Android WebView

package com.webviewexample;

import android.Manifest;
import android.annotation.SuppressLint;
import android.app.DownloadManager;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.webkit.CookieManager;
import android.webkit.URLUtil;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;


public class MyWebView extends AppCompatActivity {
  // Declare our web view.
  private WebView webview;

  // We can pass URLs from any other class to this string.
  static String url;

  // Optional progress bar for page loading progress.
  private ProgressBar progress;

  // A request code for our storage write request.
  private static final int WRITE_STORAGE = 1;

  @SuppressLint("SetJavaScriptEnabled")
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_webview);

    // Optional progress bar for page loading progress.
    progress = findViewById(R.id.progressBar);

    // Attach our web view to our layout.
    webview = findViewById(R.id.webView);
    // Needed to interact with elements on most web pages.
    webview.getSettings().setJavaScriptEnabled(true);
    // This enables pinch to zoom.
    webview.getSettings().setBuiltInZoomControls(true);
    // Do not display the zoom controls on the screen.
    webview.getSettings().setDisplayZoomControls(false);
    // Loads a page to fit in the screen (zoomed out).
    webview.getSettings().setLoadWithOverviewMode(true);
    // Do not constrain the viewport to the web view dimensions.
    webview.getSettings().setUseWideViewPort(true);
    // Allow website user settings to be saved and retrieved.
    webview.getSettings().setDomStorageEnabled(true);
    // Attach our web view to our WebViewClient.
    webview.setWebViewClient(new MyWebViewClient());
    // We call our url string variable to load.
    webview.loadUrl(url);

    // Adds a DownloadListener to our web view. This allows us to click on
    // download links and have items download to our downloads directory.
    webview.setDownloadListener((url, userAgent, contentDisposition, mimetype, contentLength) -> {
      String fileName = URLUtil.guessFileName(url, contentDisposition, null);
      String cookie = CookieManager.getInstance().getCookie(url);
      DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
      DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
      request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
      request.setAllowedOverRoaming(false);
      request.allowScanningByMediaScanner();
      request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
      request.addRequestHeader("Cookie", cookie);
      request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
      // Check for storage write permission before attempting to download.
      if (getPermission() && dm != null) {
        dm.enqueue(request);
      }
    });

  }

  // Check if storage write permission has been granted. If not, request it.
  private boolean getPermission() {
    if (Build.VERSION.SDK_INT >= 23) {
      if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
        // True if permission granted exists.
        return true;
      } else {
        // We ask for storage write permission if it doesn't exist.
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, WRITE_STORAGE);
        return false;
      }
    } else {
      // True for SDK < 23
      return true;
    }
  }

  // Check if user granted or denied storage write permission when requested and
  // run code for either situation. This method is optional, but useful.
  @Override
  public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == WRITE_STORAGE) {
      if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        Toast.makeText(getApplicationContext(), "Permission Granted. Try download again.", Toast.LENGTH_LONG).show();
      } else {
        Toast.makeText(getApplicationContext(), "Permission Denied! Cannot Download.", Toast.LENGTH_LONG).show();
      }
    }
  }

  // Attach our web view to our WebViewClient.
  private class MyWebViewClient extends WebViewClient {
    // This method makes sure that any links we click will open within
    // our app instead of launching in the default web browser.
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
      return super.shouldOverrideUrlLoading(view, url);
    }

    // Since this method is called every time a new page starts to load, it's
    // perfect to run our Progress Bar.
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
      progress.setVisibility(View.VISIBLE);
      super.onPageStarted(view, url, favicon);
    }

    // Called whenever a page has finished loading. Here we can end our
    // page loading progress bar and take it out of view.
    @Override
    public void onPageFinished(WebView view, String url) {
      progress.setVisibility(View.GONE);
      super.onPageFinished(view, url);
    }

  }

  // If we have clicked through multiple pages, this allows the back button
  // to take us back through each page.
  @Override
  public void onBackPressed() {
    if (webview.canGoBack()) {
      webview.goBack();
    } else {
      super.onBackPressed();
    }
  }
}

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

  <WebView
    android:id="@+id/webView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

  <ProgressBar
      android:id="@+id/progressBar"
      style="?android:attr/progressBarStyleHorizontal"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:indeterminateTint="?attr/colorAccent"
      android:indeterminate="true" />
</RelativeLayout>

package com.webviewexample;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;

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

    // This button will pass the Google website url to MyWebView.class
    Button gbtn = findViewById(R.id.googleButton);
    gbtn.setOnClickListener(view -> {
      MyWebView.url = "https://www.google.com/";
      Intent intent = new Intent(MainActivity.this, MyWebView.class);
      startActivity(intent);
    });

    // This button will pass the techStop website url to MyWebView.class
    Button tsbtn = findViewById(R.id.tsButton);
    tsbtn.setOnClickListener(view -> {
      MyWebView.url = "https://techstop.github.io/";
      Intent intent = new Intent(MainActivity.this, MyWebView.class);
      startActivity(intent);
    });
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:gravity="center"
  android:orientation="vertical"
  tools:context=".MainActivity">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/googleButton"
    android:text="@string/google" />

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/tsButton"
    android:text="@string/tech_Stop" />
</LinearLayout>

<resources>
  <string name="app_name">WebView Example</string>
  <string name="google">GOOGLE</string>
  <string name="tech_Stop">techStop</string>
</resources>

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

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
    <uses-permission android:name="android.permission.ACCESS_DOWNLOAD_MANAGER" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MyWebView" />
    </application>
</manifest>