How to load data (json) into recycling using volleyball

Question

I implemented recyclerview in my application, and now I need to get data from the server, and I just found out that volleyball is the best way to get data. I searched the Internet, but I can’t find a suitable tutorial for it.

This is how I initialized recyclerview in my code. (which has a set of hardcoded data)

mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview); LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this); linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL); mRecyclerView.setLayoutManager(linearLayoutManager); mAdapter = new CardAdapter(); mRecyclerView.setAdapter(mAdapter); 

here is the adapter code.

 public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder> { ArrayList<BusRouteNameDetails> mItems; public int TAG=0; public CardAdapter() { super(); mItems = new ArrayList<>(); BusRouteNameDetails routename = new BusRouteNameDetails(); routename.setName("xyz"); routename.setNumber("X4"); mItems.add(routename); routename = new BusRouteNameDetails(); routename.setName("xyz"); routename.setNumber("X4"); mItems.add(routename); routename = new BusRouteNameDetails(); routename.setName("xyz"); routename.setNumber("X4"); mItems.add(routename); routename = new BusRouteNameDetails(); routename.setName("xyz"); routename.setNumber("X4"); mItems.add(routename); routename = new BusRouteNameDetails(); routename.setName("xyz"); routename.setNumber("X4"); mItems.add(routename); } @Override public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { View v = LayoutInflater.from(viewGroup.getContext()) .inflate(R.layout.busroutename_list, viewGroup, false); ViewHolder viewHolder = new ViewHolder(v); return viewHolder; } @Override public void onBindViewHolder(ViewHolder viewHolder, int i) { BusRouteNameDetails routename = mItems.get(i); viewHolder.tvName.setText(routename.getName()); viewHolder.tvRoutename.setText(routename.getNumber()); Log.e("TAG","i value="+ i); if(i==mItems.size()-1) viewHolder.seperator.setVisibility(View.INVISIBLE); } @Override public int getItemCount() { Log.e("TAG","item size"+ mItems.size()); return mItems.size(); } class ViewHolder extends RecyclerView.ViewHolder{ public TextView tvName; public TextView tvRoutename; public View seperator; public ViewHolder(View itemView) { super(itemView); tvName = (TextView)itemView.findViewById(R.id.RouteName1); tvRoutename = (TextView)itemView.findViewById(R.id.Route_src_dest); seperator=(View)itemView.findViewById(R.id.seperator); } } } 

And here getters and setters

 public class BusRouteNameDetails { private String mName; private String mNumber; public String getName() { return mName; } public void setName(String name) { this.mName = name; } public String getNumber() { return mNumber; } public void setNumber(String Number) { this.mNumber = Number; } } 

Answer 1

You can try as my following solution:

Suppose the server response is as the following JSON:

 [ { "name": "Person 1", "age": 30 }, { "name": "Person 2", "age": 20 }, { "name": "Person 3", "age": 40 } ] 

In your Android project:

 public class Person { String name; Integer age; Person() { } } public class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder> { List<Person> persons; RVAdapter(List<Person> persons) { this.persons = persons; } @Override public PersonViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false); PersonViewHolder pvh = new PersonViewHolder(v); return pvh; } @Override public void onBindViewHolder(PersonViewHolder holder, int position) { holder.personName.setText(persons.get(position).name); holder.personAge.setText(String.valueOf(persons.get(position).age)); } @Override public int getItemCount() { if (persons != null) { return persons.size(); } return 0; } @Override public void onAttachedToRecyclerView(RecyclerView recyclerView) { super.onAttachedToRecyclerView(recyclerView); } public static class PersonViewHolder extends RecyclerView.ViewHolder { CardView cv; TextView personName; TextView personAge; PersonViewHolder(View itemView) { super(itemView); cv = (CardView) itemView.findViewById(R.id.cv); personName = (TextView) itemView.findViewById(R.id.person_name); personAge = (TextView) itemView.findViewById(R.id.person_age); } } } 

Then in your activity:

  ... RecyclerView rv = (RecyclerView)findViewById(R.id.rv); rv.setHasFixedSize(true); LinearLayoutManager llm = new LinearLayoutManager(mContext); rv.setLayoutManager(llm); final RVAdapter rvAdapter = new RVAdapter(personList); rv.setAdapter(rvAdapter); RequestQueue requestQueue = Volley.newRequestQueue(mContext); String url = "http://192.16.1.100/api/persons"; JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new Response.Listener<JSONArray>() { @Override public void onResponse(JSONArray response) { try { if (response.length() > 0) { personList.clear(); for (int i = 0; i < response.length(); i++) { JSONObject jsonObject = response.getJSONObject(i); Person person = new Person(); if (!jsonObject.isNull("name")) { person.name = jsonObject.getString("name"); } if (!jsonObject.isNull("age")) { person.age = jsonObject.getInt("age"); } personList.add(i, person); } rvAdapter.notifyDataSetChanged(); } } catch (JSONException e) { e.printStackTrace(); } } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { // do something } }); requestQueue.add(jsonArrayRequest); ... 

Here is the result

Hope this helps!