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);
}

This should help you:

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.

I finally got it working. This way only a few apps are shown by the chooser (Google Drive, Dropbox, Root Explorer, and Solid Explorer). It's working fine with the two explorers but not with Google Drive and Dropbox (I guess because they cannot access the external storage). The other MIME type like "*/*" is also possible.

public void openFolder(){
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    Uri uri = Uri.parse(Environment.getExternalStorageDirectory().getPath()
	     +  File.separator + "myFolder" + File.separator);
    intent.setDataAndType(uri, "text/csv");
    startActivity(Intent.createChooser(intent, "Open folder"));
}

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()).

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.

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 - https://stackoverflow.com/questions/38200282/android-os-fileuriexposedexception-file-storage-emulated-0-test-txt-exposed

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

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

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

Will open files app home screen

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);

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());
  }
}
}

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.

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