convert list to json using Jackson - json

Question

With the below code I have converted list to json but the format is as
follows:
{"GodownMaster":[{"pname":"FCI CHARLAPALLI","pcode":"16042"},
{"pname":"MLS CIRCLE 1 L.B. NAGAR","pcode":"16016"},{"pname":"MLS CIRCLE 4
AZAMABAD","pcode":"16003"},{"pname":"MLS CIRCLE 6
VIDYANAGAR","pcode":"16005"},{"pname":"OTHERS","pcode":"1699"}]}
but I want to convert it as :
[{"pname":"FCI CHARLAPALLI","pcode":"16042"},
{"pname":"MLS CIRCLE 1 L.B. NAGAR","pcode":"16016"},{"pname":"MLS CIRCLE 4
AZAMABAD","pcode":"16003"},{"pname":"MLS CIRCLE 6
VIDYANAGAR","pcode":"16005"},{"pname":"OTHERS","pcode":"1699"}]
Below is my spring controller :
#RequestMapping("/getGodowns")
public #ResponseBody Map
getGodownsBasedOnDistrict(#RequestParam(value="district_code") String
dist_code) {
List<CscGodownBean> godown_list = null;
Map<String, List<CscGodownBean>> m = new HashMap();
String exception = null;
try
{
//getting name and codes here
godown_list = scm_service.getGodownListBesedOnDistCode(dist_code);
}catch(Exception ex)
{
ex.printStackTrace();
exception = ex.getMessage();
}
if(godown_list!=null) {
for(int i=0;i<godown_list.size();i++) {
m.put("GodownMaster",godown_list);
}
}
return m;
}

Answer 1

Why are you putting your list into Map? Code looks weird. If you want to return a list, just do it:
#RequestMapping("/getGodowns")
public #ResponseBody List<CscGodownBean> getGodownsBasedOnDistrict(#RequestParam(value="district_code") String dist_code) {
List<CscGodownBean> godown_list = null;
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;
}

Answer 2

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.

Answer 3

Here is what I have used:
#RequestMapping("/alluserreportJSON")
public #ResponseBody String getusersJSON() {
ObjectMapper objectMapper = new ObjectMapper();
//Set pretty printing of json
objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
List<AppUser> userlist = null;
#SuppressWarnings("unused")
String exception = null;
String arrayToJson = null;
try {
userlist = userService.findAllUsers();
arrayToJson = objectMapper.writeValueAsString(userlist);
} catch (Exception ex) {
ex.printStackTrace();
exception = ex.getMessage();
}
return arrayToJson;
}
Hope it helps someone. You can see it working here.

Answer 4

You add return type as Map, still you want the same then Just in ajaxComplete() put code;
var response = '{"GodownMaster":[{"pname":"FCI CHARLAPALLI","pcode":"16042"}, {"pname":"MLS CIRCLE 1 L.B. NAGAR","pcode":"16016"},{"pname":"MLS CIRCLE 4 AZAMABAD","pcode":"16003"},{"pname":"MLS CIRCLE 6 VIDYANAGAR","pcode":"16005"},{"pname":"OTHERS","pcode":"1699"}]}'
JSON.stringify(JSON.parse(response).GodownMaster);