SendTextToWA.java

private void openWhatsApp() {
        // Ganti nomermu
        String smsNumber = "6283854775376";     // awal +62 berubah cuma 62 aja
        try {
            Intent sendIntent = new Intent("android.intent.action.MAIN");
            sendIntent.setAction(Intent.ACTION_SEND);
            sendIntent.setType("text/plain");
            sendIntent.putExtra(Intent.EXTRA_TEXT, "Aku Orang Ganteng dan Intelek");
            sendIntent.putExtra("jid", smsNumber + "@s.whatsapp.net");
            sendIntent.setPackage("com.whatsapp");
            startActivity(sendIntent);
        } catch(Exception e) {
            Toast.makeText(this, "Error/n" + e.toString(), Toast.LENGTH_SHORT).show();
        }
    }