Develop Reference

How to insert RealmList to RealmDB

I am trying to insert realm lists to my realmdb in my first insert there is no problem but when I insert another realmList with a different class, my old values are deleted. So how can I insert a realmlist to DB? inserts are done separately.
RealmList<Product> insertedProduct = new RealmList<Product>();
RealmList<ProductSubCategory> insertedSubCategory = new RealmList<ProductSubCategory>();
RealmList<ProductMainCategory> insertedMainCategory = new RealmList<ProductMainCategory>();
... inserting to realm list firt time ...
insertRealmList(insertedProduct); //inserting to realmDB first time
insertRealmList(insertedSubCategory); //inserting to realmDB first time
insertRealmList(insertedMainCategory); //inserting to realmDB first time
first insert to realmDB
RealmList insert function
private void insertRealmList(final RealmList realmObject) {
mRealm = Realm.getDefaultInstance();
realmTask = mRealm.executeTransactionAsync(
new Realm.Transaction() {
#Override
public void execute(Realm realm) {
realm.copyToRealmOrUpdate(realmObject);
}
},
new Realm.Transaction.OnSuccess() {
#Override
public void onSuccess() {
Log.i(TAG, "onSuccess: successfully inserted data");
}
},
new Realm.Transaction.OnError() {
#Override
public void onError(Throwable error) {
Log.i(TAG, "onError: error while inserting " + "error: " + error);
}
}
);
}
... inserting to realm list second time...
insertRealmList(insertedLanguages); //insert realmDB second time
second insert to realmDB
PRODUCT MODEL
package Model;
import io.realm.RealmList;
import io.realm.RealmObject;
import io.realm.annotations.Ignore;
import io.realm.annotations.Index;
import io.realm.annotations.PrimaryKey;
public class Product extends RealmObject {
#PrimaryKey
#Index
private int ID;
#Index
private int PLU_NO;
private String PRODUCT_NAME;
private String MAIN_CATEGORY;
private String SUB_CATEGORY;
private String TYPE;
private String TUS;
private Double PRICE;
private String CALORIE;
private String COOKING_TIME;
private RealmList<String> PRODUCT_NAME_LANGUAGES;
private RealmList<String> PRODUCT_DESCRIPTION_LANGUAGES;
private String IMAGE_BASE_HORIZONTAL; //4/3
private String IMAGE_BASE_VERTICAL; //16/9
private String VIDEO_NAME; //video name
#Ignore
private int AMOUNT;
#Ignore
private int WINDOW_AMOUNT = 1;
public Product(int ID, int PLU_NO, String PRODUCT_NAME, String MAIN_CATEGORY, String SUB_CATEGORY, String TYPE, String TUS, Double PRICE, String CALORIE, String COOKING_TIME, RealmList<String> PRODUCT_NAME_LANGUAGES, RealmList<String> PRODUCT_DESCRIPTION_LANGUAGES, String IMAGE_BASE_HORIZONTAL, String IMAGE_BASE_VERTICAL, String VIDEO_NAME) {
this.ID = ID;
this.PLU_NO = PLU_NO;
this.PRODUCT_NAME = PRODUCT_NAME;
this.MAIN_CATEGORY = MAIN_CATEGORY;
this.SUB_CATEGORY = SUB_CATEGORY;
this.TYPE = TYPE;
this.TUS = TUS;
this.PRICE = PRICE;
this.CALORIE = CALORIE;
this.COOKING_TIME = COOKING_TIME;
this.PRODUCT_NAME_LANGUAGES = PRODUCT_NAME_LANGUAGES;
this.PRODUCT_DESCRIPTION_LANGUAGES = PRODUCT_DESCRIPTION_LANGUAGES;
this.IMAGE_BASE_HORIZONTAL = IMAGE_BASE_HORIZONTAL;
this.IMAGE_BASE_VERTICAL = IMAGE_BASE_VERTICAL;
this.VIDEO_NAME = VIDEO_NAME;
}
public Product() {
}
public int getID() {
return ID;
}
public void setID(int ID) {
this.ID = ID;
}
public int getPLU_NO() {
return PLU_NO;
}
public void setPLU_NO(int PLU_NO) {
this.PLU_NO = PLU_NO;
}
public String getPRODUCT_NAME() {
return PRODUCT_NAME;
}
public void setPRODUCT_NAME(String PRODUCT_NAME) {
this.PRODUCT_NAME = PRODUCT_NAME;
}
public String getMAIN_CATEGORY() {
return MAIN_CATEGORY;
}
public void setMAIN_CATEGORY(String MAIN_CATEGORY) {
this.MAIN_CATEGORY = MAIN_CATEGORY;
}
public String getSUB_CATEGORY() {
return SUB_CATEGORY;
}
public void setSUB_CATEGORY(String SUB_CATEGORY) {
this.SUB_CATEGORY = SUB_CATEGORY;
}
public String getTYPE() {
return TYPE;
}
public void setTYPE(String TYPE) {
this.TYPE = TYPE;
}
public String getTUS() {
return TUS;
}
public void setTUS(String TUS) {
this.TUS = TUS;
}
public Double getPRICE() {
return PRICE;
}
public void setPRICE(Double PRICE) {
this.PRICE = PRICE;
}
public String getCALORIE() {
return CALORIE;
}
public void setCALORIE(String CALORIE) {
this.CALORIE = CALORIE;
}
public String getCOOKING_TIME() {
return COOKING_TIME;
}
public void setCOOKING_TIME(String COOKING_TIME) {
this.COOKING_TIME = COOKING_TIME;
}
public RealmList<String> getPRODUCT_NAME_LANGUAGES() {
return PRODUCT_NAME_LANGUAGES;
}
public void setPRODUCT_NAME_LANGUAGES(RealmList<String> PRODUCT_NAME_LANGUAGES) {
this.PRODUCT_NAME_LANGUAGES = PRODUCT_NAME_LANGUAGES;
}
public RealmList<String> getPRODUCT_DESCRIPTION_LANGUAGES() {
return PRODUCT_DESCRIPTION_LANGUAGES;
}
public void setPRODUCT_DESCRIPTION_LANGUAGES(RealmList<String> PRODUCT_DESCRIPTION_LANGUAGES) {
this.PRODUCT_DESCRIPTION_LANGUAGES = PRODUCT_DESCRIPTION_LANGUAGES;
}
public String getIMAGE_BASE_HORIZONTAL() {
return IMAGE_BASE_HORIZONTAL;
}
public void setIMAGE_BASE_HORIZONTAL(String IMAGE_BASE_HORIZONTAL) {
this.IMAGE_BASE_HORIZONTAL = IMAGE_BASE_HORIZONTAL;
}
public String getIMAGE_BASE_VERTICAL() {
return IMAGE_BASE_VERTICAL;
}
public void setIMAGE_BASE_VERTICAL(String IMAGE_BASE_VERTICAL) {
this.IMAGE_BASE_VERTICAL = IMAGE_BASE_VERTICAL;
}
public String getVIDEO_NAME() {
return VIDEO_NAME;
}
public void setVIDEO_NAME(String VIDEO_NAME) {
this.VIDEO_NAME = VIDEO_NAME;
}
public int getAMOUNT() {
return AMOUNT;
}
public void setAMOUNT(int AMOUNT) {
this.AMOUNT = AMOUNT;
}
public int getWINDOW_AMOUNT() {
return WINDOW_AMOUNT;
}
public void setWINDOW_AMOUNT(int WINDOW_AMOUNT) {
this.WINDOW_AMOUNT = WINDOW_AMOUNT;
}
public void setDEFAULT_WINDOW_AMOUNT() {
this.WINDOW_AMOUNT = 1;
}
}
LANGUAGE MODEL
package Model;
import io.realm.RealmObject;
public class Language extends RealmObject {
#PrimaryKey
#Index
private int ID;
private String ICON;
private String NAME;
public Language(){
}
public Language(int ID, String ICON, String NAME) {
this.ID = ID;
this.ICON = ICON;
this.NAME = NAME;
}
public int getId() {
return ID;
}
public void setId(int id) {
this.ID = id;
}
public String getICON() {
return ICON;
}
public void setICON(String ICON) {
this.ICON = ICON;
}
public String getName() {
return NAME;
}
public void setName(String name) {
this.NAME = name;
}
}
Other two models are similar with product.

Please try the following method:
private <T extends RealmModel> void insertRealmList(final List<T> objects) {
try (Realm realmInstance = Realm.getDefaultInstance()) {
realmInstance.executeTransaction(realm -> {
for (T object : objects) {
realmInstance.insertOrUpdate(object);
}
});
}
}
Hope this helps!

Two ArrayList compare and update one Arraylist or overwrite in android?

I have two Arraylist.
ArrayList<Thumbnail> videoList = new ArrayList<>();
List<Giphy> giphyList = new ArrayList<>();
How to Compare two Arraylist and update List<Giphy> data in ArrayList<Thumbnail> or another third Arraylist or overwrite in List data in ArrayList<Thumbnail>?
Here Two Class Thumbnail and Giphy. Giphy class is compare to Thumbnail. Giphy Class data stored in Arraylist and Arraylist data Update in ArrayList or data overwrite in ArrayList.
class Thumbnail{
private String gif,videoUrl;
private int id, thumbUp, thumbDown;
public Thumbnail (int id,String gif,String videoUrl,int thumbUp,int thumbDown){
this.gif = gif;
this.videoUrl = videoUrl;
}
public String getGif() {
return gif;
}
public void setGif(String gif) {
this.gif = gif;
}
public String getVideoUrl() {
return videoUrl;
}
public void setVideoUrl(String videoUrl) {
this.videoUrl = videoUrl;
}
public int getId() {
return id;
}
public int getThumbUp() {
return thumbUp;
}
public int getThumbDown() {
return thumbDown;
}
public void setId(int id) {
this.id = id;
}
public void setThumbUp(int thumbUp) {
this.thumbUp = thumbUp;
}
public void setThumbDown(int thumbDown) {
this.thumbDown = thumbDown;
}
}
}
#Entity
Class Giphy{
#Id
private long id;
private String url;
private int thumbUp;
private int thumbDown;
public Giphy(){
}
public Giphy(long id,String url,int thumbUp,int thumbDown){
this.id = id;
this.url = url;
this.thumbUp = thumbUp;
this.thumbDown = thumbDown;
}
public long getId() {
return id;
}
public String getUrl() {
return url;
}
public int getThumbUp() {
return thumbUp;
}
public int getThumbDown() {
return thumbDown;
}
public void setId(long id) {
this.id = id;
}
public void setUrl(String url) {
this.url = url;
}
public void setThumbUp(int thumbUp) {
this.thumbUp = thumbUp;
}
public void setThumbDown(int thumbDown) {
this.thumbDown = thumbDown;
}
}

Android Nested Objects and Retrofit2

I am reading a JSON like this:
{
"matches": [{
"id": 246119,
"utcDate": "2018-08-17T18:15:00Z",
"status": "FINISHED",
"homeTeam": {
"id": 298,
"name": "Girona FC"
},
"awayTeam": {
"id": 250,
"name": "Real Valladolid CF"
},
"score": {
"winner": "DRAW",
"duration": "REGULAR"
}
}]
}
I must say that the JSON is valid. I am consuming this JSON through an API. I can correctly read the properties "id", "utc" and "status", but I could not with "score", "awayTeam" and "homeTeam". I don't really know how to work those properties. I'd like to handle each propertie of score, awayTeam, and homeTeam individually, for example, I want to get just the name of awayTeam and homeTeam and the 2 properties of score.
This, is my code:
MainActivity
public class MainActivity extends AppCompatActivity {
private Retrofit retrofit;
private static final String TAG = "Football";
private RecyclerView recyclerView;
private ListaPartidosAdapter listaPartidosAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView)findViewById(R.id.recyclerView);
listaPartidosAdapter = new ListaPartidosAdapter(this);
recyclerView.setAdapter(listaPartidosAdapter);
recyclerView.setHasFixedSize(true);
final LinearLayoutManager layoutManager = new LinearLayoutManager(this, VERTICAL, true);
recyclerView.setLayoutManager(layoutManager);
retrofit = new Retrofit.Builder()
.baseUrl("http://api.football-data.org/v2/")
.addConverterFactory(GsonConverterFactory.create())
.build();
obtenerDatos();
}
private void obtenerDatos() {
footballdataService service = retrofit.create(footballdataService.class);
Call<PartidosRespuesta> partidosRespuestaCall = service.obtenerlistaPartidos();
partidosRespuestaCall.enqueue(new Callback<PartidosRespuesta>() {
#Override
public void onResponse(Call<PartidosRespuesta> call, Response<PartidosRespuesta> response) {
if(response.isSuccessful()) {
PartidosRespuesta partidosRespuesta = response.body();
ArrayList<Partido> listaPartidos = partidosRespuesta.getMatches();
listaPartidosAdapter.adicionarListaPartidos(listaPartidos);
}
else {
Log.e(TAG, "onResponse: " + response.errorBody());
}
}
#Override
public void onFailure(Call<PartidosRespuesta> call, Throwable t) {
Log.e(TAG, "onFailure: " + t.getMessage());
}
});
}
}
Now this is my interface. footballdataService
public interface footballdataService {
#GET("competitions/2014/matches")
Call<PartidosRespuesta> obtenerlistaPartidos();
}
This is PartidosRespuestas class
public class PartidosRespuesta {
private ArrayList<Partido> matches;
public ArrayList<Partido> getMatches() {
return matches;
}
public void setMatches(ArrayList<Partido> matches) {
this.matches = matches;
}
}
This, is the adapter.
public class ListaPartidosAdapter extends RecyclerView.Adapter<ListaPartidosAdapter.ViewHolder> {
private static final String TAG = "Football_Adapter";
private ArrayList<Partido> dataset;
private Context context;
public ListaPartidosAdapter(Context context) {
this.context = context;
dataset = new ArrayList<Partido>();
}
#Override
public ListaPartidosAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_partidos, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ListaPartidosAdapter.ViewHolder holder, int position) {
Partido p = dataset.get(position);
holder.status.setText(p.getId());
}
#Override
public int getItemCount() {
return dataset.size();
}
public void adicionarListaPartidos(ArrayList<Partido> listaPartidos){
dataset.addAll(listaPartidos);
notifyDataSetChanged();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView status;
public ViewHolder(View itemView) {
super(itemView);
status = (TextView) itemView.findViewById(R.id.status);
}
}
}
And this.., is Partido class
public class Partido {
private String id;
private String utcDate;
private String status;
private EquipoCasa homeTeam;
private EquipoVisita AwayTeam;
private Puntaje score;
public String getId() {
return id;
}
public String getUtcDate() {
return utcDate;
}
public String getStatus() {
return status;
}
public EquipoCasa getHomeTeam() {
return homeTeam;
}
public EquipoVisita getAwayTeam() {
return AwayTeam;
}
public Puntaje getScore() {
return score;
}
public void setId(String id) {
this.id = id;
}
public void setUtcDate(String utcDate) {
this.utcDate = utcDate;
}
public void setStatus(String status) {
this.status = status;
}
public void setHomeTeam(EquipoCasa homeTeam) {
this.homeTeam = homeTeam;
}
public void setAwayTeam(EquipoVisita awayTeam) {
AwayTeam = awayTeam;
}
public void setScore(Puntaje score) {
this.score = score;
}
public class EquipoCasa {
private String id;
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
public class EquipoVisita {
private String id;
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
public class Puntaje {
private String winner;
private String duration;
public String getWinner() {
return winner;
}
public void setWinner(String winner) {
this.winner = winner;
}
public String getDuration() {
return duration;
}
public void setDuration(String duration) {
this.duration = duration;
}
}
}

POJO classes of your code should this:
AwayTeam.java
//AwayTeam
public class AwayTeam {
#SerializedName("id")
#Expose
private Integer id;
#SerializedName("name")
#Expose
private String name;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
PartidosRespuesta.java
//Object response
public class PartidosRespuesta {
#SerializedName("matches")
#Expose
private List<Match> matches = null;
public List<Match> getMatches() {
return matches;
}
public void setMatches(List<Match> matches) {
this.matches = matches;
}
}
HomeTeam.java
//HomeTeam
public class HomeTeam {
#SerializedName("id")
#Expose
private Integer id;
#SerializedName("name")
#Expose
private String name;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Score.java
//Score
public class Score {
#SerializedName("winner")
#Expose
private String winner;
#SerializedName("duration")
#Expose
private String duration;
public String getWinner() {
return winner;
}
public void setWinner(String winner) {
this.winner = winner;
}
public String getDuration() {
return duration;
}
public void setDuration(String duration) {
this.duration = duration;
}
}
Edit:
#Override
public void onBindViewHolder(ListaPartidosAdapter.ViewHolder holder, int position) {
Partido p = dataset.get(position);
HomeTeam homeTeam = p.getHomeTeam();
String nameHomeTeam = homeTeam.getName();
}
And tool convert json to java code: http://www.jsonschema2pojo.org/

try
public class Puntaje {
public String winner;
public String duration;
}

It's seems like you've problems with your models. Use this link to convert your json to java object.

Nested object in Json

This is my JSON:
I need to access to extra_services and get the service_name.
I know I can do it directly using Gson but the problem is that I need to use getters and setters because I'm using an adapter inside of a recycler, how can I do that?
here is my adapter class where I need to get the service name
public class ExtraServicesAdapter extends RecyclerView.Adapter<ExtraServicesAdapter.ViewHolder> implements View.OnClickListener
{
private ArrayList<Business> businessList;
private Activity activity;
private int layoutMolde,idb;
public ExtraServicesAdapter(Activity activity, ArrayList<Business> list, int layout)
{
this.activity = activity;
this.businessList = list;
layoutMolde = layout;
}
#Override
public ExtraServicesAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_services_basic, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position)
{
if(businessList.get(position).getExtra_services()==null)
{
holder.txtNameServiceBasic.setText("There's nothing to show");
}
holder.txtNameServiceBasic.setText(businessList.get(position).getExtra_services());
}
#Override
public int getItemCount()
{
return businessList.size();
}
#Override
public void onClick(View v)
{
}
public class ViewHolder extends RecyclerView.ViewHolder
{
public TextView txtNameServiceBasic;
public ViewHolder( View itemView)
{
super(itemView);
txtNameServiceBasic = (TextView) itemView.findViewById(R.id.txtNameServiceBasic);
}
}
}
and this is my class where are the getters and setters that I'm using
public class Business {
private Integer id,rating;
private String name, description, cover_url_string, logo_url_string, icon_default,business_name,cover_default,extra_services;
private Boolean status;
public Business(){}
public Business(Integer id,Integer rating,String business_name, String name, String description, String logo_url_string, String cover_default, String icon_default,String cover_url_string,String extra_services) {
this.id = id;
this.name = name;
this.business_name=business_name;
this.description = description;
this.logo_url_string = logo_url_string;
this.cover_url_string = cover_url_string;
this.rating=rating;
this.icon_default=icon_default;
this.cover_default=cover_default;
this.extra_services=extra_services;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getRating() {
return rating;
}
public String getBusiness_name() {
return business_name;
}
public void setBusiness_name(String business_name) {
this.business_name = business_name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLogo_url_string() {
return logo_url_string;
}
public void setLogo_url_string(String logo_url_string) {
this.logo_url_string = logo_url_string;
}
public String getIcon_default() {
return icon_default;
}
public String getCover_default() {
return cover_default;
}
public String getCover_url_string() {
return cover_url_string;
}
public String getExtra_services() {
return extra_services;
}
public void setExtra_services() {
this.extra_services=extra_services;
}
}

You can add an ExtraServices class that contains a list of ExtraService
ExtraService
public class ExtraService {
private String Id;
private String ServiceName;
public String getId() {
return Id;
}
public void setId(String Id) {
this.Id = Id;
}
public String getServiceName() {
return ServiceName;
}
public void setServiceName(String ServiceName) {
this.ServiceName = ServiceName;
}
ExtraServices
public class ExtraServices {
private List<ExtraService> extraServicesList;
public List<ExtraService> getExtraServicesList() {
return extraServicesList;
}
public void setExtraServicesList(List<ExtraService> extraServicesList) {
this.extraServicesList = extraServicesList;
}
public void add(ExtraService extraService){
if(extraServicesList == null){
extraServicesList = new ArrayList<>();
}
extraServicesList.add(extraService);
}
And in your Business class add getters and setters of ExtraServices
private ExtraServices extraServices;
public ExtraServices getExtraServices () {
return extraServices;
}
public void setExtraServices (ExtraServices extraServices) {
this.extraServices = extraServices;
}
After you have to do the setter process and in your Adapter you should do something like this:
holder.txtNameServiceBasic.setText(businessList.get(position).getExtraServices().getExtraServicesList().get(posistion).getServiceName());

Retrofit Returns Null value

I'm new to Android networking. I'm unable to figure out why I'm getting null value for the phonone
This is a sample of JSON data:
{
"columns":{ <some data here> },
"rows":[
{
"timestamp":"28/08/2016 14:11:46",
"name":"Mohammed Sohail",
"phoneno.":8142629002,
"event-name":"Roadies",
"branch":"IT",
"year":3
},
{
"timestamp":"28/08/2016 14:13:03",
"name":"Shaik Asaduddin",
"phoneno.":8143026049,
"event-name":"Ted talk",
"branch":"IT",
"year":3
}
}
I'm able to get every value inside row array except "phoneno" it gives me null value
Here are my classes
Registration class:
public class Registration {
private Columns columns;
private List<Row> rows = null;
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
public Columns getColumns() {
return columns;
}
public void setColumns(Columns columns) {
this.columns = columns;
}
public List<Row> getRows() {
return rows;
}
public void setRows(List<Row> rows) {
this.rows = rows;
}
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
}
Row class:
public class Row {
private String timestamp;
private String name;
private String phoneno;
private String eventName;
private String branch;
private String year;
public String getTimestamp() {
return timestamp;
}
public void setTimestamp(String timestamp) {
this.timestamp = timestamp;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhoneno() {
return phoneno;
}
public void setPhoneno(String phoneno) {
this.phoneno = phoneno;
}
public String getEventName() {
return eventName;
}
public void setEventName(String eventName) {
this.eventName = eventName;
}
public String getBranch() {
return branch;
}
public void setBranch(String branch) {
this.branch = branch;
}
public String getYear() {
return year;
}
public void setYear(String year) {
this.year = year;
}
}
and here is the adapter I'm using to set the text view's
public class RegistrationAdapter extends RecyclerView.Adapter<RegistrationAdapter.RegistrationViewHolder> {
private List<Row> rows;
private Context context;
private int rowLayout;
public RegistrationAdapter(List<Row> rows) {
this.rows=rows;
}
#Override
public RegistrationAdapter.RegistrationViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.registration_item_view, parent, false);
return new RegistrationViewHolder(view);
}
#Override
public void onBindViewHolder(RegistrationViewHolder holder, int position) {
holder.studentName.setText(rows.get(position).getName());
holder.studentPhone.setText(String.valueOf(rows.get(position).getPhoneno()));
holder.studentBranch.setText(rows.get(position).getBranch());
holder.studentYear.setText(rows.get(position).getYear());
}
#Override
public int getItemCount() {
return rows.size();
}
public class RegistrationViewHolder extends RecyclerView.ViewHolder {
LinearLayout studentLayout;
TextView studentName;
TextView studentPhone;
TextView studentBranch;
TextView studentYear;
public RegistrationViewHolder(View itemView) {
super(itemView);
studentLayout=(LinearLayout)itemView.findViewById(R.id.studentLayout);
studentName=(TextView)itemView.findViewById(R.id.studentName);
studentPhone=(TextView)itemView.findViewById(R.id.studentPhoneNumber);
studentBranch=(TextView)itemView.findViewById(R.id.studentBranch);
studentYear=(TextView)itemView.findViewById(R.id.studentYear);
}
}
public RegistrationAdapter( List<Row> rows, int rowLayout,Context context) {
this.rows = rows;
this.rowLayout = rowLayout;
this.context = context;
}
}

Maybe is a typo but in your json you have "phoneno." and your row class specifies phoneno.

you can you use jsonschema2pojo to genenare class from json object.