Intent sendIntent = new Intent(Intent.ACTION_VIEW);
    StringBuilder uri = new StringBuilder("sms:");
    for (int i = 0; i < contacts.size(); i++) {
        uri.append(contacts.get(i).getNumber());
        uri.append(", ");
    }
    sendIntent.putExtra("sms_body", "");
    sendIntent.setType("vnd.android-dir/mms-sms");
    sendIntent.setData(Uri.parse(uri.toString()));
    startActivity(sendIntent);

Intent smsIntent = new Intent(Intent.ACTION_SENDTO,Uri.parse("smsto:5551212;5551212"));
smsIntent.putExtra("sms_body", "sms message goes here");
startActivity(smsIntent);

StringBuilder uri = new StringBuilder("sms:");
    for (int i = 0; i < yourarray.length; i++) {
        uri.append(yourarray[i]);
        uri.append(", ");
    }
    Intent smsIntent = new Intent(Intent.ACTION_VIEW);
    smsIntent.setType("vnd.android-dir/mms-sms");
    smsIntent.setData(Uri.parse(uri.toString()));
    smsIntent.putExtra("sms_body", "Body of Message");
    startActivity(smsIntent);