Create and Share a File from Internal Storage

Create and Share a File from Internal Storage

It is possible to expose a file stored in your apps private directory via a ContentProvider. Here is some example code I made showing how to create a content provider that can do this.

Manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.providertest"
  android:versionCode="1"
  android:versionName="1.0">

  <uses-sdk android:minSdkVersion="11" android:targetSdkVersion="15" />

  <application android:label="@string/app_name"
    android:icon="@drawable/ic_launcher"
    android:theme="@style/AppTheme">

    <activity
        android:name=".MainActivity"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <provider
        android:name="MyProvider"
        android:authorities="com.example.prov"
        android:exported="true"
        />        
  </application>
</manifest>

In your ContentProvider override openFile to return the ParcelFileDescriptor

@Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {       
     File cacheDir = getContext().getCacheDir();
     File privateFile = new File(cacheDir, "file.xml");

     return ParcelFileDescriptor.open(privateFile, ParcelFileDescriptor.MODE_READ_ONLY);
}

Make sure you have copied your xml file to the cache directory

    private void copyFileToInternal() {
    try {
        InputStream is = getAssets().open("file.xml");

        File cacheDir = getCacheDir();
        File outFile = new File(cacheDir, "file.xml");

        OutputStream os = new FileOutputStream(outFile.getAbsolutePath());

        byte[] buff = new byte[1024];
        int len;
        while ((len = is.read(buff)) > 0) {
            os.write(buff, 0, len);
        }
        os.flush();
        os.close();
        is.close();

    } catch (IOException e) {
        e.printStackTrace(); // TODO: should close streams properly here
    }
}

Now any other apps should be able to get an InputStream for your private file by using the content uri (content://com.example.prov/myfile.xml)

For a simple test, call the content provider from a seperate app similar to the following

    private class MyTask extends AsyncTask<String, Integer, String> {

    @Override
    protected String doInBackground(String... params) {

        Uri uri = Uri.parse("content://com.example.prov/myfile.xml");
        InputStream is = null;          
        StringBuilder result = new StringBuilder();
        try {
            is = getApplicationContext().getContentResolver().openInputStream(uri);
            BufferedReader r = new BufferedReader(new InputStreamReader(is));
            String line;
            while ((line = r.readLine()) != null) {
                result.append(line);
            }               
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try { if (is != null) is.close(); } catch (IOException e) { }
        }

        return result.toString();
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(CallerActivity.this, result, Toast.LENGTH_LONG).show();
        super.onPostExecute(result);
    }
}

Android Intent.ACTION_SEND from Internal Storage with Content Provider

Thanks for pskink. FileProvider worked perfectly:

Gradle dependency:

compile 'com.android.support:support-v4:25.0.0'

Manifest:

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.package.example"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>

file_paths.xml in XML folder:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <cache-path name="cache" path="/" />
</paths>

Sharing Intent:

    File file = new File(context.getCacheDir(), filename);

    Uri contentUri = FileProvider.getUriForFile(context, "com.package.example", file);

    Intent shareIntent = new Intent(Intent.ACTION_SEND);
    shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri);
    shareIntent.setType("text/plain");
    context.startActivity(Intent.createChooser(shareIntent, context.getResources().getText(R.string.chooser)));

Share text file via Intent from internal storage

I found one of solution for this problem. How @CommonsWare suggested I used a FileProvider. I follow this example. But in provider_paths.xml I put this code, because I use a internal storage.

<Paths xmlns:android="http://schemas.android.com/apk/res/android">
    <files-path name="files" path="."/>
</Paths>

Then in activity I send a file via intent like this:

       Uri path = FileProvider.getUriForFile(this,"same_authoritory_which_was_in_manifest", new File(FILE_TO_SAVE.getPath()));
       Intent i = new Intent(Intent.ACTION_SEND);
       i.putExtra(Intent.EXTRA_TEXT, "Test");
       i.putExtra(Intent.EXTRA_STREAM, path);
       i.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
       i.setType("plain/*");
       startActivity(i);

How could I create a file in the Internal Storage Directory?

After a while later I found the answer to this question.

public void createDirectory() {
    File file = new File(Environment.getExternalStorageDirectory(), "/test");
    if (!file.exists()) {
        file.mkdirs();
        Log.w("DEBUG", "Created default directory.");

    }
}

This is how you create it code wise. The reason it wasn't creating was due to Samsungs weird permissions.

Make sure you have the storage permission enabled in Settings -> Apps -> App Name -> Permissions. I needed to turn it on so it would create the folder.

Writing to file in Documents folder in internal storage

File file = new File(Environment.DIRECTORY_DOCUMENTS, "myFile.txt");

File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS), "myFile.txt");

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