Send text to specific contact programmatically (whatsapp)

I’ve found the right way to do this:

Source code: phone and message are both String.

    PackageManager packageManager = context.getPackageManager();
    Intent i = new Intent(Intent.ACTION_VIEW);

    try {
        String url = "https://api.whatsapp.com/send?phone="+ phone +"&text=" + URLEncoder.encode(message, "UTF-8");
        i.setPackage("com.whatsapp");
        i.setData(Uri.parse(url));
        if (i.resolveActivity(packageManager) != null) {
            context.startActivity(i);
        }
    } catch (Exception e){
        e.printStackTrace();
    }

Enjoy yourself!