Develop Reference

Getting context from ViewModel in testing

So I have ViewModel with a method to get data using context. But in testing the data is null because possibly there is no context when testing.
The code is as follow:
This is testing ViewModel code
public class FilmViewTest {
private FilmView filmView;
#Before
public void setUp() {
Application context = Mockito.mock(Application.class);
filmView = new FilmView(context);
FilmData filmData = new FilmData(context);
}
// ubah poster menjadi link
#Test
public void getFilms() {
List<ResultsItem> films = filmView.getFilms();
assertNotNull(films);
assertEquals(10, films.size());
}
}
and here is the ViewModel itself
public class FilmView extends AndroidViewModel {
public FilmView(#NonNull Application application) {
super(application);
}
private Context context = getApplication().getApplicationContext();
private FilmData filmData = new FilmData(context);
public List<ResultsItem> getFilms() {
return FilmData.generateFilms();
}
}
the data class
public class FilmData {
private static Context context;
public FilmData(Context context) {
FilmData.context = context;
}
public static ArrayList<ResultsItem> generateFilms() {
ArrayList<ResultsItem> courses = new ArrayList<>();
courses.add(new ResultsItem(
"A Star is Born",
"Seasoned musician Jackson Maine discovers — " +
"and falls in love with — struggling artist Ally." +
" She has just about given up on her dream to make it big as a singer — until Jack coaxes her into the spotlight. But even as Ally's career takes off, the personal " +
"side of their relationship is breaking down, as Jack fights an ongoing battle with his own internal demons.",
context.getResources().getDrawable(R.drawable.poster_a_start_is_born),
346, " February 19, 2019", 75, 50));
courses.add(new ResultsItem("Aquaman",
"Once home to the most advanced civilization on Earth, Atlantis is now an underwater kingdom ruled by the power-hungry King Orm. With a vast army at his disposal, Orm plans to conquer the remaining oceanic people and then the surface world. " +
"Standing in his way is Arthur Curry, Orm's half-human, " +
"half-Atlantean brother and true heir to the throne.",
context.getResources().getDrawable(R.drawable.poster_aquaman),
238, "December 21, 2018", 68, 60));
courses.add(new ResultsItem("Bohemian Rhapsody ",
"Singer Freddie Mercury, guitarist Brian May, drummer Roger Taylor and bass guitarist John Deacon take the music world by storm when they form the rock 'n' roll band Queen in 1970. Hit songs become instant classics. When Mercury's increasingly wild lifestyle starts to spiral out of control, " +
"Queen soon faces its greatest challenge yet – " +
"finding a way to keep the band together amid the success and excess.",
context.getResources().getDrawable(R.drawable.poster_bohemian),
892, "November 2, 2018", 80, 299));
courses.add(new ResultsItem("Alita: Battle Angel ",
"When Alita awakens with no memory of who she is in a future world she does not recognize, she is taken in by Ido, a compassionate doctor who realizes that" +
" somewhere in this abandoned cyborg " +
"shell is the heart and soul of a young woman with an extraordinary past.\n",
context.getResources().getDrawable(R.drawable.poster_alita),
289, "January 31, 2019", 69, 15 ));
courses.add(new ResultsItem(
"Cold Pursuit",
"The quiet family life of Nels Coxman, a snowplow driver, is upended after his son's murder. Nels begins a vengeful hunt for Viking, the drug lord he holds responsible for the killing, eliminating Viking's associates one by one. As Nels draws closer to Viking, his actions bring even more unexpected and violent consequences, as he proves that revenge is all in the execution.",
context.getResources().getDrawable(R.drawable.poster_cold_persuit),
54, "February 7, 2019", 54, 219));
courses.add(new ResultsItem(
"Creed",
"The former World Heavyweight Champion Rocky Balboa serves as a trainer and mentor to Adonis Johnson, the son of his late friend and former rival Apollo Creed.",
context.getResources().getDrawable(R.drawable.poster_creed),
129, "November 25, 2015", 73, 281));
courses.add(new ResultsItem("Fantastic Beasts: The Crimes of Grindelwald",
"Gellert Grindelwald has escaped imprisonment and has begun gathering followers to his cause—elevating wizards above all non-magical beings. The only one capable of putting a stop to him is the wizard he once called his closest friend, Albus Dumbledore. However, Dumbledore will need to seek help from the wizard who had thwarted Grindelwald once before, his former student Newt Scamander, who agrees to help, unaware of the dangers that lie ahead. Lines are drawn as love and loyalty are tested, even among the truest friends and family, in an increasingly divided wizarding world.",
context.getResources().getDrawable(R.drawable.poster_crimes),
123, "November 14, 2018", 69, 210));
courses.add(new ResultsItem("Glass ",
"In a series of escalating encounters, former security guard David Dunn uses his supernatural abilities to track Kevin Wendell Crumb, a disturbed man who has twenty-four personalities. Meanwhile, the shadowy presence of Elijah Price emerges as an orchestrator who holds secrets critical to both men.",
context.getResources().getDrawable(R.drawable.poster_glass).getCurrent(),
213, "January 16, 2019", 66, 190));
courses.add(new ResultsItem("How to Train Your Dragon ",
"As the son of a Viking leader on the cusp of manhood, shy Hiccup Horrendous Haddock III faces a rite of passage: he must kill a dragon to prove his warrior mettle. But after downing a feared dragon, he realizes that he no longer wants to destroy it, and instead befriends the beast – which he names Toothless – much to the chagrin of his warrior father",
context.getResources().getDrawable(R.drawable.poster_how_to_train),
319, "March 10, 2010", 77, 219));
courses.add(new ResultsItem(
"Avengers: Infinity War",
"As the Avengers and their allies have continued to protect the world from threats too large for any one hero to handle, a new danger has emerged from the cosmic shadows: Thanos. A despot of intergalactic infamy, his goal is to collect all six Infinity Stones, artifacts of unimaginable power, and use them to inflict his twisted will on all of reality. Everything the Avengers have fought for has led up to this moment - the fate of Earth and existence itself has never been more uncertain.",
context.getResources().getDrawable(R.drawable.poster_infinity_war),
193, "April 25, 2018", 83, 21933));
return courses;
}
}
it gives null error on the methods
java.lang.NullPointerException
at com.example.movietv.film.utils.FilmData.generateFilms(FilmData.java:28)
at com.example.movietv.film.adapter.FilmView.getFilms(FilmView.java:26)
at com.example.movietv.film.adapter.FilmViewTest.getFilms(FilmViewTest.java:32)
Any help would be appreciated! Thanks!

Ideally, you should not be passing entire drawable object into model context.getResources().getDrawable(R.drawable.poster_infinity_war). Instead, just pass the int of the resource as
new ResultsItem("How to Train Your Dragon ",
"As ... father", R.drawable.poster_how_to_train,
319, "March 10, 2010", 77, 219)
Note: You need to change ResultsItem Model accordingly
and then, when you are actually rendering it in an Adapter:
public class MyOrdersAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<MyOrder> restaurantList;
private Context context;
public MyOrdersAdapter(Context context, List<MyOrder> restaurantList) {
this.context = context;
this.restaurantList = restaurantList;
}
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder viewHolder, int position) {
if(context != null)
holder.data.setBackgroundResource(context.getResources().getDrawable(R.drawable.poster_infinity_war));
}
...
}
This will help you prevent OutOfMemoryException in future

Getting LARGE nested Json from NYT API

I'm trying to use the New york times api to show the headline and an image in a listview on android. I'm already getting the data for headline and date and outputting to log cat. The real problem is: whenever I put the extra field to get the mulimedia (images url) the "GC_FOR_ALLOC freed 1902K (64), 22% free 11931K/15156K" is shown
I've seen that the api always sends fixed number of 10 nyt articles, but each of the 10 has a multiple multimedia urls and json with arrays nested and the app freezes. I'll learn to put the data on listview on my own, my real question is, whats the best approach to fix the crash, I only want 1 url image per article.
//THE RETURNED JSON WITH ONLY "MULTIMEDIA" FIELD QUERY.
{
"status": "OK",
"copyright": "Copyright (c) 2018 The New York Times Company. All Rights
Reserved.",
"response": {
"docs": [
{
"multimedia": [
{
"rank": 0,
"subtype": "xlarge",
"caption": null,
"credit": null,
"type": "image",
"url": "images/2018/09/07/opinion/07Parcak/merlin_143215881_20cecc31-7c8d-4b8f-8541-773170c1822c-articleLarge.jpg",
"height": 400,
//MORE CODE HERE.. THEN NEXT ARRAY BELOW
{
"multimedia": [
{
"rank": 0,
"subtype": "xlarge",
"caption": null,
"credit": null,
"type": "image",
"url": "images/2018/09/03/world/03xp-brazil-promo/03xp-brazil-promo-articleLarge.jpg",
"height": 400,
"width": 600,
"legacy": {
"xlarge": "images/2018/09/03/world/03xp-brazil-promo/03xp-brazil-promo-articleLarge.jpg",
"xlargewidth": 600,
"xlargeheight": 400
},
"subType": "xlarge",
"crop_name": "articleLarge"
},
// Goes on forever.

What do you use to get the data, what kind of REST client are you using?
For example if you are parsing the response by yourself you can put some logic like
JSONObject obj = new JSONObject(" .... ");
JSONArray arr = obj.getJSONArray("multimedia");
JSONObject firstMultimedia = null;
if (arr.length() > 0){
firstMultimedia = arr.getJSONObject(0);
}

Retrofit JSON parsing issues in retrieving value from list ? How to solve?

I have A NESTED JSON to parse, for instance ;
[
{
"ID": {
"Tag": "string",
"TypeCode": 5,
"Value": "68613",
"IsBinaryUnique": true
},
"NATIVE_DATE": {
"Tag": "string",
"TypeCode": 5,
"Value": "2015/02/22",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_DATE": {
"Tag": "string",
"TypeCode": 5,
"Value": "February 22, 2015",
"IsBinaryUnique": true
},
"EXPIRY": {
"Tag": "string",
"TypeCode": 5,
"Value": "",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_DESCRIPTION": {
"Tag": "string",
"TypeCode": 5,
"Value": "",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_TITLE": {
"Tag": "string",
"TypeCode": 5,
"Value": "Emirates Motor Company unveils all-new Mercedes-Benz 2015 C-Class",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_IMAGE": {
"Tag": "string",
"TypeCode": 5,
"Value": "HTTP://94.56.199.34/EMC/EMCPortal/DesktopModules/Farabi.ICatalog/CatalogImages/488/C-2048_sd-eng.jpg",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_IMAGE_THUMBNAIL": {
"Tag": "string",
"TypeCode": 5,
"Value": "http://94.56.199.34/EMC/IPDP/thumbnail.ashx?File=/DesktopModules/Farabi.ICatalog/CatalogImages/488/C-2048_sd-eng.jpg",
"IsBinaryUnique": true
},
"ANNOUNCEMENT_HTML": {
"Tag": "string",
"TypeCode": 5,
"Value": "<!--NEWS-->\r\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n<head>\r\n <meta name=\"viewport\" content=\"width=device-width\" />\r\n <title>News & Promotions</title>\r\n <style type=\"text/css\">\r\n H1\r\n {\r\n text-align: left;\r\n color:Black;\r\n font-size:22px;\r\n font-weight: bold;\r\n font-family:Arial;\r\n }\r\n Body\r\n {\r\n background-color: transparent\";\r\n font-family:Arial;\r\n }\r\n .Header\r\n {\r\n -webkit-border-top-left-radius: 10px;\r\n -webkit-border-bottom-left-radius: 10px;\r\n -moz-border-radius-topleft: 10px;\r\n -moz-border-radius-bottomleft: 10px;\r\n border-top-left-radius: 10px;\r\n border-bottom-left-radius: 10px;\r\n background-color: #0e100f\";\r\n margin-top: 10px;\r\n font-weight: bold;\r\n border: 5 none transperant;\r\n font-family:Arial;\r\n }\r\n .SubTitle\r\n {\r\n color: black;\r\n font-weight: bold;\r\n font-size:16px;\r\n font-family:Arial;\r\n }\r\n \r\n .ContentText\r\n {\r\n color: black;\r\n font-size:16px;\r\n font-family:Arial;\r\n }\r\n \r\n .Content\r\n {\r\n margin-left: 5px;\r\n }\r\n </style>\r\n</head>\r\n<body leftmargin=\"0\" topmargin=\"0\">\r\n <table border=\"0\" cellpadding=\"5\" cellspacing=\"5\" >\r\n <tr>\r\n <td>\r\n <h1>\r\n Emirates Motor Company unveils all-new Mercedes-Benz 2015 C-Class\r\n </h1>\r\n </td>\r\n </tr>\r\n <tr class=\"SubTitle\">\r\n <td align=\"right\">\r\n February 22, 2015\r\n </td>\r\n </tr>\r\n <tr class=\"SubTitle\">\r\n <td align=\"right\">\r\n Valid Till &nbsp $Expired_Date\r\n </td>\r\n </tr>\r\n <tr>\r\n <td>\r\n <img alt=\"\" src=\"http://94.56.199.34/EMC/EMCPortal/DesktopModules/Farabi.ICatalog/CatalogImages/488/C-2048_sd-eng.jpg\" style=\"width: 100%; float: right\" hspace=\"0\" />\r\n </td>\r\n </tr>\r\n <tr>\r\n <td> \r\n <div class=\"Content\" valign=\"top\">\r\n <table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"100%\">\r\n <tr>\r\n <td class=\"ContentText\" align=\"left\">\r\n <p><span>Emirates Motor Company (EMC), General Distributors of Mercedes-Benz in the Emirate of Abu Dhabi and the flagship company of Al Fahim Group, launched the all-new Mercedes-Benz 2015 C-Class in a gala iftar and a superb unveiling of the fabulous new innovative car on Saturday, 5 July at their close-to-heart Airport Road Showroom in Abu Dhabi.</span></p>\r\n<p><span>In the presence of newly appointed CEO Automotive of Al Fahim Group, Mr. Frank Bernthaler, the celebrative evening continued with a press conference where EMC hosts Mr. Kamal Rafih, General Manager, Mr. Jordan Duckett, General Sales Manager, and Mr. Rabih Eid, Operations Manager, were head-table spokespersons.</span></p>\r\n<p><span>\"We are delighted to be revealing the admirable all-new Mercedes-Benz 2015 C-Class during a blessed, festive month and announce the great achievements we've accomplished so far this year,\" praised Mr. Rafih in his speech to the media. \"As we conclude the first half of the year, we also celebrate a well-earned increase in our sales performance of 42% compared to the same period last year,\" he added.</span></p>\r\n<p><span>Among the most popular models in 2014 which witnessed an exponential rise were the legendary Mercedes-Benz S-Class by an impressive 347%, the sporty A-Class by 156%, the luxurious E-Class by 46%, and the entire sports utility vehicle (SUV) range by 22%, which includes the G-Class, GL-Class, GLK Class and the M-Class.</span></p>\r\n<p><span>During the memorable occasion, media representatives and guests were also invited to explore the latest innovation by Mercedes-Benz and register for the driving experience. The all-new C-Class sets new standards in the premium medium-size category in terms of striking appearance, cutting-edge technology, spacious comfort and refined sportiness. A host of new assistance systems offers safety of the highest standard, while a new optional air-sprung suspension provides for exemplary ride and driving comfort as well as nimble and agile handling.</span></p>\r\n<p><span>Thanks to intelligent and innovative lightweight construction, the aluminum hybrid body is around 70 kilograms lighter than a conventional steel body. Compared with the successful predecessor, the aluminum content has increased from less than 10% to almost 50%. As a result, the vehicle's overall weight is reduced by up to 100 kilograms. Furthermore, with an 80-millimeter increase in the wheelbase compared with the previous model, the vehicle is 95 millimeters longer and 40 millimeters wider. The result is a more spacious interior.</span></p>\r\n<p><strong><span>High-class interior with fine details</span></strong><span><br />\r\nThe innovative touchpad developed by Mercedes-Benz in the hand-rest marks a further evolutionary step. As on a smartphone, this provides for simple and intuitive operation of all the head-unit functions using finger gestures. The touchpad also permits letters, numbers and special characters to be entered in handwriting - in any language supported by Audio 20. One of the main highlights of the innovative touchpad is that Arabic letters, numbers and even special characters are supported, and can be entered into the handwriting recognition function.</span></p>\r\n<p><strong><span>Mercedes-Benz Intelligent Drive: the intelligent car</span></strong><span><br />\r\nThe new C-Class incorporates almost all of the new assistance systems with a host of enhanced functions which celebrated their world premiere in the S-Class and E-Class only some months ago. The assistance systems enhance both comfort and safety. Mercedes-Benz calls this Intelligent Drive.</span></p>\r\n<p><span>The new C-Class offers numerous innovative safety and assistance systems. It is equipped as standard with ATTENTION ASSIST, which can warn the driver of inattentiveness and fatigue. In addition to Adaptive Brake Assist, which offers protection from collisions from speeds as low as 7 km/h, standard-fit COLLISION PREVENTION ASSIST PLUS also features an additional function: when the risk of collision persists and the driver fails to respond, the system is able to carry out autonomous braking at speeds of up to 200 km/h, thereby reducing the severity of collisions with slower or stopping vehicles. The system also brakes in response to stationary vehicles at a speed of up to 50 km/h, and is able to prevent rear-end collisions at up to 40 km/h.</span></p>\r\n<p><strong><span>Other safety features include:</span></strong> <span><br />\r\n-DISTRONIC PLUS with Steering Assist and integrated Stop&Go Pilot\r\n<br />\r\n-BAS PLUS Brake Assist and PRE-SAFE® Brake\r\n<br />\r\n-Enhanced Active Lane Keeping Assist\r\n<br />\r\n-Active Parking Assist\r\n<br />\r\n-Traffic Sign Assist\r\n<br />\r\n-Adaptive Highbeam Assist Plus</span></p>\r\n </td>\r\n </tr>\r\n </table>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n</body>\r\n</html>\r\n",
"IsBinaryUnique": true
}
},
{
"ID": {
"Tag": "string",
"TypeCode": 5,
"Value": "66055",
"IsBinaryUnique": true
}, etc....}]
I need to get the announcement title values, in order to do this I have created a model class for Announcement Title.
public class AnnouncementTitle {
#SerializedName("Tag")
private String tag;
#SerializedName("TypeCode")
private String typecode;
#SerializedName("Value")
private String value;
#SerializedName("IsBinaryUnique")
private boolean isbinary;
public AnnouncementTitle(String tag, String typecode, String value, boolean isbinary) {
this.tag = tag;
this.typecode = typecode;
this.value = value;
this.isbinary = isbinary;
}
public String getTag() {
return tag;
}
public void setTag(String tag) {
this.tag = tag;
}
public String getTypecode() {
return typecode;
}
public void setTypecode(String typecode) {
this.typecode = typecode;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public boolean isIsbinary() {
return isbinary;
}
public void setIsbinary(boolean isbinary) {
this.isbinary = isbinary;
}
}
and my API class is like,
public interface Api {
String BASE_URL ="base url";
#GET("url to get values from")
Call<ArrayList<AnnouncementTitle>> getData();}
I have implemented the retrofit call in MainActivity.java
public void getData() {
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(Api.BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
Api api = retrofit.create(Api.class);
Call<ArrayList<AnnouncementTitle>> call = api.getData();
call.enqueue(new Callback<ArrayList<AnnouncementTitle>>() {
#Override
public void onResponse(Call<ArrayList<AnnouncementTitle>> call, Response<ArrayList<AnnouncementTitle>> response) {
ArrayList<AnnouncementTitle> response_array = response.body();
Log.e("Response "," "+ response_array);
Log.e("Response "," "+ response_array.size());
Log.e("Response ","Value "+ response_array.get(0).getValue());
for (int i = 0;i<response_array.size();i++){
AnnouncementTitle announcementTitle= response_array.get(i);
String a = announcementTitle.getTag();
String b = announcementTitle.getValue();
String c = announcementTitle.getTypecode();
//Log.e("Response ","Value "+ b);
// Log.e("Response ","Value "+ c);
}
}
#Override
public void onFailure(Call<ArrayList<AnnouncementTitle>> call, Throwable t) {
Log.e("Failed "," ");
}
});
}}
My problem is I get the response as array list correctly, but the values inside ArrayList are null for instance from the above code the string values a,b,c, all of them returning value as null.Can anyone help to find and resolve this problem?.

First: JSON you are showing is invalid. Apart from invalid braces placement if you declare
#SerializedName("TypeCode")
private String typecode;
you will have
"TypeCode": "5"
instead of
"TypeCode": 5
in JSON. The correct JSON representing your an ArrayList<AnnouncementTitle> is:
[
{"ID": {
"Tag": "string",
"TypeCode": "5",
"Value": "68613",
"IsBinaryUnique": true}
},
{"NATIVE_DATE": {
"Tag": "string",
"TypeCode": "5",
"Value": "2015/02/22",
"IsBinaryUnique": true}
},
{"ANNOUNCEMENT_TITLE": {
"Tag": "string",
"TypeCode": "5",
"Value": "Title of announcement",
"IsBinaryUnique": true}
}
]
Second: Your request and response have the same structure - ArrayList<AnnouncementTitle>. You are sending this list and getiing it back as an server answer. Is it really the thing you want to do?
Third: If you really want ArrayList<AnnouncementTitle> as an server answer why do you parse it by hand with
for (int i = 0;i<response_array.size();i++){
...
}
? It would be better to force Retrofit do that for you with:
call.enqueue(new Callback<ArrayList<AnnouncementTitle>>() {
#Override
public void onResponse(Call<ArrayList<AnnouncementTitle>> call, ArrayList<AnnouncementTitle> list) {
ArrayList<AnnouncementTitle> response_list = list;
}

Get JSON object from list like this
JSONObject obj = responseArray.get(i);
JSONObject ID = obj.getJSonObject("ID");
Variables in your model class should be like this (I think you forgot to set
TypeCode to declare Integer)
#SerializedName("Tag")
private String tag;
#SerializedName("TypeCode")
private int typecode;
#SerializedName("Value")
private String value;
#SerializedName("IsBinaryUnique")
private boolean isbinary;
Pass the data in to model class like this in for loop
AnnouncementTitle model = new AnnouncementTitle(
ID.getString("TAG"),
ID.getInt("TypeCode"),
ID.getString("Value"),
ID.getBoolean("IsBinaryUnique")
);

copy your all json response and change it to pojo class from the link
https://www.jsonutils.com/
and make the get set method in class
your interface will become like that
public interface Api {
#GET("url to get values from")
Call<PojoClassName> getData();
}
retrofit class look like that
Api api = retrofit.create(Api.class);
Call<PojoClassName> call = api.getData();
call.enqueue(new Callback<PojoClassName>() {
#Override
public void onResponse(Call<PojoClassName> call, Response<PojoClassName> response) {
Log.e("Response "," "+response.body().toString);
Log.e("Response "," "+response.body().getID().getTag());
Log.e("Response "," "+response.body().getEXPIRY().getTag());
}
#Override
public void onFailure(Call<PojoClassName> call, Throwable t) {
Log.e("Failed ",t.getMessage());
}
});

Parse Nested JSON data in Android

I am trying to parse JSON data which looks like this in android;
{
"data": [{
"http_code": 200,
"message": "success",
"created_at": "2016/10/12",
"categories": [{
"cat_id": 1,
"cat_name": "Business and Commerce",
"subcategories":[{
"subcat_id": 1,
"subcat_name": "Intellectual Property",
"articles":[{
"article_id": 1,
"article_heading": "What is intellectual?",
"article_url": "http://example.com/1"
},{
"article_id": 2,
"article_heading": "Types of intellectual Properties",
"article_url": "http://example.com/2"
}]
}, {
"subcat_id": 2,
"subcat_name": "Business Licensing",
"articles":[{
"article_id": 1,
"article_heading": "What is a license?",
"article_url": "http://example.com/1"
},{
"article_id": 2,
"article_heading": "Types of Business Licenses",
"article_url": "http://example.com/2"
}]
}]
}, {
"cat_id": 2,
"cat_name": "Family Law",
"subcategories":[{
"subcat_id": 3,
"subcat_name": "Domestic Violence",
"articles":[{
"article_id": 1,
"article_heading": "What is domestic violene?",
"article_url": "http://example.com/1"
},{
"article_id": 2,
"article_heading": "Types of domestic violence",
"article_url": "http://example.com/2"
}]
}, {
"subcat_id": 4,
"subcat_name": "Marriage",
"articles":[{
"article_id": 1,
"article_heading": "What is a marriage?",
"article_url": "http://example.com/1"
},{
"article_id": 2,
"article_heading": "Types of marriages",
"article_url": "http://example.com/2"
}]
}]
}]
}]
}
I am supposed to see data for a specific node when I select it via a listview list item click and so on....
So far I have managed to parse all the categories and display them in a listview, but I want to display subcategories for a category I select on the listview.

Set an onItemClickListener on your listview and use the position of the selected item to return the relevant subcategories?
For example, perhaps something along the lines of:
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Switch(position) {
case 0:
//get first subcategories array values
break;
case 1:
//get second subcategories array values
break;
....
}
}

Use ExpandableListView, example given on this link.
For json parsing use Google gson, it will make your work easy and efficient.

It seems similar to How to parse this nested JSON array in android
But you can use this lib https://github.com/FasterXML/jackson
to make the work easy and faster using Objects.
It is a small tutorial: JacksonInFiveMinutes
Specially: Full Data Binding (POJO) Example. And JacksonDataBinding

Thanks everyone for your help. I finally managed to solve the issue;
Here is how I did it;
JSONObject jsonObj = new JSONObject(jsonStr);
JSONObject subcategories = jsonObj.getJSONObject("data").getJSONArray("categories").getJSONObject((int)getItemId(position));
Log.e("TAG","Subcategories: " + subcategories);
I don't know if that is the correct way, but it worked in my case.

How to fetch large images from discogs api?

Is it possible to get higher quality images from discogs api? Right now I can only get a thumbnail image of size 150x150. Is there any way for developers to get a better quality image? The JSON only has link for thumnail images.
So if this is my request
https://api.discogs.com/database/search?page=1&per_page=1&key=my_key&secret=my_secret&q=Waka%20Waka
This is the response that I get
{
"pagination":{
"per_page":1,
"items":1731,
"page":1,
"urls":{
"last":"https://api.discogs.com/database/search?q=Waka+Waka&per_page=1&secret=my_secret&page=1000&key=my_key",
"next":"https://api.discogs.com/database/search?q=Waka+Waka&per_page=1&secret=my_secret&page=2&key=my_key"
},
"pages":1000
},
"results":[
{
"style":[
"Alternative Rock",
"Jazz-Rock",
"Fusion"
],
"thumb":"https://api-img.discogs.com/YokvweulGO7tRuNoSv3b1F4UntQ=/fit-in/150x150/filters:strip_icc():format(jpeg):mode_rgb():quality(40)/discogs-images/R-1378139-1466530254-6813.jpeg.jpg",
"format":[
"Vinyl",
"LP",
"Album"
],
"country":"US",
"barcode":[
"(31,456) RE I",
"(31,457) RE I",
"MS-2094 31456-1",
"MS-2094 31457-1",
"S1\u00b7MS 2094A 31456-Re1-T2 ",
"25 MS 20941 31457 Re1\u00b7T2",
"ASCAP"
],
"uri":"/Frank-Zappa-Waka-Jawaka-Hot-Rats/master/35744",
"community":{
"have":3089,
"want":1992
},
"label":[
"Bizarre Records",
"Reprise Records",
"Warner Bros. Records Inc.",
"Warner Bros. - Seven Arts Records, Inc.",
"Warner Bros. Records Inc.",
"Warner Bros. Records Inc.",
"Munchkin Music",
"Paramount Studios"
],
"catno":"MS 2094",
"year":"1972",
"genre":[
"Rock"
],
"title":"Frank Zappa - Waka / Jawaka \u2022 Hot Rats",
"resource_url":"https://api.discogs.com/masters/35744",
"type":"master",
"id":35744
}
]
}
I want to have larger images, how can I do that? Is that even possible? Thanks !!

When you search for releases you get an id that you can use to get more release info.
Make call to https://api.discogs.com/releases/{id}?key={your_key}&secret={your_secret}
Response usually has some image urls that you can download.