How to get the summation of values using gpath sum() in restassured on JSON Object

I was trying to find the summation of deceased count from JSON object extract from the following JSON response

https://api.covid19india.org/state_district_wise.json

Snippet from above is json

"Maharashtra": {
    "districtData": {
      "Ahmednagar": {
        "notes": "",
        "active": 4206,
        "confirmed": 275516,
        "migratedother": 1,
        "deceased": 5565,
        "recovered": 265744,
        "delta": {
          "confirmed": 559,
          "deceased": 4,
          "recovered": 0
        }
      },

I want to find the sum of the deceased from the state of Maharashtra. I know we can use collect on JSONArray but here is JSONObject. I tried following but to no avail

int value=jsonPath.get("Maharashtra.districtData.collect{it.deceased}.sum()");

There are 2 deceased keys in the object, I assume that you only want the deceased in the outer object. The simplest solution I get so far.

@Test
void name3() {
    Response res = RestAssured.given()
            .get("https://api.covid19india.org/state_district_wise.json");
    Map<String, ?> data = res.jsonPath().getMap("Maharashtra.districtData");
    Set<String> keys = data.keySet();
    int sum = keys.stream()
            .mapToInt(key ->
               JsonPath.read(res.asString(), String.format("$.Maharashtra.districtData.[\"%s\"].deceased", key)))
            .sum();
    System.out.println(sum); //126851
}

In case, you don't want to use Java8 stream.

int sum = 0;
for (String key : keys) {
    int deceased = JsonPath.read(res.asString(), String.format("$.Maharashtra.districtData.[\"%s\"].deceased", key));
    sum += deceased;
}

I use JsonPath (com.jayway.jsonpath.JsonPath)

pom.xml

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.6.0</version>
</dependency>

Update

I come up with another solution, that using mapping POJO.

@Test
void name4() {
    Response res = RestAssured.given()
            .get("https://api.covid19india.org/state_district_wise.json");

    Configuration configuration = Configuration.builder()
            .jsonProvider(new JacksonJsonProvider())
            .mappingProvider(new JacksonMappingProvider())
            .build();

    List<DistrictData> data = JsonPath.using(configuration).parse(res.asString())
            .read("$.Maharashtra.districtData.*", new TypeRef<>() {});

    int sum = data.stream().mapToInt(DistrictData::getDeceased).sum();
    System.out.println(sum); //126851
}

POJO

import lombok.Data;
import java.util.Map;

@Data
public class DistrictData {
    private String notes;
    private int active;
    private int confirmed;
    private int migratedother;
    private int deceased;
    private int recovered;
    private Map<String, Object> delta;
}