อยากทราบวิธีการ Attachment ไฟล์รูปภาพโดยใช้ JavaMail API ครับ ไม่ทราบพี่ๆคนไหนเคยทำบ้างครับ

package com.example.rattapongt.androidsmtp;


import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    //Declaring EditText
    private EditText editTextEmail;
    private EditText editTextSubject;
    private EditText editTextMessage;

    //Send button
    private Button buttonSend, btnImageChooser;

    private Bitmap bitmap;
    private Uri filePath;
    private int PICK_IMAGE_REQUEST = 1;

    TextView txtSDK;
    Button btnSelectImage;
    TextView txtUriPath,txtRealPath;
    ImageView imgView;

    String realPath;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        txtSDK = (TextView) findViewById(R.id.txtSDK);
        btnSelectImage = (Button) findViewById(R.id.btnSelectImage);
        txtUriPath = (TextView) findViewById(R.id.txtUriPath);
        txtRealPath = (TextView) findViewById(R.id.txtRealPath);

        //Initializing the views
        editTextEmail = (EditText) findViewById(R.id.editTextEmail);
        editTextSubject = (EditText) findViewById(R.id.editTextSubject);
        editTextMessage = (EditText) findViewById(R.id.editTextMessage);

        imgView = (ImageView) findViewById(R.id.imgView);

        buttonSend = (Button) findViewById(R.id.buttonSend);
        btnImageChooser = (Button) findViewById(R.id.btnImageChooser);

        //Adding click listener
        buttonSend.setOnClickListener(this);
        btnImageChooser.setOnClickListener(this);
    }


    private void sendEmail() {
        //Getting content for email
        String email = editTextEmail.getText().toString().trim();
        String subject = editTextSubject.getText().toString().trim();
        String message = editTextMessage.getText().toString().trim();

        String realPath1 = txtRealPath.getText().toString();
        //Creating SendMail object
        SendMail sm = new SendMail(this, email, subject, message, realPath1);

        Toast.makeText(MainActivity.this, realPath1, Toast.LENGTH_LONG).show();
        //Executing sendmail to send email
        sm.execute();
    }


    private void showFileChooser() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
    }

    /*
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) {

            filePath = data.getData();
            try {
                bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
                imgView.setImageBitmap(bitmap);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
*/
    @Override
    public void onClick(View v) {
        if (v == buttonSend) {
            sendEmail();
        }
        if (v == btnImageChooser){
            //showFileChooser();

            // 1. on Upload click call ACTION_GET_CONTENT intent
            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
            // 2. pick image only
            intent.setType("image/*");
            // 3. start activity
            startActivityForResult(intent, 0);

            // define onActivityResult to do something with picked image
        }
    }




    @Override
    protected void onActivityResult(int reqCode, int resCode, Intent data) {
        if(resCode == Activity.RESULT_OK && data != null){

            // SDK < API11
            if (Build.VERSION.SDK_INT < 11)
                realPath = RealPathUtil.getRealPathFromURI_BelowAPI11(this, data.getData());

                // SDK >= 11 && SDK < 19
            else if (Build.VERSION.SDK_INT < 19)
                realPath = RealPathUtil.getRealPathFromURI_API11to18(this, data.getData());

                // SDK > 19 (Android 4.4)
            else
                realPath = RealPathUtil.getRealPathFromURI_API19(this, data.getData());


            setTextViews(Build.VERSION.SDK_INT, data.getData().getPath(),realPath);
        }
    }

    private void setTextViews(int sdk, String uriPath,String realPath){

        this.txtSDK.setText("Build.VERSION.SDK_INT: "+sdk);
        this.txtUriPath.setText("URI Path: "+uriPath);
        //this.txtRealPath.setText("Real Path: "+realPath);
        this.txtRealPath.setText(realPath);

        Uri uriFromPath = Uri.fromFile(new File(realPath));

        // you have two ways to display selected image

        // ( 1 ) imageView.setImageURI(uriFromPath);

        // ( 2 ) imageView.setImageBitmap(bitmap);
        Bitmap bitmap = null;
        try {
            bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uriFromPath));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        imgView.setImageBitmap(bitmap);

        Log.d("HMKCODE", "Build.VERSION.SDK_INT:"+sdk);
        Log.d("HMKCODE", "URI Path:"+uriPath);
        Log.d("HMKCODE", "Real Path: "+realPath);
    }

}

package com.example.rattapongt.androidsmtp;

/**
 * Created by Rattapongt on 2/16/2017.
 */

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;

import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;


//Class is extending AsyncTask because this class is going to perform a networking operation
public class SendMail extends AsyncTask<Void, Void, Void> {

    //Declaring Variables
    private Context context;
    private Session session;

    //Information to send email
    private String email;
    private String subject;
    private String message;
    private String realPath1;
    //Progressdialog to show while sending email
    private ProgressDialog progressDialog;

    //Class Constructor
    public SendMail(Context context, String email, String subject, String message, String realPath1) {
        //Initializing variables
        this.context = context;
        this.email = email;
        this.subject = subject;
        this.message = message;
        this.realPath1 = realPath1;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        //Showing progress dialog while sending email
        progressDialog = ProgressDialog.show(context, "Sending message", "Please wait...", false, false);
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        //Dismissing the progress dialog
        progressDialog.dismiss();
        //Showing a success message
        Toast.makeText(context, "Message Sent", Toast.LENGTH_LONG).show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        //Creating properties
        Properties props = new Properties();

        //Configuring properties for gmail
        //If you are not using gmail you may need to change the values
        props.put("mail.smtp.host", "XX.XXX.XX.X");
        props.put("mail.smtp.socketFactory.port", "110");
        //props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.port", "25");

        /*

                props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.socketFactory.port", "465");
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.port", "465");

         */

        //Creating a new session
        session = Session.getDefaultInstance(props,
                new javax.mail.Authenticator() {
                    //Authenticating the password
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(Config.EMAIL, Config.PASSWORD);
                    }
                });

        try {
            //Creating MimeMessage object
            MimeMessage mm = new MimeMessage(session);

            //////////
            // Create a multipar message
            Multipart multipart = new MimeMultipart();

            // Set text message part
            BodyPart messageBodyPart = new MimeBodyPart();

            multipart.addBodyPart(messageBodyPart);

            // Part two is attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "/storage/emulated/0/Pictures/Screenshots/Screenshot_20170202-091809.png";
            //String filename = realPath1;
            DataSource source = new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            multipart.addBodyPart(messageBodyPart);

            // Send the complete message parts
            //mm.setContent(multipart);


            /////////////


            //Setting sender address
            mm.setFrom(new InternetAddress(Config.EMAIL));
            //Adding receiver
            mm.addRecipient(Message.RecipientType.TO, new InternetAddress(email));
            //Adding subject
            mm.setSubject(subject);
            //Adding message
            //mm.setText(message);


            //mm.setContent(message, "text/html; charset=utf-8");
            mm.setContent(multipart);
            //Sending email
            Transport.send(mm);


        } catch (MessagingException e) {
            e.printStackTrace();
        }

        return null;
    }


}