How to send JSON data as response in nanohttpd

Question

I am using the nanohttpd server in my project. The GET Request should send a JSON file as response but nanohttpd only allows String. How can I do this?

This is the GET method:

class GetHandler{
JSONObject response;
JSONObject doGet(Queue queue){
    Map.Entry<String, Message> entry = (Map.Entry<String, Message>)queue.getQueue().entrySet().iterator().next();
    String key = entry.getKey();
    String value = entry.getValue().getText();
    int reCount = entry.getValue().increaseCount();
    queue.getQueue().remove(key);
    Date date = new Date();
    long time = date.getTime();
    queue.getInFlightQueue().put(key,new Message(value, reCount, time));
    System.out.println("ID : " + key + " Message Body : " + value);
    response.put("ID",key);
    response.put("Message Body", value);
    return response;
}
}

This is the Handling part:

if (uriComponents[1].equals("queue") && mainHashMap.containsKey(uriComponents[2])) {
    if (mainHashMap.get(uriComponents[2]).getQueue().isEmpty()) {
        response = "Error : trying to access an empty queue";
        return newFixedLengthResponse(NanoHTTPD.Response.Status.NOT_FOUND, "text/plain", response);
   } else {
        JSONObject message = implementGet.doGet(mainHashMap.get(uriComponents[2]));
        return newFixedLengthResponse(NanoHTTPD.Response.Status.OK, "text/plain", message.toJSONString());
        }
} else {
            response = "Error : Given queue name doesn't exits. Usage:- GET/queue/<queue_name>";
            return newFixedLengthResponse(NanoHTTPD.Response.Status.NOT_FOUND, "text/plain", response);
}

JSON is a textual format so you can stringify it to set it in the response of the GET (I suppose, or use a POST if you need to send the JSON with the request). — AxelH, May 08 '18 at 06:25
I've tried that but it doesn't work. When I convert it to a string, the GET request doesn't return anything. — Pooja, May 08 '18 at 06:40
Can you show us ? It is hard to help without seeing what you are doing for the moment. Use the [edit] to add a snippet of your code. See [ask], without more information I can't help and the question would end up closed as too broad. That's not your first question, you know how that works ;) — AxelH, May 08 '18 at 06:40
First thing, I see you use `text/plain`, try with `application/json` instead. (even if this is a `message.toJSONString()` used, The message will know that the content is a JSON. Then, what is the result of this solution ? Is the JSON correct ' (what is the result of `message.toJSONString()`). FYI: I don't know `nanoHTTP` so that part is left for others to check. — AxelH, May 08 '18 at 06:52

score 2 · Accepted Answer · answered May 08 '18 at 08:00

2

Instead of using a JSON object, I used a JSON String something like "{\"id\":\"abcd\", \"message\",\"1234\"}" and it worked.

answered May 08 '18 at 08:00

Pooja

97
12

1

Update: I used a JSON Builder eventually and converted that to a string – Pooja Jun 03 '18 at 04:42

How to send JSON data as response in nanohttpd

1 Answers1