[android] Android: How to open a specific folder via Intent and show its content in a file browser?

I thought this would be easy but as it turns out unfortunately it's not.

What I have:

I have a folder called "myFolder" on my external storage (not sd card because it's a Nexus 4, but that should not be the problem). The folder contains some *.csv files.

What I want:

I want to write a method which does the following: Show a variety of apps (file browsers) from which I can pick one (see picture). After I click on it, the selected file browser should start and show me the content of "myFolder". No more no less.

My question:

How exactly do I do that? I think I came quite close with the following code, but no matter what I do - and I'm certain that there must be something I didn't get right yet - it always opens only the main folder from the external storage.

public void openFolder()
{
File file = new File(Environment.getExternalStorageDirectory(),
    "myFolder");

Log.d("path", file.toString());

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setDataAndType(Uri.fromFile(file), "*/*");
startActivity(intent);
}

Today, you should be representing a folder using its content: URI as obtained from the Storage Access Framework, and opening it should be as simple as:

Intent i = new Intent(Intent.ACTION_VIEW, uri);
startActivity(i);

Alas, the Files app currently contains a bug that causes it to crash when you try this using the external storage provider. Folders from third party providers however can be displayed in this way.

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);

intent.setType("text/csv");

intent.addCategory(Intent.CATEGORY_OPENABLE);

try {
      startActivityForResult(Intent.createChooser(intent, "Select a File to Upload"), 0);

} catch (android.content.ActivityNotFoundException ex) {
  ex.printStackTrace();
}

then you just need to add the response

public void  onActivityResult(int requestCode, int resultCode, Intent data){

switch (requestCode) {
  case 0: {
     //what you want to do
    //file = new File(uri.getPath());
  }
}
}

Thread is old but I needed this kind of feature in my application and I found a way to do it so I decided to post it if it can help anyone in my situation.

As our device fleet is composed only by Samsung Galaxy Tab 2, I just had to find the file explorer's package name, give the right path and I succeed open my file explorer where I wanted to. I wish I could use Intent.CATEGORY_APP_FILES but it is only available in API 29.

  Intent intent = context.getPackageManager().getLaunchIntentForPackage("com.sec.android.app.myfiles");
  Uri uri = Uri.parse(rootPath);
  if (intent != null) {
      intent.setData(uri);
      startActivity(intent);
  }

As I said, it was easy for me because our clients have the same device but it may help others to find a workaround for their own situation.

this code will work with OI File Manager :

        File root = new File(Environment.getExternalStorageDirectory().getPath()
+ "/myFolder/");
        Uri uri = Uri.fromFile(root);

        Intent intent = new Intent();
        intent.setAction(android.content.Intent.ACTION_VIEW);
        intent.setData(uri);
        startActivityForResult(intent, 1);

you can get OI File manager here : http://www.openintents.org/en/filemanager

You seem close.

I would try to set the URI like this :

String folderPath = Environment.getExternalStorageDirectory()+"/pathTo/folder";

Intent intent = new Intent();  
intent.setAction(Intent.ACTION_GET_CONTENT);
Uri myUri = Uri.parse(folderPath);
intent.setDataAndType(myUri , "file/*");   
startActivity(intent);

But it's not so different from what you have tried. Tell us if it changes anything ?

Also make sure the targeted folder exists, and have a look on the resulting Uri object before to send it to the intent, it may not be what we are expected.

Intent chooser = new Intent(Intent.ACTION_GET_CONTENT);
Uri uri = Uri.parse(Environment.getDownloadCacheDirectory().getPath().toString());
chooser.addCategory(Intent.CATEGORY_OPENABLE);
chooser.setDataAndType(uri, "*/*");
// startActivity(chooser);
try {
startActivityForResult(chooser, SELECT_FILE);
}
catch (android.content.ActivityNotFoundException ex)
{
Toast.makeText(this, "Please install a File Manager.",
Toast.LENGTH_SHORT).show();
}

In code above, if setDataAndType is "*/*" a builtin file browser is opened to pick any file, if I set "text/plain" Dropbox is opened. I have Dropbox, Google Drive installed. If I uninstall Dropbox only "*/*" works to open file browser. This is Android 4.4.2. I can download contents from Dropbox and for Google Drive, by getContentResolver().openInputStream(data.getData()).

This should work:

Uri selectedUri = Uri.parse(Environment.getExternalStorageDirectory() + "/myFolder/");
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(selectedUri, "resource/folder");

if (intent.resolveActivityInfo(getPackageManager(), 0) != null)
{
    startActivity(intent);
}
else
{
    // if you reach this place, it means there is no any file 
    // explorer app installed on your device
}

Please, be sure that you have any file explorer app installed on your device.

EDIT: added a shantanu's recommendation from the comment.

LIBRARIES: You can also have a look at the following libraries https://android-arsenal.com/tag/35 if the current solution doesn't help you.

Here is my answer

private fun openFolder() {
    val location = "/storage/emulated/0/Download/";
    val intent = Intent(Intent.ACTION_VIEW)
    val myDir: Uri = FileProvider.getUriForFile(context, context.applicationContext.packageName + ".provider", File(location))
    intent.flags = Intent.FLAG_GRANT_READ_URI_PERMISSION
    intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT)
        intent.setDataAndType(myDir,  DocumentsContract.Document.MIME_TYPE_DIR)
    else  intent.setDataAndType(myDir,  "*/*")

    if (intent.resolveActivityInfo(context.packageManager, 0) != null)
    {
        context.startActivity(intent)
    }
    else
    {
        // if you reach this place, it means there is no any file
        // explorer app installed on your device
        CustomToast.toastIt(context,context.getString(R.string.there_is_no_file_explorer_app_present_text))
    }
}

Here why I used FileProvider - android.os.FileUriExposedException: file:///storage/emulated/0/test.txt exposed beyond app through Intent.getData()

I tested on this device
Devices: Samsung SM-G950F (dreamltexx), Os API Level: 28

File temp = File.createTempFile("preview", ".png" );
String fullfileName= temp.getAbsolutePath();
final String fileName = Uri.parse(fullfileName)
                    .getLastPathSegment();
final String filePath = fullfileName.
                     substring(0,fullfileName.lastIndexOf(File.separator));
Log.d("filePath", "filePath: " + filePath);

fullfileName:

/mnt/sdcard/Download_Manager_Farsi/preview.png

filePath:

/mnt/sdcard/Download_Manager_Farsi

Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(uri, DocumentsContract.Document.MIME_TYPE_DIR);
startActivity(intent);

Will open files app home screen