Getting an error in one signal push notification : contents must be key/value collections by language code

Question

I'm trying to set as a simple message to the contents field in onesignal request body. And I'm getting an error message "contents must be key/value collections by language code".

ObjectNode jsonMessage = Json.newObject();
jsonMessage.put("contents", "{\"en\": \"English Message\"");

Push Response******** {"errors":["contents must be key/value collections by language code"]}

Answer 1

Make sure you format the JSON string correctly, e.g:

{"en": "English Message", "es": "Spanish Message"}

Reference