolean isConnected;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        isConnected = false;
        registerReceiver(mNetworkDetectReceiver, new IntentFilter(android.net.ConnectivityManager.CONNECTIVITY_ACTION));
    }
    @Override
    protected void onDestroy() {
        unregisterReceiver(mNetworkDetectReceiver);
        super.onDestroy();
    }
    private void checkInternetConnection() {
        ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo ni = manager.getActiveNetworkInfo();
        if (ni != null && ni.getState() == NetworkInfo.State.CONNECTED) {
            isConnected =true;
            //showNoConnectionSnackBar("Connected", isConnected, 1500);
            onResume();
        } else {
            isConnected= false;
            //showNoConnectionSnackBar("No active Internet connection found.", isConnected,10000);
            onResume();
        }
    }
    private  void showNoConnectionSnackBar(String message, boolean isConnected, int duration) {
        Snackbar snackbar = Snackbar.make(findViewById(android.R.id.content),
                message, duration);
        View sbView = snackbar.getView();
        TextView textView = (TextView) sbView
                .findViewById(R.id.snackbar_text);
        textView.setTextColor(ContextCompat.getColor(this, android.R.color.white));
        if (isConnected){
            sbView.setBackgroundColor(getResources().getColor(R.color.purple_500));
        }else{
            sbView.setBackgroundColor(getResources().getColor(R.color.purple_500));
            snackbar.setAction("Turn On", new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent internetOptionsIntent = new Intent(android.provider.Settings.ACTION_WIFI_SETTINGS);
                    startActivityForResult(internetOptionsIntent, WIFI_ENABLE_REQUEST);
                }
            });
            snackbar.setActionTextColor(getResources().getColor(R.color.purple_500));
        }
        snackbar.show();
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == WIFI_ENABLE_REQUEST) {
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}