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how do I access object "player" inside the array retrofit 2 / android studio

I would like to unmarshal a list of players from this nested json using retrofit 2 and Gson in android:
{
"api": {
"status": 200,
"message": "GET players/playerId/44",
"results": 1,
"filters": [
...
],
"players": [
{
"firstName": "Kent",
"lastName": "Bazemore",
"teamId": "29",
"yearsPro": "7",
"collegeName": "Old Dominion",
"leagues": {
"standard": {
"jersey": "24",
"active": "1",
"pos": "G-F"
}
}
}
]
}
}
Can anyone help?

If you are using Retrofit, I would advise you to look into Gson/Jackson/Moshi converters. These help in converting your JSON responses to plain Java objects.
You should then be able to access it as
api.getPlayers() -> array of players

You first need to create a model class then you can access the particular key. For example:
public class ResponseItem {
private int status;
private String message;
private List<String> players;
public int getStatus() {
return status;
}
public void setStatus(int status) {
this.status = status;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public List<String> getPlayers() {
return players;
}
public void setPlayers(List<String> players) {
this.players = players;
}
Add the following code snippet in your retrofit method:
if (response.isSuccessful()) {
ResponseItem responseItem;
responseItem = response.body();
}
P.S. Make sure to complete the model class using the same pattern.

How to avoid too many classes in jackson Java?

I have JSON serialization and deserialization is done using Jackson in java.
I have so many JSON fields that to serialize and deserialize I have multiple single-member classes, is there any better way to do this?
I don't have any limitations on using Jackson library, that is the library I have used for most of my cases.
public class Data{
public String type;
public int id;
public Attributes attributes;
public Relationships relationships;
}
public class Category{
public Data data;
}
public class Service{
public Data data;
}
public class Priority{
public Data data;
}
public class Status{
public Data data;
}
public class User{
public Data data;
}
public class Relationships{
public Category category;
public Service service;
public Priority priority;
public Status status;
public User user;
}
public class Root{
public Data data;
}
My sample JSON for which I am serializing looks like below.
{
"data": {
"id": 111,
"type": "op type",
"attributes": {
"title": "Some title"
},
"relationships": {
"category": {
"data": {
"type": "category",
"id": 1
}
},
"service": {
"data": {
"type": "service",
"id": 3
}
},
"priority": {
"data": {
"type": "priority",
"id": 1
}
},
"status": {
"data": {
"type": "status",
"id": 3
}
},
"user": {
"data": {
"type": "user",
"id": 3
}
}
}
}
}

Because Category, Service and others have the same fields data, if you create class manually, you can just create one common class DataWrapper. But I also see you said you use jsonschema2pojo rather than create class manually.
public class Data{
public String type;
public int id;
public Attributes attributes;
public Relationships relationships;
}
public class DataWrapper {
public Data data;
}
public class Relationships{
public DataWrapper category;
public DataWrapper service;
public DataWrapper priority;
public DataWrapper status;
public DataWrapper user;
}
public class Root{
public Data data;
}

Deserialize with Dependency Injection

I have a nested Json object and I want to deserialize it into the Account object.
Json example:
{
"status": "OK",
"output": {
"accountNum": ".....",
"customerType": ".....",
"homeNumber": ".....",
"homeIndicator": ".....",
"eligible": true,
"startDate": "2017-01-01",
"contactDetails": {
"firstName": ".....",
"lastName": ".....",
"addressStreet": ".....",
},
"indicators": [
"ind1",
"ind2",
],
"employees": [
{
"name": ".....",
"email": ".....",
"model": ".....",
"program": [
{
"name": ".....",
"date": "....."
},
{
"name": ".....",
"date": "....."
}
],
"type": ".....",
"indicators": [
"....."
],
"customer": false
}
],
}
}
Since it’s a nested Json I am using the following method to do that:
ObjectMapper mapper = new ObjectMapper();
Flux<Timed<XXXDto >> mergedMonos = Flux.fromIterable(jsonList).flatMapSequential(Function.identity());
mergedMonos.map(timed -> mapper.valueToTree(timed.get())).collectList().subscribe(System.out::print);
#Component
public class XXXDto {
#Autowired
private Account account;
#JsonProperty("output")
private void unpackOutput(Map<String, Object> output) {
//Account a1 = new Account();
// this.account.setAccountNum is null
output.get("accountNum");
The problem is that I want to store the "accountNum" in the Account object but during the deserialization the inject Account is null.
I can create an instance in unpackOutput method but I would to see if there is another option via injection.
Any advice will be appreciated.
Thank you

I was able to deserialise the example input using these classes and this code.
First of all, here is the formatted input:
{
"status":"OK",
"output":{
"accountNum":".....",
"customerType":".....",
"homeNumber":".....",
"homeIndicator":".....",
"eligible":true,
"startDate":"2017-01-01",
"contactDetails":{
"firstName":".....",
"lastName":".....",
"addressStreet":"....."
},
"indicators":[
"ind1",
"ind2"
],
"employees":[
{
"name":".....",
"email":".....",
"model":".....",
"program":[
{
"name":".....",
"date":"....."
},
{
"name":".....",
"date":"....."
}
],
"type":".....",
"indicators":[
"....."
],
"customer":false
}
]
}
}
These are the classes I used:
public class ContactDetails{
public String firstName;
public String lastName;
public String addressStreet;
}
public class Program{
public String name;
public String date;
}
public class Employee{
public String name;
public String email;
public String model;
public List<Program> program;
public String type;
public List<String> indicators;
public boolean customer;
}
public class Output{
public String accountNum;
public String customerType;
public String homeNumber;
public String homeIndicator;
public boolean eligible;
public String startDate;
public ContactDetails contactDetails;
public List<String> indicators;
public List<Employee> employees;
}
public class Root{
public String status;
public Output output;
}
And this is the code I used to deserialise:
ObjectMapper objectMapper = new ObjectMapper();
Root root = objectMapper.readValue(input2, Root.class);
It was pretty simple so Im wondering if I missed something.

Serialize Java Object attribute to JSON

I have an API built in Java Spring that return (using JacksonJaxbJsonProvider 2.5.5) a JSON object from this class:
public class FieldValues {
private String code;
private Object value;
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public Object getValue() {
return value;
}
public void setValue(Object value) {
this.value = value;
}
}
In the main object I've
#JsonRootName(value = "WorkRequest")
#XmlRootElement(name = "WorkRequest")
#JsonIgnoreProperties(ignoreUnknown = true)
public class WorkRequestDTOResponse {
private List<FieldValues> fieldValues;
public List<FieldValues> getFieldValues() {
return fieldValues;
}
public void setFieldValues(List<FieldValues> fieldValues) {
this.fieldValues = fieldValues;
}
}
But the output of the fieldValues object is this:
"fieldValues": [
{
"code": "anomaly",
"value": {
"#xsi.type": "ns3:boolean",
"$": "true"
}
},{
"code": "internal_note",
"value": {
"#xsi.type": "ns3:string",
"$": "Test text example"
}
}
]
instead what I need is this:
"fieldValues": [
{
"code": "anomaly",
"value": true
},{
"code": "internal_note",
"value": "Test text example"
}
]
This is my JSON Provider:
public class ErmesJSONProvider extends JacksonJaxbJsonProvider {
public ErmesJSONProvider() {
ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true);
mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
mapper.configure(SerializationFeature.WRAP_ROOT_VALUE, true);
mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, true);
mapper.configure(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED, false);
_mapperConfig.setMapper(mapper);
_mapperConfig.getConfiguredMapper().setAnnotationIntrospector(new JacksonAnnotationIntrospector());
}
}
Trying to use a String instead an object:
public class FieldValues {
private String code;
private String value;
But if I set this value as String fieldValues.setValue("true"), the JSON output is "value": true instead "value": "true"
Likewise if I set this value as String but with an Integer fieldValues.setValue("1"), the JSON output is "value": 1 instead "value": "1"
If I print the return object using ObjectMapper I've the right JSON:
String payload = new ObjectMapper().writeValueAsString(requestResult)
but if I return a Response like this:
return Response.status(Response.Status.CREATED).entity(new GenericEntity<RequestResult>(requestResult){}).build()
it return the wrong JSON.
I can't understand why 😥
Someone can help me? Thanks.

Unable to deserialize a JSON response from SonarQube using the gson library

I'm trying to use gson to deserialize some data that I'm getting back from a SonarQube API on various code metrics. This is an example of the raw JSON coming back from the server:
{
"component": {
"id": "c5fc9d6k-e28b-4ea0-8922-df18c7e07ac1",
"key": "APP:master",
"name": "master",
"qualifier": "TRK",
"measures": [
{
"metric": "coverage",
"value": "19.9",
"periods": [
{
"index": 1,
"value": "0.09999999999999787"
},
{
"index": 2,
"value": "0.09999999999999787"
},
{
"index": 3,
"value": "0.6999999999999993"
},
{
"index": 4,
"value": "8.7"
}
]
},
{
"metric": "overall_coverage",
"value": "55.7",
"periods": [
{
"index": 1,
"value": "0.0"
},
{
"index": 2,
"value": "0.0"
},
{
"index": 3,
"value": "3.0"
},
{
"index": 4,
"value": "55.7"
}
]
},
{
"metric": "ncloc",
"value": "1089127",
"periods": [
{
"index": 1,
"value": "3835"
},
{
"index": 2,
"value": "3835"
},
{
"index": 3,
"value": "-74350"
},
{
"index": 4,
"value": "102501"
}
]
}
]
}
}
I'm attempting to deserialize it into a Component class with this code:
public Component getComponentMeasures(String componentKey, List<String> measures) throws ClientProtocolException,
IOException, JsonSyntaxException, UnsupportedOperationException, JSONException
{
HttpGet request = new HttpGet(baseURL + String.format("/api/measures/component?componentKey=%s&metricKeys=%s",
componentKey, StringUtils.join(measures, ",")));
HttpResponse response = client.execute(request);
Gson gson = new Gson();
String componenta = getJSONResponse(response);
System.out.print(componenta);
Component component = gson.fromJson(componenta, Component.class);
return component;
}
This is the Component class that I'm deserializing it into:
public class Component {
#SerializedName("id")
#Expose
private String id;
#SerializedName("key")
#Expose
private String key;
#SerializedName("name")
#Expose
private String name;
#SerializedName("qualifier")
#Expose
private String qualifier;
#SerializedName("path")
#Expose
private String path;
#SerializedName("measures")
#Expose
private Measure[] measures = null;
public String getId() {
return id;
}
public String getKey() {
return key;
}
public String getName() {
return name;
}
public String getQualifier() {
return qualifier;
}
public String getPath() {
return path;
}
public Measure[] getMeasures() {
return measures;
}
}
This Component class also contains an array of Measures which in turn contain an array of periods.
Measure Class:
public class Measure {
#SerializedName("metric")
#Expose
private String metric;
#SerializedName("value")
#Expose
private String value;
#SerializedName("periods")
#Expose
private Period[] periods = null;
public String getMetric() {
return metric;
}
public String getValue() {
return value;
}
public Period[] getPeriods() {
return periods;
}
}
Period class:
public class Period {
#SerializedName("index")
#Expose
private Integer index;
#SerializedName("value")
#Expose
private String value;
public Integer getIndex() {
return index;
}
public String getValue() {
return value;
}
}
When I run this code, the deserialized component is null. Any ideas on anything that I may be doing wrong here? Note that there is an extra parameter in the Component class, "path", that is null in the JSON. This is optional and exists in other classes which contain a collection of Component objects. In those cases, this Component object and JSON deserialize fine. I've compared the JSON side-by-side and they are identical. I only seem to have the issue when trying to deserialize a standalone component object. Any help would be greatly appreciated!

Note that your JSON document is a JSON object with a single property (the path: $.component) with a nested component, however you're trying to deserialize it as if it were the top-most object:
Component component = gson.fromJson(componenta, Component.class);
Just create another class to match the top-most single property object, say something like:
final class Response {
#SerializedName("component")
#Expose
final Component component = null;
}
And then sample code like
final Response response = gson.fromJson(componenta, Response.class);
for ( final Measure measure : response.component.measures ) {
System.out.println(measure.metric + " " + measure.value);
}
will print the following output:
coverage 19.9
overall_coverage 55.7
ncloc 1089127

Sonar has an SDK for their API that encapsulates all of this and you don't have to create your own classes, etc. I used it to get info out like you're doing. See https://docs.sonarqube.org/display/SONARQUBE45/Using+the+Web+Service+Java+client and my use of it: http://myvogonpoetry.com/wp/2013/02/21/using-the-sonar-rest-api-for-weekly-emails/