Java：发送带有附件的电子邮件：无法发送附件

Question

I'm working on creating an app but I'm having a problem. After I've inserted some data in a file named "message.txt", I'm not able to send this file by e-mail because my smartphone says "impossible to send the attachment". How can I resolve this problem?

This is the code:

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    String address = ...
    byte[] messagetosend = ...
    String filename = "message.txt";
    File file = new File(getExternalFilesDir(null), filename);
    FileOutputStream outputstream;
    try {
        outputstream = openFileOutput(filename,MODE_WORLD_READABLE);
        outputstream.write(messagetosend);
        outputstream.flush();
        outputstream.getFD().sync();
        outputstream.close();
    } catch (Exception e1) {
        e1.printStackTrace();
    }
    Intent sendIntent = new Intent();
    sendIntent.setAction(Intent.ACTION_SEND);
    sendIntent.putExtra(Intent.EXTRA_EMAIL, new String[]{address});
    sendIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(file));
    sendIntent.setType("*/*");
    startActivity(Intent.createChooser(sendIntent,"Send with..."));
    }

Answer 1

Third party apps have no rights to access that file. Use FileProvider to serve it, or copy the file to external storage instead of internal storage .

Answer 2

If you have saved the file as being private to the app, the app can see if fine but the external email client will not be able to see it. You'll need to write it out to external storage, or make it public. visit this link and visit this you will understand about access levels.

OR try to send email with JavaMail here is solved , here is too