public class MainActivity extends AppCompatActivity implements SwipeRefreshLayout.OnRefreshListener {    private  String link="site.com/?utm_source=mobil&utm_medium=uygulama";    private  SwipeRefreshLayout sw;  //swipe layout    public  WebView w;  //web view    private AdView mAdView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mAdView = findViewById(R.id.adView);        AdRequest adRequest = new AdRequest.Builder().build();        mAdView.loadAd(adRequest);        sw=(SwipeRefreshLayout) findViewById(R.id.sw);         w = (WebView) findViewById(R.id.w);        sw.setOnRefreshListener(this);        w.getSettings().setJavaScriptEnabled(true);        w.setWebViewClient( new WebViewClient());        w.loadUrl(link);    }    @Override    public void onRefresh() {        w.reload();        sw.setRefreshing(false);    }}