Enable File Upload in Android Webview

Android WebView is used to display web page in android. The web page can be loaded from same application or URL. It is used to display online content in android activity. You can also insert text in that page which is shown using web view. But WebView in Android can not open the file selection box directly.
In 5.0 Lollipop, Google added an official method, WebChromeClient.onShowFileChooser. They even provide a way to automatically generate the file chooser intent so that it uses the input accept mime types.

Here is a brief solution-
1. Receive notification that WebView opens the file selector
2. After receiving the notification, open the file selector and wait for the user to select the file to upload.
3. Get the Uri of the file selected by the user in onActivityResult
4. Then pass Uri to Html5

First of all, You need to give 3 permission in AndoidManifest.xml. Those are given below:

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

After that, you need to write code in MainActivity.java file. You need to take some global variable for opening file chooser with camera option, see below code:

private static final String TAG = MainActivity.class.getSimpleName();

    public static final int INPUT_FILE_REQUEST_CODE = 1;
  private ValueCallback mFilePathCallback;
  private String mCameraPhotoPath;

WebView must support JS interaction, so open JS interaction

mWebView.getSettings().setJavaScriptEnabled(true);

After that, you need to write code for showing "file chooser". When H5 invokes the Api for uploading files, WebView calls the onShowFileChooser methods to inform us that all we need to do at this time is to rewrite this method.
It should be noted that this method calls back different row parameter methods on different Apis.

webView.setWebChromeClient(new WebChromeClient() {
        
       
 public boolean onShowFileChooser(
                WebView webView, ValueCallback filePathCallback,
                WebChromeClient.FileChooserParams fileChooserParams) {
            if (mFilePathCallback != null) {
                mFilePathCallback.onReceiveValue(null);
            }
            mFilePathCallback = filePathCallback;

            Intent 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) {//"file:" +
                    mCameraPhotoPath =  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);
            contentSelectionIntent.setType("image/*");

            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);

            return true;
        }
    });

    webView.loadUrl(webViewUrl);
}

When the user has selected the file, the onActivityResult method is called, and we rewrite and wait for the callback.

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    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)};

                try {

                    Uri uri=Uri.fromFile(new File(mCameraPhotoPath));

                        String path = getPathFromUri(uri);
                        File file1 = compressImage(path);
                        results = new Uri[]{getImageContentUri(this, file1)};

                    mFilePathCallback.onReceiveValue(results);
                } catch (Exception e) {
                    FirebaseCrashlytics.getInstance().recordException(e);
                    e.printStackTrace();
                }

            }
        } else {
            String dataString = data.getDataString();
            if (dataString != null) {
                results = new Uri[]{Uri.parse(dataString)};
                Uri uri = Uri.parse(dataString);
                File sourceFile = new File(getPathFromGooglePhotosUri(uri));
                String path = sourceFile.getPath();
                File file1 = compressImage(path);
                results = new Uri[]{getImageContentUri(this, file1)};
                mFilePathCallback.onReceiveValue(results);
            }
        }
    }

    mFilePathCallback = null;
}