I can't find toByteArray() as @atrioom said, so I use StringWriter, please try:

public void writeListToJsonArray() throws IOException {  

    //your list
    final List<Event> list = new ArrayList<Event>(2);
    list.add(new Event("a1","a2"));
    list.add(new Event("b1","b2"));


    final StringWriter sw =new StringWriter();
    final ObjectMapper mapper = new ObjectMapper();
    mapper.writeValue(sw, list);
    System.out.println(sw.toString());//use toString() to convert to JSON

    sw.close(); 
}

Or just use ObjectMapper#writeValueAsString:

    final ObjectMapper mapper = new ObjectMapper();
    System.out.println(mapper.writeValueAsString(list));

From Eugene Tskhovrebov

List<MyClass> myObjects = Arrays.asList(mapper.readValue(json, MyClass[].class))

This solution seems to be the best for me.

public JSONObject findOccurrByFileUUID(UUID filePefin) throws JSONException {

    StringBuilder strQuery = new StringBuilder();
    strQuery.append("SELECT c.\"name\" AS creditorname, d.\"name\" AS debtorname, concat(b2.\"type\",'-',b2.\"number\",'-',b2.parcel) AS docto, b2.uniquenumber, to_char(b.dateoccurr,'DD/MM/YYYY HH24:MI:SS') AS dateoccur, to_char(b.createddate, 'DD/MM/YYYY HH24:MI:SS') AS createddate, b.statusnegatived, l.username FROM billnegativedoccurr b \n" +
                    "LEFT JOIN billnegatived b2 ON b2.uuid = b.billnegativeduuid \n" +
                    "LEFT JOIN creditor c ON c.tenantowner_uuid = b2.tenant_uuid AND c.uuid = b2.creditor_uuid \n" +
                    "LEFT JOIN debtor d ON d.tenantowner_uuid = b2.tenant_uuid AND d.uuid = b2.debtor_uuid \n" +
                    "INNER JOIN login l ON l.uuid = b.useroccurr \n" +
                    "WHERE b.filepefinuuid = :filePefin");

    Query query = eM.createNativeQuery(strQuery.toString()); //no entity mapping
    query.setParameter("filePefin", filePefin);
    List<Object[]> queryList = query.getResultList();
    JSONArray array = new JSONArray();
    JSONObject obj = new JSONObject();

    for (Object[] result : queryList) {

        JSONObject object = new JSONObject();
        object.put("creditorName", result[0]);
        object.put("debtorName", result[1]);
        object.put("docto", result[2]);
        object.put("uniquenumber", result[3]);
        object.put("dateoccur", result[4]);
        object.put("createddate", result[5]);
        object.put("statusnegatived", result[6]);
        object.put("username", result[7]);

        array.put(object);
    }

    return obj.put("Values", array);
}

Change the return result from Map to List<CscGodownBean> and put : retrun godown_list So;

@RequestMapping("/getGodowns")
public @ResponseBody List<CscGodownBean>
getGodownsBasedOnDistrict(@RequestParam(value="district_code") String 
dist_code) {

List<CscGodownBean> godown_list = new ArrayList<CscGodownBean>();
String exception = null;
try
{
    //getting name and codes here
    godown_list = scm_service.getGodownListBesedOnDistCode(dist_code);
}catch(Exception ex)
{
   ex.printStackTrace();
   exception = ex.getMessage();
}

return godown_list ;
}

UPDATE

And you can return result as string and you will get what you need :

@RequestMapping("/getGodowns")
public @ResponseBody String
getGodownsBasedOnDistrict(@RequestParam(value="district_code") String 
dist_code) {

List<CscGodownBean> godown_list = new ArrayList<CscGodownBean>();
String exception = null;
try
{
    //getting name and codes here
    godown_list = scm_service.getGodownListBesedOnDistCode(dist_code);
}catch(Exception ex)
{
   ex.printStackTrace();
   exception = ex.getMessage();
}
ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
    String arrayToJson = objectMapper.writeValueAsString(godown_list);
    System.out.println("Convert List to JSON :");
    System.out.println(arrayToJson);

return arrayToJson ;
}

The returned String is json format.

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" } 
    ]
}