You have json array so you need to read like below
try {
JSONArray jsonArray=new JSONArray("your data");
if(jsonArray.length()>0){
for(int i=0;i<jsonArray.length();i++){
JSONObject jsonObject=jsonArray.getJSONObject(i);
JSONObject messageObj=jsonObject.getJSONObject("message");
String user_id=messageObj.getString("user_id");
String user_type=messageObj.getString("user_type");
----and so on.
}
}
} catch (Exception e) {
e.printStackTrace();
}