Create and Share a File from Internal Storage

Question

My goal is to create a XML file on internal storage and then send it through the share Intent.

I'm able to create a XML file using this code

FileOutputStream outputStream = context.openFileOutput(fileName, Context.MODE_WORLD_READABLE); PrintStream printStream = new PrintStream(outputStream); String xml = this.writeXml(); // get XML here printStream.println(xml); printStream.close(); 

I'm stuck trying to retrieve a Uri to the output file in order to share it. I first tried to access the file by converting the file to a Uri

File outFile = context.getFileStreamPath(fileName); return Uri.fromFile(outFile); 

This returns file:///data/data/com.my.package/files/myfile.xml but I cannot appear to attach this to an email, upload, etc.

If I manually check the file length, it's proper and shows there is a reasonable file size.

Next I created a content provider and tried to reference the file and it isn't a valid handle to the file. The ContentProvider doesn't ever seem to be called a any point.

Uri uri = Uri.parse("content://" + CachedFileProvider.AUTHORITY + "/" + fileName); return uri; 

This returns content://com.my.package.provider/myfile.xml but I check the file and it's zero length.

How do I access files properly? Do I need to create the file with the content provider? If so, how?

Update

Here is the code I'm using to share. If I select Gmail, it does show as an attachment but when I send it gives an error Couldn't show attachment and the email that arrives has no attachment.

public void onClick(View view) {     Log.d(TAG, "onClick " + view.getId());      switch (view.getId()) {         case R.id.share_cancel:             setResult(RESULT_CANCELED, getIntent());             finish();             break;          case R.id.share_share:              MyXml xml = new MyXml();             Uri uri;             try {                 uri = xml.writeXmlToFile(getApplicationContext(), "myfile.xml");                 //uri is  "file:///data/data/com.my.package/files/myfile.xml"                 Log.d(TAG, "Share URI: " + uri.toString() + " path: " + uri.getPath());                  File f = new File(uri.getPath());                 Log.d(TAG, "File length: " + f.length());                 // shows a valid file size                  Intent shareIntent = new Intent();                 shareIntent.setAction(Intent.ACTION_SEND);                 shareIntent.putExtra(Intent.EXTRA_STREAM, uri);                 shareIntent.setType("text/plain");                 startActivity(Intent.createChooser(shareIntent, "Share"));             } catch (FileNotFoundException e) {                 e.printStackTrace();             }              break;     } } 

I noticed that there is an Exception thrown here from inside createChooser(...), but I can't figure out why it's thrown.

E/ActivityThread(572): Activity com.android.internal.app.ChooserActivity has leaked IntentReceiver com.android.internal.app.ResolverActivity$1@4148d658 that was originally registered here. Are you missing a call to unregisterReceiver()?

I've researched this error and can't find anything obvious. Both of these links suggest that I need to unregister a receiver.

• ChooserActivity has leaked IntentReceiver
• Why does Intent.createChooser() need a BroadcastReceiver and how to implement?

I have a receiver setup, but it's for an AlarmManager that is set elsewhere and doesn't require the app to register / unregister.

Code for openFile(...)

In case it's needed, here is the content provider I've created.

public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {     String fileLocation = getContext().getCacheDir() + "/" + uri.getLastPathSegment();      ParcelFileDescriptor pfd = ParcelFileDescriptor.open(new File(fileLocation), ParcelFileDescriptor.MODE_READ_ONLY);     return pfd; } 

Answer 1

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);     } }