Android Java Upload File via WebView without FileChooser

Question

I need to write an Android application which is capable of loading a Website via a WebView. The Website contains an Input (Type=FILE)

<form action="...">
    <input type="file" name="myFile" value="" id="..."><
    <input type="submit" value="submit"><
</form>

When loading is done, the application should use a specific Image and upload it via a storage path:

String Path = "/storage/emulated/0/myimage.jpg"

I already tried to open a FileChooser-Dialog and that works, but I need a solution without the filechooser. The path of the "Path"-Variable should be used. I know that this would be a huge security leak, but is there maybe a solution for this? Maybe change die input-value via JavaScript? Maybe with a Library?

PS: Not meant to do anything illegal - the company app is generating profile images and they need to be uploaded via an existing unchangeable Input of type File.

Thanks in advance.

Mustansir · Accepted Answer · 2019-08-09T07:52:46.877

You can try this:

1) Get the URI of your file.

2) Trigger file chooser

3) Override onShowFileChooser inside WebChromeClient like this:

ValueCallback<Uri[]> mFilePathCallback;
@Override
 public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {

              if (mFilePathCallback != null) {
                    mFilePathCallback.onReceiveValue(null);
                }
                mFilePathCallback = filePathCallback;
                mFilePathCallback.onReceiveValue(myURI);
                mFilePathCallback = null;

                return true;

}

Here myURI is the URI of your file.

Make sure you have storage permission before trying this. – Mustansir Aug 09 '19 at 07:53 — Mustansir, Aug 09 '19 at 07:53

score 0 · Answer 2 · answered Aug 09 '19 at 07:39

Check my answer here. What you basically need to do is override WebChromeClient and its method openFileChooser.

class MyWebChromeClient extends WebChromeClient {
    // For 3.0+ Devices (Start)
    // onActivityResult attached before constructor
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }


    // For Lollipop 5.0+ Devices
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
        if (uploadMessage != null) {
            uploadMessage.onReceiveValue(null);
            uploadMessage = null;
        }

        uploadMessage = filePathCallback;

        Intent intent = fileChooserParams.createIntent();
        try {
            startActivityForResult(intent, REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e) {
            uploadMessage = null;
            Toast.makeText(WebLink.this, "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
            return false;
        }
        return true;
    }

    //For Android 4.1 only
    protected void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
        mUploadMessage = uploadMsg;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("image/*");
        startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    protected void openFileChooser(ValueCallback<Uri> uploadMsg) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }
}

Thanks for your answer, but that opens the FileChooser, am I right? - I need a solution to upload a file from a specific path, without opening a chooser. — Manuel Maurer, Aug 09 '19 at 07:42
@ManuelMaurer Yes, you're right. But you can customize it. and return the result in the same method using `uploadMessage.onReceiveValue` method without the intent to select file. — Rahul Khurana, Aug 09 '19 at 07:45

Android Java Upload File via WebView without FileChooser

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