нет всплывающего окна для веб-просмотра Android для загрузки файлов или открытия камеры

Попробуйте этот код:

public class MainActivity extends Activity {

private RelativeLayout mLayout;
private ProgressBar progressBar;
private WebView webView;
String loadUrl;

private static final int INPUT_FILE_REQUEST_CODE = 1;
private static final int FILECHOOSER_RESULTCODE = 1;
private static final String TAG = MainActivity.class.getSimpleName();
private WebSettings webSettings;
private ValueCallback<Uri> mUploadMessage;
private Uri mCapturedImageURI = null;
private ValueCallback<Uri[]> mFilePathCallback;
private String mCameraPhotoPath;
ValueCallback<Uri[]> chooserPathUri;

public static final int REQUEST_ID_MULTIPLE_PERMISSIONS = 1;

WebView chooserWV;
WebChromeClient.FileChooserParams chooserParams;

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

    loadUrl = "https:google.com";

    mLayout = (RelativeLayout) findViewById(R.id.activity_main);
    progressBar = (ProgressBar)findViewById(R.id.indicator);
    webView = (WebView) findViewById(R.id.webView);
    webSettings = webView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    webSettings.setLoadWithOverviewMode(true);
    webSettings.setDomStorageEnabled(true);
    webSettings.setUseWideViewPort(true);
    webSettings.setLoadWithOverviewMode(true);
    webSettings.setAllowFileAccess(true);
    if (Build.VERSION.SDK_INT >= 19) {
        webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
    }
    else if(Build.VERSION.SDK_INT >=11 && Build.VERSION.SDK_INT < 19) {
        webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
    }
    webView.setWebChromeClient(new ChromeClient());
    webView.loadUrl(loadUrl); //change with your website

    this.webView.setWebViewClient(new WebViewClient(){
        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            progressBar.setVisibility(View.INVISIBLE);

        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
            progressBar.setVisibility(View.VISIBLE);
        }

        @SuppressWarnings("deprecation")
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return handleUrl(url);
        }

        @TargetApi(Build.VERSION_CODES.N)
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
            final Uri uri = request.getUrl();
            return handleUrl(request.getUrl().toString());
        }
    });
}

public boolean handleUrl(String url){

    if (url.startsWith("geo:") || url.startsWith("mailto:") || url.startsWith("tel:") || url.startsWith("sms:")) {
        Intent searchAddress = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
        startActivity(searchAddress);
    }else
        webView.loadUrl(url);
    return true;
}

private  boolean checkAndRequestPermissions() {
    int permissionCamera = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
    int permissionStorage = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
    List<String> listPermissionsNeeded = new ArrayList<>();
    if (permissionStorage != PackageManager.PERMISSION_GRANTED) {
        listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }
    if (permissionCamera != PackageManager.PERMISSION_GRANTED) {
        listPermissionsNeeded.add(Manifest.permission.CAMERA);
    }
    if (!listPermissionsNeeded.isEmpty()) {
        ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]),REQUEST_ID_MULTIPLE_PERMISSIONS);
        Log.e(TAG, "Returned falseeeee-------");
        return false;
    }
    Log.d(TAG, "Permission returned trueeeee-------");
    return true;

}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    Log.d(TAG, "Permission callback called-------");
    switch (requestCode) {
        case REQUEST_ID_MULTIPLE_PERMISSIONS: {

            Map<String, Integer> perms = new HashMap<>();
            // Initialize the map with both permissions
            perms.put(Manifest.permission.CAMERA, PackageManager.PERMISSION_GRANTED);
            perms.put(Manifest.permission.WRITE_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
            // Fill with actual results from user
            if (grantResults.length > 0) {
                for (int i = 0; i < permissions.length; i++)
                    perms.put(permissions[i], grantResults[i]);
                // Check for both permissions
                if (perms.get(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
                    Log.d(TAG, "camera & Storage permission granted");
                    Toast.makeText(this, "Permissions granted! Try now.", Toast.LENGTH_SHORT).show();
                    //chromClt.openChooser(chooserWV, chooserPathUri, chooserParams);
                    // process the normal flow
                    //else any one or both the permissions are not granted
                } else {
                    Log.d(TAG, "Some permissions are not granted ask again ");
                    //permission is denied (this is the first time, when "never ask again" is not checked) so ask again explaining the usage of permission
                    // shouldShowRequestPermissionRationale will return true
                    //show the dialog or snackbar saying its necessary and try again otherwise proceed with setup.
                    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA) || ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                        showDialogOK("Camera and Storage Permission required for this app",
                                new DialogInterface.OnClickListener() {
                                    @Override
                                    public void onClick(DialogInterface dialog, int which) {
                                        switch (which) {
                                            case DialogInterface.BUTTON_POSITIVE:
                                                checkAndRequestPermissions();
                                                break;
                                            case DialogInterface.BUTTON_NEGATIVE:
                                                // proceed with logic by disabling the related features or quit the app.
                                                break;
                                        }
                                    }
                                });
                    }
                    //permission is denied (and never ask again is  checked)
                    //shouldShowRequestPermissionRationale will return false
                    else {
                        Toast.makeText(this, "Go to settings and enable permissions", Toast.LENGTH_LONG).show();
                        //                            //proceed with logic by disabling the related features or quit the app.
                    }
                }
            }
            break;
        }
    }

}

private void showDialogOK(String message, DialogInterface.OnClickListener okListener) {
    new AlertDialog.Builder(this)
            .setMessage(message)
            .setPositiveButton("OK", okListener)
            .setNegativeButton("Cancel", okListener)
            .create()
            .show();
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (requestCode != INPUT_FILE_REQUEST_CODE || mFilePathCallback == null) {
            super.onActivityResult(requestCode, resultCode, data);
            return;
        }
        Uri[] results = null;
        // Check that the response is a good one
        if (resultCode == Activity.RESULT_OK) {
            if (data == null) {
                // If there is not data, then we may have taken a photo
                if (mCameraPhotoPath != null) {
                    results = new Uri[]{Uri.parse(mCameraPhotoPath)};
                }
            } else {
                String dataString = data.getDataString();
                if (dataString != null) {
                    results = new Uri[]{Uri.parse(dataString)};
                }else {
                    if (Build.VERSION.SDK_INT >= 16) {
                        if (data.getClipData() != null) {
                            final int numSelectedFiles = data.getClipData().getItemCount();

                            results = new Uri[numSelectedFiles];

                            for (int i = 0; i < numSelectedFiles; i++) {
                                results[i] = data.getClipData().getItemAt(i).getUri();
                            }
                        }
                    }
                }
            }
        }
        mFilePathCallback.onReceiveValue(results);
        mFilePathCallback = null;
    } else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
        if (requestCode != FILECHOOSER_RESULTCODE || mUploadMessage == null) {
            super.onActivityResult(requestCode, resultCode, data);
            return;
        }
        if (requestCode == FILECHOOSER_RESULTCODE) {
            if (null == this.mUploadMessage) {
                return;
            }
            Uri result = null;
            try {
                if (resultCode != RESULT_OK) {
                    result = null;
                } else {
                    // retrieve from the private variable if the intent is null
                    result = data == null ? mCapturedImageURI : data.getData();
                }
            } catch (Exception e) {
                Toast.makeText(getApplicationContext(), "activity :" + e,
                        Toast.LENGTH_LONG).show();
            }
            mUploadMessage.onReceiveValue(result);
            mUploadMessage = null;
        }
    }
    return;
}

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
    File imageFile = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir      /* directory */
    );
    return imageFile;
}

public class ChromeClient extends WebChromeClient {

    public void onGeolocationPermissionsShowPrompt(String origin, GeolocationPermissions.Callback callback) {
        // callback.invoke(String origin, boolean allow, boolean remember);
        Log.e(TAG, "onGeolocationPermissionsShowPrompt: " );
        callback.invoke(origin, true, false);
    }

    // For Android 5.0
    public boolean onShowFileChooser(WebView view, ValueCallback<Uri[]> filePath, WebChromeClient.FileChooserParams fileChooserParams) {

        chooserWV = view;
        chooserPathUri = filePath;
        chooserParams = fileChooserParams;

        if(checkAndRequestPermissions()){
            openChooser(chooserWV, chooserPathUri, chooserParams);

            return true;
        }else {
            return false;
        }

    }


    public void openChooser(WebView view, ValueCallback<Uri[]> filePath, WebChromeClient.FileChooserParams fileChooserParams){

        // Double check that we don't have any existing callbacks
        if (mFilePathCallback != null) {
            mFilePathCallback.onReceiveValue(null);
        }
        mFilePathCallback = filePath;
        Intent takePictureIntent;

        takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            // Create the File where the photo should go
            File photoFile = null;
            try {
                photoFile = createImageFile();
                takePictureIntent.putExtra("PhotoPath", mCameraPhotoPath);
            } catch (IOException ex) {
                // Error occurred while creating the File
                Log.e(TAG, "Unable to create Image File", ex);
            }
            // Continue only if the File was successfully created
            if (photoFile != null) {
                mCameraPhotoPath = "file:" + photoFile.getAbsolutePath();
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
            } else {
                takePictureIntent = null;
            }
        }
        Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
        contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
        if (Build.VERSION.SDK_INT >= 18) {
            contentSelectionIntent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
        }
        contentSelectionIntent.setType("*/*");
        Intent[] intentArray;
        if (takePictureIntent != null) {
            intentArray = new Intent[]{takePictureIntent};
        } else {
            intentArray = new Intent[0];
        }
        Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
        chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
        chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
        startActivityForResult(chooserIntent, INPUT_FILE_REQUEST_CODE);
    }

    // openFileChooser for Android 3.0+
    public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {

        mUploadMessage = uploadMsg;
        // Create AndroidExampleFolder at sdcard
        // Create AndroidExampleFolder at sdcard
        File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES)
                , "AndroidExampleFolder");
        if (!imageStorageDir.exists()) {
            // Create AndroidExampleFolder at sdcard
            imageStorageDir.mkdirs();
        }
        // Create camera captured image file path and name
        File file = new File(
                imageStorageDir + File.separator + "IMG_"
                        + String.valueOf(System.currentTimeMillis())
                        + ".jpg");
        mCapturedImageURI = Uri.fromFile(file);
        // Camera capture image intent
        final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        // Create file chooser intent
        Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
        // Set camera intent to file chooser
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[]{captureIntent});
        // On select image call onActivityResult method of activity

        chooserIntent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
        startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
    }

    // openFileChooser for Android < 3.0
    public void openFileChooser(ValueCallback<Uri> uploadMsg) {
        openFileChooser(uploadMsg, "");
    }

    //openFileChooser for other Android versions
    public void openFileChooser(ValueCallback<Uri> uploadMsg,
                                String acceptType,
                                String capture) {
        openFileChooser(uploadMsg, acceptType);
    }

}



@SuppressLint("NewApi")
@Override
protected void onResume() {
    super.onResume();
    webView.onResume();
    // ...
}

@SuppressLint("NewApi")
@Override
protected void onPause() {
    webView.onPause();
    // ...
    super.onPause();
}

int mExit = 0;

@Override
public void onBackPressed() {
    if(webView.canGoBack()) {
        webView.goBack();
    } else {
        super.onBackPressed();
    }

}

Не забудьте добавить разрешения в манифест:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.CAMERA"/>