0

I would like to parse Java String containing json into some Java container/collection.

I have no problem with string A which contain something like below:

{"id":"0bda5158-a533-498a-8657-79aec0c3fb65","name":"Andrzej","email":"test@gmail.com"}

Simple json ==> string <-> string. The problem is when the string B contains something like below (array of json):

[{"id":"0bda5158-a533-498a-8657-79aec0c3fb65","name":"Andrzej","email":"test@gmail.com"}]

This is the code which I used to parse:

private static class TestResponse {

    public final String body;
    public final int status;

    public TestResponse(int status, String body) {
        this.status = status;
        this.body = body;
    }

    public Map<String, String> json() {
        return new Gson().fromJson(body, HashMap.class);
    }
}

Request method looks like:

private TestResponse request(String method, String path) {
        try {
            URL url = new URL("http://localhost:4567" + path);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod(method);
            connection.setDoOutput(true);
            connection.connect();
            String body = IOUtils.toString(connection.getInputStream());
            return new TestResponse(connection.getResponseCode(), body);
        } catch (IOException e) {
            e.printStackTrace();
            fail("Sending request failed: " + e.getMessage());
            return null;
        }
    }

Everything work for the first string A. I have been doing something like below (simple Map):

TestResponse res = request("PUT", "/user/create?name=Andrzej&email=test@gmail.com");
Map<String, String> json = res.json();

The problem is with the string B - there is an array of json. There I cannot use simple Map. I do not know how to solve it. Please help me and thank you in advance.

Dekoderer Dekoderer
  • 161
  • 1
  • 11
  • The answer is following. In order to parse `List` you need to do `new Gson().fromJson(body, ArrayList.class);` instead of `HashMap.class`. You need to implement some strategy parser. – Dmytro Chasovskyi Dec 30 '18 at 14:00
  • `List> mapList = new ObjectMapper().readValue(json, new TypeReference>>(){});` – Nikhil Dec 30 '18 at 14:02

0 Answers0