I am trying to parse the JSON result from the Wordpress plugins API using Retrofit2 and GSON. I have generated my POJO using the well known website and modified it into the following model:
PluginsApiResponse.java
public class PluginsApiResponse {
#SerializedName("plugins")
#Expose
private List<Plugin> plugins = null;
public List<Plugin> getPlugins() {
return plugins;
}
public void setPlugins(List<Plugin> plugins) {
this.plugins = plugins;
}
}
Plugin.java
public class Plugin {
#SerializedName("name")
#Expose
private String name;
#SerializedName("homepage")
#Expose
private String homepage;
#SerializedName("screenshots")
#Expose
private Screenshots screenshots;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getHomepage() {
return homepage;
}
public void setHomepage(String homepage) {
this.homepage = homepage;
}
public Screenshots getScreenshots() {
return screenshots;
}
public void setScreenshots(Screenshots screenshots) {
this.screenshots = screenshots;
}
}
Screenshots.java
public class Screenshots {
#SerializedName("1")
#Expose
private com.dkalsan.retrofitwordpress._1 _1;
#SerializedName("2")
#Expose
private com.dkalsan.retrofitwordpress._2 _2;
#SerializedName("3")
#Expose
private com.dkalsan.retrofitwordpress._3 _3;
public com.dkalsan.retrofitwordpress._1 get1() {
return _1;
}
public void set1(com.dkalsan.retrofitwordpress._1 _1) {
this._1 = _1;
}
public com.dkalsan.retrofitwordpress._2 get2() {
return _2;
}
public void set2(com.dkalsan.retrofitwordpress._2 _2) {
this._2 = _2;
}
public com.dkalsan.retrofitwordpress._3 get3() {
return _3;
}
public void set3(com.dkalsan.retrofitwordpress._3 _3) {
this._3 = _3;
}
}
_1.java (_2.java and _3.java are identical)
public class _1 {
#SerializedName("src")
#Expose
private String src;
#SerializedName("caption")
#Expose
private String caption;
public String getSrc() {
return src;
}
public void setSrc(String src) {
this.src = src;
}
public String getCaption() {
return caption;
}
public void setCaption(String caption) {
this.caption = caption;
}
}
The problem occurs in case the screenshots field contains no entries. I've set up the HttpLoggingInterceptor, which logs the response code 200 and the json in its entirety. I've also excluded the possibility of it being the internet connectivity issue according to the following article. If I remove the screenshots field from the model there is no trouble parsing. Is it possible that the error persists due to GSON trying to deserialize the nonexistent fields 1, 2, and 3 and if so, how to deal with it?
Turn out the problem was in the JSON response formatting. If there were no screenshots it was formatted as a JSON array, otherwise it was formatted as a JSON object containing objects 1, 2, 3, etc. I've managed to fix it by following the answer on this stackoverflow question.
Related
This question already has answers here:
Why does Gson fromJson throw a JsonSyntaxException: Expected BEGIN_OBJECT but was BEGIN_ARRAY?
(2 answers)
Closed 5 years ago.
with the next problem, when trying to consume a webservice, then message and presentation;
Expected BEGIN_ARRAY but was BEGIN_OBJECT
I'm not sure how to make a scenario, I've already got data from a webservice, but when it's not a simple array.
I have tried many alternatives, but without success.
response api
{
"_links": {
"self": {
"href": "http://url.com/service?page=1"
},
"first": {
"href": "http://url.com/service"
},
"last": {
"href": "http://url.com/service?page=1"
}
},
"_embedded": {
"data": [
{
"id": 1,
"nome": "teste",
"_links": {
"self": {
"href": "http://url.com/service/1"
}
}
},
{
"id": 2,
"nome": "teste 2",
"_links": {
"self": {
"href": "http://url.com/service/2"
}
}
}
]
},
"page_count": 1,
"page_size": 25,
"total_items": 2,
"page": 1
}
Client
public class ApiClient {
private static final String BASE_URL = "http://url.com/";
private static Retrofit getClient() {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();
Gson gson = new GsonBuilder().setLenient().create();
return new Retrofit.Builder()
.baseUrl(BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create(gson))
.build();
}
/**
* Get API Service
*
* #return API Service
*/
public static ApiInterface getApiService() {
return getClient().create(ApiInterface.class);
}
}
Interface
/**
* Class ApiInterface
*/
public interface ApiInterface
{
#Headers("Accept: application/json")
#GET("/service")
Call<ArrayList<ServiceData>> getData();
}
Service
public class Service{
#SerializedName("data")
private ArrayList<ServiceData> service = new ArrayList<>();
}
Service Data
public class ServiceData {
#SerializedName("id")
private int id;
public ServiceData(int id, String nome) {
this.id = id;
}
public int getId() {
return id;
}
}
Activity
final Call<ArrayList<ServiceData>> service = apiService.getService();
service.enqueue(new Callback<ArrayList<ServiceData>>() {
#Override
public void onResponse(Call<ArrayList<ServiceData>> call, Response<ArrayList<ServiceData>> response) {
Log.e(TAG, "" + response.body());
}
#Override
public void onFailure(Call<ArrayList<ServiceData>> call, Throwable t) {
Log.e(TAG, "" + t);
}
});
You were in the right path but the response is the whole json and not only the data part you want.
I would create the ResponseApi class:
public class ResponseApi {
#SerializedName("_embedded")
private Service embedded;
}
And change on ApiInterface:
Call<ArrayList<ServiceData>> getData();
To:
Call<ResponseApi> getData();
Also in your activity replace all ArrayList<ServiceData> with ResponseApi.
With only this changes your code should work. And then you'll need to add getters in ResponseApi and Service to access the saved data.
UPDATE adding some getters:
We need the possibility to get the ArrayList of ServiceData of services:
public class Service {
// Your current code
public List<ServiceData> getServices() {
return service;
}
}
And also we could create a getter in ResponseApi to get embedded getEmbedded (I'll add the code as info only) but since we only want the services we could create a getter to the list of services getEmbededServices and use this last method.
public class ResponseApi {
// Your current code
public Service getEmbedded() { // Not used, only shown as info
return embedded;
}
public List<ServiceData> getEmbeddedServices() {
return embedded.getServices();
}
}
This way, when you'll receive a ResponseApi object in the onResponse method you can call its getEmbeddedServices to get the List of ServiceData and then you can loop through them to get the ids:
#Override
public void onResponse(Call<ResponseApi> call, Response<ResponseApi> response) {
Log.d(TAG, "services: " + response.getEmbeddedServices());
// Here you can loop the response.getEmbeddedServices() which is a List of ServiceData and get each of the ids. Ex:
for (ServiceData serviceData : response.getEmbeddedServices()) {
Log.d(TAG, "service Id: " + serviceData.getId());
// Here you have access to the ids and can do whatever you need with them.
}
}
By the way, only as a suggestion, I would rename (with refactor in Android Studio) this service var (in Service class):
private ArrayList<ServiceData> service = new ArrayList<>();
To servicesList:
private ArrayList<ServiceData> servicesList = new ArrayList<>();
And maybe also refactor the Service class to ServicesList class.
It's going to work either you rename them or not but, in my opinion, the code is more readable this way.
Try this
Your Parsing mapping has issues try below Model
ServiceData.java
public class ServiceData {
#SerializedName("_links")
#Expose
private Links links;
#SerializedName("_embedded")
#Expose
private Embedded embedded;
#SerializedName("page_count")
#Expose
private Integer pageCount;
#SerializedName("page_size")
#Expose
private Integer pageSize;
#SerializedName("total_items")
#Expose
private Integer totalItems;
#SerializedName("page")
#Expose
private Integer page;
public Links getLinks() {
return links;
}
public void setLinks(Links links) {
this.links = links;
}
public Embedded getEmbedded() {
return embedded;
}
public void setEmbedded(Embedded embedded) {
this.embedded = embedded;
}
public Integer getPageCount() {
return pageCount;
}
public void setPageCount(Integer pageCount) {
this.pageCount = pageCount;
}
public Integer getPageSize() {
return pageSize;
}
public void setPageSize(Integer pageSize) {
this.pageSize = pageSize;
}
public Integer getTotalItems() {
return totalItems;
}
public void setTotalItems(Integer totalItems) {
this.totalItems = totalItems;
}
public Integer getPage() {
return page;
}
public void setPage(Integer page) {
this.page = page;
}
}
Self_.java
public class Self_ {
#SerializedName("href")
#Expose
private String href;
public String getHref() {
return href;
}
public void setHref(String href) {
this.href = href;
}
}
Self.java
public class Self {
#SerializedName("href")
#Expose
private String href;
public String getHref() {
return href;
}
public void setHref(String href) {
this.href = href;
}
}
Links_.java
public class Links_ {
#SerializedName("self")
#Expose
private Self_ self;
public Self_ getSelf() {
return self;
}
public void setSelf(Self_ self) {
this.self = self;
}
}
Links.java
public class Links {
#SerializedName("self")
#Expose
private Self self;
#SerializedName("first")
#Expose
private First first;
#SerializedName("last")
#Expose
private Last last;
public Self getSelf() {
return self;
}
public void setSelf(Self self) {
this.self = self;
}
public First getFirst() {
return first;
}
public void setFirst(First first) {
this.first = first;
}
public Last getLast() {
return last;
}
public void setLast(Last last) {
this.last = last;
}
}
Last.java
public class Last {
#SerializedName("href")
#Expose
private String href;
public String getHref() {
return href;
}
public void setHref(String href) {
this.href = href;
}
}
First.java
public class First {
#SerializedName("href")
#Expose
private String href;
public String getHref() {
return href;
}
public void setHref(String href) {
this.href = href;
}
}
Embedded.java
public class Embedded {
#SerializedName("data")
#Expose
private List<Datum> data = null;
public List<Datum> getData() {
return data;
}
public void setData(List<Datum> data) {
this.data = data;
}
}
Datum.java
public class Datum {
#SerializedName("id")
#Expose
private Integer id;
#SerializedName("nome")
#Expose
private String nome;
#SerializedName("_links")
#Expose
private Links_ links;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public Links_ getLinks() {
return links;
}
public void setLinks(Links_ links) {
this.links = links;
}
}
Try to remove ArrayList from every where and direct use ServiceData
Interface
/**
* Class ApiInterface
*/
public interface ApiInterface
{
#Headers("Accept: application/json")
#GET("/service")
Call<ServiceData> getData();
}
Service Data
public class ServiceData {
#SerializedName("id")
private int id;
public ServiceData(int id, String nome) {
this.id = id;
}
public int getId() {
return id;
}
}
Activity
final Call<ServiceData> service = apiService.getService();
service.enqueue(new Callback<ServiceData>() {
#Override
public void onResponse(Call<ServiceData> call, Response<ServiceData> response) {
Log.e(TAG, "" + response.body());
}
#Override
public void onFailure(Call<ServiceData> call, Throwable t) {
Log.e(TAG, "" + t);
}
});
You call and waiting for List. Call<ArrayList<ServiceData>>
But in the response, you have an object.
[...] - is array (list)
{...} - is object
You need to create classes for all parameters properly.
Just try to look at this service (or similar):
http://www.jsonschema2pojo.org/
Or Android Studio (IDEA) also has a plugin (GsonFormat) for converting JSON.
How to convert java object to xml using JAXB to get the following xml:
<Case>
<Version>1.0</Version>
<Code>457123</Code>
<Meta uc=\"Sample\" pip=\"116.0.1.1\" lot=\"P\"/>
</Case>
There are many answers regarding how to get XML. I have gone through all those. But my question is how to get the XML as what I have shown. It contains a self-closing tag which even contains attributes.
I am using Eclipse IDE. Please suggest a method.
This is my case class:
import auth.Res.Meta;
#XmlRootElement (name="Case")
public class Test {
private Meta mt;
private String version;
private String code;
#XmlRootElement
public class Meta {
#XmlAttribute
private String uc;
#XmlAttribute
private String pip;
public String getUc() {
return uc;
}
public void setUc(String uc) {
this.uc = uc;
}
public String getPip() {
return pip;
}
public void setPip(String pip) {
this.pip = pip;
}
}
public Meta getMt() {
return mt;
}
public void setMt(Meta mt) {
this.mt = mt;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
}
Solution:
I solved it by creating seperate class for Meta as suggested by LazerBanana in the first answer.
This is how your Meta class should look like.
public class Meta {
private String uc;
private String pip;
private String lot;
public String getUc() {
return uc;
}
#XmlAttribute
public void setUc(String uc) {
this.uc = uc;
}
public String getPip() {
return pip;
}
#XmlAttribute
public void setPip(String pip) {
this.pip = pip;
}
public String getLot() {
return lot;
}
#XmlAttribute
public void setLot(String lot) {
this.lot = lot;
}
}
this is your Case class which is the root element
#XmlRootElement
public class Case {
private int version;
private String code;
private String id;
private Meta meta;
public int getVersion() {
return version;
}
#XmlElement
public void setVersion(int version) {
this.version = version;
}
public String getCode() {
return code;
}
#XmlElement
public void setCode(String code) {
this.code = code;
}
public String getId() {
return id;
}
#XmlElement
public void setId(String id) {
this.id = id;
}
public Meta getMeta() {
return meta;
}
#XmlElement
public void setMeta(Meta meta) {
this.meta = meta;
}
}
And this is the marshaling bit to the console and to the file it you want.
public class Main {
public static void main(String... args) {
Case fcase = new Case();
Meta meta = new Meta();
meta.setLot("asd");
meta.setPip("sdafa");
meta.setUc("asgd4");
fcase.setMeta(meta);
fcase.setVersion(1);
fcase.setId("sah34");
fcase.setCode("code34");
try {
// File file = new File("C:\\file.xml");
JAXBContext jaxbContext = JAXBContext.newInstance(Case.class, Meta.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
// output pretty printed
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
// jaxbMarshaller.marshal(fcase, file);
jaxbMarshaller.marshal(fcase, System.out);
} catch (JAXBException e) {
e.printStackTrace();
}
}
}
Output:
<case>
<code>code34</code>
<id>sah34</id>
<meta lot="asd" pip="sdafa" uc="asgd4"/>
<version>1</version>
</case>
Next time please try to do more research i am not an expert and I just googled it.
https://www.mkyong.com/java/jaxb-hello-world-example/
i need to create a rest service which accepts xml of format i have gien. Thats y i need it in a single class.
#POST
#Path("/add")
#Consumes("application/xml")
#Produces("application/xml")
public Response getper(Test test)
{
String nam=test.getVersion();
int cd=test.getCode();
Res rs=new Res();
rs.setMessage(nam);
.
.
return Response.status(200).entity(rs).build();
}
Using Retrofit here to consume Google Civic API.
The library requires you to create a model of what the API will return as I have done already with Election. Which is basically a copy of the google documentation.
(Retrofit binds the response properties to properties with the same name)
Election.Java :
public class Election {
private long id;
private String name;
private String electionDay;
private String ocdDivisionId;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getElectionDay() {
return electionDay;
}
public void setElectionDay(String electionDay) {
this.electionDay = electionDay;
}
public String getOcdDivisionId() {
return ocdDivisionId;
}
public void setOcdDivisionId(String ocdDivisionId) {
this.ocdDivisionId = ocdDivisionId;
}
}
But Representatives have an inconsistent property name, thus I don't see a way to model this in a way Retrofit will know how to deserialize the API's response.
Representatives object (JSON) :
property name is called (key)
How do I let Retrofit deserialize a model that captures the property named variable after a key of the division?
Assuming you're using a Gson converter, I personally would use a map. I guess the same can be achieved with other converters, but I never used them. Say you have the following object:
public class Division {
#SerializedName("name")
#Expose
private String name;
#SerializedName("alsoKnownAs")
#Expose
private List<String> alsoKnownAs = new ArrayList<>();
#SerializedName("officeIndices")
#Expose
private List<Integer> officeIndices = new ArrayList<>();
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<String> getAlsoKnownAs() {
return alsoKnownAs;
}
public void setAlsoKnownAs(List<String> alsoKnownAs) {
this.alsoKnownAs = alsoKnownAs;
}
public List<Integer> getOfficeIndices() {
return officeIndices;
}
public void setOfficeIndices(List<Integer> officeIndices) {
this.officeIndices = officeIndices;
}
}
Which represents the object inside the divisions array. You can then have the class:
private class Divisions {
#SerializedName("divisions")
#Expose
private Map<String, Division> divisions = new HashMap<>();
// ...
}
Notice the usage of a map here? Behind the scenes Gson will be able to serialise and deserialise your objects. The class Divisions is the root of the json you gave us in the question.
Hope this helps
I am trying to assign the value returned by some function to a field in the deserialized class of json.
FileInfo.java
public class FileInfo {
#SerializedName("Name")
private String mName;
#SerializedName("Url")
private String mUri;
#SerializedName("Size")
private Integer mSize;
#SerializedName("ModTime")
private Long mModifiedTime;
private FileType mType;
#SerializedName("Children")
private ArrayList<FileInfo> mChildren = new ArrayList<>();
public ArrayList<FileInfo> getChildren() {
return mChildren;
}
public long getModifiedTime() {
return mModifiedTime;
}
public String getName() {
return mName;
}
public Integer getSize() {
return mSize;
}
public String getUrl() {
return mUri;
}
public FileType getType() {
return mType;
}
public void setChildren(ArrayList<FileInfo> mChildren) {
this.mChildren = mChildren;
}
public void setModifiedTime(long mModifiedTime) {
this.mModifiedTime = mModifiedTime;
}
public void setName(String mName) {
this.mName = mName;
}
public void setSize(Integer mSize) {
this.mSize = mSize;
}
public void setType(FileType mType) {
this.mType = mType;
}
public void setUri(String mUri) {
this.mUri = mUri;
}
#Override
public String toString() {
return FileInfo.class.toString();
}
public FileInfo() {
}
}
The mType needs to be assigned to foo(mName). I looked up custom deserializers and instance creators but none of those helped. I also thought of TypeAdapters which i feel defeats the purpose of keeping deserialization(using GSON) simple.
This is a sample JSON string that will be deserialized.
[
{
"Name":"Airport",
"Url":"http://192.168.2.2/api/sites/Baltimore%20Airport/Airport",
"Size":0,
"ModTime":"2015-12-02T14:19:17.29824-05:00",
"Children":null
}
]
P.S. I'm not sure if this should be done during deserialization but trying anyways. Also please let me know of alternative ways to achieve this.
I'm being given a Json file with the form:
{
"descriptions": {
"desc1": "someString",
"desc2": {"name":"someName", "val": 7.0}
}
}
I have the POJO:
public class CustomClass {
Map<String, Object> descriptions;
public static class NameVal{
String name;
double val;
public NameVal(String name, double val){...}
}
}
I can recreate the json file with the code:
CustomClass a = new CustomClass();
a.descriptions = new HashMap<String, Object>();
a.descriptions.put("desc1", "someString");
a.descriptions.put("desc2", new CustomClass.NameVal("someName", 7.0));
new ObjectMapper().writeValue(new File("testfile"), a);
But, when I read the object back in using:
CustomClass fromFile = new ObjectMapper().readValue(new File("testfile"), CustomClass.class);
then fromFile.descriptions.get("desc2") is of type LinkedHashMap instead of type CustomClass.NameVal.
How can I get Jackson to properly parse the type of the CustomClass.NameVal descriptors (other than making some class that wraps the parsing and explicitly converts the LinkedHashMap after Jackson reads the file)?
Try this. Create a class Description with name and value attributes:
public class Description {
private String name;
private double val;
}
Now in your CustomClass do this:
public class CustomClass {
List<Description> descriptions;
}
And that's it. Remember to create getters and setters because Jackson needs it.
You could try something like this:
public class DescriptionWrapper {
private Description descriptions;
public Description getDescriptions() {
return descriptions;
}
public void setDescriptions(Description descriptions) {
this.descriptions = descriptions;
}
}
public class Description {
private String desc1;
private NameValue desc2;
public String getDesc1() {
return desc1;
}
public void setDesc1(String desc1) {
this.desc1 = desc1;
}
public NameValue getDesc2() {
return desc2;
}
public void setDesc2(NameValue desc2) {
this.desc2 = desc2;
}
}
public class NameValue {
private String name;
private double val;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getVal() {
return val;
}
public void setVal(double val) {
this.val = val;
}
}