How to convert list data into json in java

Using gson it is much simpler. Use following code snippet:

 // create a new Gson instance Gson gson = new Gson(); // convert your list to json String jsonCartList = gson.toJson(cartList); // print your generated json System.out.println("jsonCartList: " + jsonCartList);

Converting back from JSON string to your Java object

 // Converts JSON string into a List of Product object Type type = new TypeToken<List<Product>>(){}.getType(); List<Product> prodList = gson.fromJson(jsonCartList, type); // print your List<Product> System.out.println("prodList: " + prodList);

public static List<Product> getCartList() {    JSONObject responseDetailsJson = new JSONObject();    JSONArray jsonArray = new JSONArray();    List<Product> cartList = new Vector<Product>(cartMap.keySet().size());    for(Product p : cartMap.keySet()) {        cartList.add(p);        JSONObject formDetailsJson = new JSONObject();        formDetailsJson.put("id", "1");        formDetailsJson.put("name", "name1");       jsonArray.add(formDetailsJson);    }    responseDetailsJson.put("forms", jsonArray);//Here you can see the data in json format    return cartList;}

you can get the data in the following form

{    "forms": [        { "id": "1", "name": "name1" },        { "id": "2", "name": "name2" }     ]}

Try these simple steps:

ObjectMapper mapper = new ObjectMapper();String newJsonData = mapper.writeValueAsString(cartList);return newJsonData;ObjectMapper() is com.fasterxml.jackson.databind.ObjectMapper.ObjectMapper();