twilio API issues when submitting whastapp query

Question

I'm using HttpURLConnection to post to https://api.twilio.com/2010-04-01/Accounts/****/Messages.json

this works for SMS - but when the txtTo and txtFrom are changed to To=whatsapp:+12345567&From=whatsapp:+123456778&Body=sacsacsac

it stops working ..... any ideas?

String message  = "To=" + txtTo + "&From=" + txtFrom + "&Body=" + txtBody;

byte[] postData = message.getBytes( StandardCharsets.UTF_8 );

Answer 1

String message = "From=" + URLEncoder.encode("whatsapp:" + txtFrom, "UTF-8") +"&Body=" + URLEncoder.encode(txtBody, "UTF-8") + "&To=" + URLEncoder.encode("whatsapp:" + txtTo, "UTF-8");