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Parsing JSON in Java and data manipulation

I'm super new to Java and am trying to parse JSON and manipulate the data into a final data structure as shown below.
I have this model:
public class StoreInfo {
private String storeName;
private String storeCode;
private List<StoreLocations> locations = new ArrayList<>();
}
Here is the JSON response I get from calling Redis:
redisResult = "[{
storeName: 'Walmart',
storeCode: '0001',
locations: [ [Object] ]
},
{
displayName: 'Wegmans',
storeCode: '0002',
locations: [ [Object] ]
}]"
When I call Redis, I use the keyName groceryStores and the fieldName 1.
I want to have a resulting data structure that looks like this:
groceryStores: { 1 : [
{
storeName: 'Walmart',
storeCode: '0001',
locations: [ [Object] ]
},
{
displayName: 'Wegmans',
storeCode: '0002',
locations: [ [Object] ]
}]
I'm having lots of trouble using Jackson to parse the initial JSON string into the type StoreInfo. When I try the following, I get an exception from Jackson:
StoreInfo[] storeInfoArray = objectMapper.readValue(redisResult, StoreInfo[].class);
I don't understand how I would create an array of StoreInfo objects.
Then, to use the key and field in order to create my final data structure.
I'm super new to Java and I have figured out how to do the latter part in Javascript, but how to do it in Java?
// Assuming the JSON response has been parsed
function addResponse (response, key, field, data) {
response[key] = {}
response[key][field] = data
return response
}

Easiest Option is create a wrapper class for StoreInfo i.e.
class StoreInfoDTO {
List<StoreInfo> storeInfoList;
//getter and setters
}
Now use ObjectMapper as:
StoreInfo[] storeInfoArray = objectMapper.readValue(redisResult,
StoreInfoDTO.class).getStoreInfoList();
Part2, setting the Value in response :
class ResponseDTO {
#JsonProperty("groceryStores")
Map<Integer, List<StoreInfo>> props;
//getter and setters
}
Now to use it :
ResponseDTO responseDTO = new ResponseDTO();
GrosseryStores grosseryStores = new GrosseryStores();
ArrayList<StoreInfo> storeInfos = new ArrayList<StoreInfo>();
storeInfos.add(new StoreInfo("SN1","1234"));
ArrayList<StoreInfo> storeInfos1 = new ArrayList<StoreInfo>();
storeInfos1.add(new StoreInfo("SN2","1236"));
Map<Integer, List<StoreInfo>> map = new HashMap<>();
map.put(1,storeInfos);
map.put(2,storeInfos1);
responseDTO.setProps(map);

How to satisfy nested generic requirement of Class<T> in kotlin

I am trying to call a method where it's signature includes a parameter of Class<T>
below is the sample code in kotlin
val response: ResponseEntity<ResponseObject<*>> = testRestTemplate.postForEntity("/users", user, ResponseObject::class.java)
what i am trying to achieve is to get rid of the <*> in responseObject and let it be
val response: ResponseEntity<ResponseObject<User>> = ???
but i am not sure on what is the correct syntax to provide to satisfy the Class<T> requirement
i tried
ResponseObject<User::class.java>::class.java
but that is not a valid syntax. any pointers?
The real problem is if i use * i don't know how exactly to infer the User instance from there correctly.

ok I managed to solve my problem using type casting using when
#Test
fun testCreateUser() {
val user = User(id = null)
val response = testRestTemplate.postForEntity("/users", user, ResponseObject::class.java)
val responseObject = response.body
when (val returnedUser = responseObject.model) {
is User -> {
assertNotNull(returnedUser.id)
assertEquals(UserStatus.active, returnedUser.status)
}
}
}

If you can change the signature of the method then you may try something similar to the following:
class ResponseEntity<T : Any>(val body: T)
class ResponseObject<T : Any>(val model: T)
data class User(val id: Long, val status: String)
fun <M : Any, K : ResponseObject<M>> postForEntity(paht: String, model: M): ResponseEntity<K> {
return TODO()
}
val response: ResponseEntity<ResponseObject<User>> = postForEntity("/users", User(1, "good"))

You could use
#Suppress("UNCHECKED_CAST")
val response = testRestTemplate.postForEntity("/users", user, ResponseObject::class.java as Class<ResponseObject<User>>)
Or a helper function if you need it more than once for different parameters
inline fun <reified T> classOf<T>() = T::class.java
val response = testRestTemplate.postForEntity("/users", user, classOf<ResponseObject<User>>())
(in both cases the type ResponseEntity<ResponseObject<User>> should be inferred)

How to convert a BigInteger to Objectid with spring data

I working with java 8 and the following spring specification:
<spring.version>4.2.3.RELEASE</spring.version>
<spring.security.version>4.0.3.RELEASE</spring.security.version>
<spring.data.version>1.8.1.RELEASE</spring.data.version>
I have a document that obviously has an _id, which is working perfectly, but I have another field that stores a reference that is another _id, this is my expected JSON
{
"_id" : ObjectId("56c8f330d4c65e543ceac8de"),
"companyId" : ObjectId("56c8f330d4c65e543ce8c8de"),
"name" : "COMPANY S.R.L",
more fields......
}
I have created the following converter:
#Component
public class PurchaseWriterConverter implements Converter<Purchase, DBObject>
{
#Override public DBObject convert(Purchase source)
{
DBObject dbo = new BasicDBObject();
dbo.put("_id", source.getId());
**ObjectId objCompany = new ObjectId(source.getCompany().toString(16));
dbo.put("company", objCompany);**
dbo.put("supplier", source.getSupplier());
dbo.put("status", source.getStatus().toString());
dbo.put("attendant", source.getAttendant());
dbo.put("cashier", source.getCashier());
List<Object> orders = new BasicDBList();
for (OrderWrapper order : source.getOrders())
{
DBObject orderDBObject = new BasicDBObject();
orderDBObject.put("description", order.getDescription());
orderDBObject.put("basePrice", order.getBasePrice());
orderDBObject.put("grossWeight", order.getGrossWeight());
orderDBObject.put("netWeight", order.getNetWeight());
orderDBObject.put("subtotal", order.getSubtotal());
orderDBObject.put("totalWeight", order.getTotalWeight());
orders.add(orderDBObject);
}
dbo.put("orders", orders);
dbo.put("createDate", source.getCreateDate());
dbo.put("updateDate", source.getUpdateDate());
dbo.put("approvedBy", source.getApprovedBy());
dbo.put("createDate", source.getCreateDate());
dbo.put("updateDate", source.getUpdateDate());
dbo.removeField("_class");
return dbo;
}
}
The following lines are not working
dbo.put("_id", source.getId());
**ObjectId objCompany = new ObjectId(source.getCompany().toString(16));
So, I tried to create another converter in order to convert BigInteger to ObjectId, something like this
public class BigIntegerToObjectIdConverter implements Converter {
#Override
public ObjectId convert(BigInteger source) {
return source == null ? null : new ObjectId(source.toString());
}
}
But I getting the same error:
org.springframework.core.convert.ConversionFailedException: Failed to convert from type com.xxxxxxxxxxx.entity.Purchase to type com.mongodb.DBObject for value 'Purchase{company=1, orders=[com.xxxxxxx.equilibrium.wrapper.OrderWrapper#9cd3f65], supplier=26857458392532697059830357595, approvedBy='', status=TO_BE_APPROVED, attendant='User Admin', cashier=''}'; nested exception is java.lang.IllegalArgumentException: invalid ObjectId [1]
the value that I sending as a biginteger is "1".
Can anybody gives me some directions about how to convert a BigInteger to ObjectId or suggest something different.

I just answered to a similar question here https://stackoverflow.com/a/46508892/4660481
A valid ObjectId can be constructed from exactly 24 hexadecimal characters. In this case, your .toString(16) will return "1" which does not have a length of 24. What you would want in this case is "000000000000000000000001". You can resolve this issue by padding with 0s:
String hexString24 = StringUtils.leftPad(source.getCompany().toString(16), 24, "0");
ObjectId objCompany = new ObjectId(hexString24);

I am using JsonReader in Android, and i need a value inside the current object before parsing an inner object

My JSON object looks something like this:
{
id: 1
object:
{
object_id:1
key_for_1: "value for object type 1"
}
type: "object_type_1"
}
{
id: 2
object:
{
object_id:5
key_for_23: "value for object type 23"
}
type: "object_type_23"
}
So, basically i need "type" before i can parse object. Is there a way to ensure that I can grab the value for "type" before i grab "object"?
JsonReader is has pretty much the same methods as GSON. Here is how I am parsing it:
public CustomObject(JsonReader reader) throws IOException {
reader.beginObject();
while (reader.hasNext()) {
String name = reader.nextName();
if (name.equals("id")) {
clId = reader.nextDouble();
}
else if (name.equals("object")) {
innerObject = new InnerObject(reader);
}
else if (name.equals("type")) {
type = reader.nextString();
}
}
reader.endObject();
}
I don't want to just use a string builder because the actual JSON object I get back is HUGE (the one above is just a sample). I tried StringBuilder first and I am seeing quite a few out of memory problems which is why I wanted to move to JsonReader.
Any help would be awesome. Thanks

First of all to simplify parsing JSON object, you can use org.json library. Secondly, I think this is an invalid JSON object structure.
Do you intend to have an array of JSON objects with each item (Data in this case) having following name:value pairs?
{
"Data":
[
id: 1
object:
{
object_id:5
key_for_23: "value for object type 23"
}
type: "object_type_23"
},{ }]
{
}

Parsing JSON with java : dynamic keys

I need to create a JSON response with some dynamic fields in java. Here is an example of the JSON response I want to return :
{
"success": true,
"completed_at": 1400515821,
"<uuid>": {
type: "my_type",
...
},
"<uuid>": {
type: "my_type",
...
}
}
The "success" and the "completed_at" fields are easy to format. How can I format the fields? What would be the corresponding java object?
Basically I want to work with 2 java objects :
public class ApiResponseDTO {
private boolean success;
private DateTime completedAt;
...
}
and
public class AuthenticateResponseDTO extends ApiResponseDTO {
public List<ApplianceResponseDTO> uuids = new ArrayList<ApplianceResponseDTO>();
}
These java objects don't correspond to the expected JSON format. It would work if I could change the JSON format to have a list, but I can't change it.
Thanks a lot!

You can massage your data into JSON form using the javax.json library, specifically the JsonObjectBuilder and the JsonArrayBuilder. You'll probably want to nest a few levels of a toJson() method which will either give you the string representation you're looking for, or the JsonObject/JsonArray you desire. Something like this:
JsonArray value = null;
JsonArrayBuilder builder = Json.createArrayBuilder();
for (ApplianceResponseDTO apr : uuids) {
builder.add(apr.toJson());
}
value = builder.build();
return value;