Okhttp With ListView Json Example in Android

Add Library

compile 'com.squareup.okhttp3:okhttp:3.8.1'
compile 'com.google.code.gson:gson:2.6.2'

OkhttpListViewActivity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.bhaumik.networkingtask.OKhttpListViewActivity">


    <ListView
        android:id="@+id/okhttp_listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

okhttp_list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_marginTop="10dp"
    app:cardBackgroundColor="@android:color/holo_blue_light">
        <TextView
            android:id="@+id/text_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center_horizontal"
            android:layout_marginTop="20dp"
            android:textColor="@android:color/background_light"
            android:textSize="20dp"
            android:maxLength="5"
            android:text="Hello World"/>

</android.support.v7.widget.CardView>

OkhttpListViewActivity.java

package com.example.bhaumik.networkingtask;

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;

import com.example.bhaumik.networkingtask.adapter.OkhttpListAdapter;
import com.example.bhaumik.networkingtask.pojo.Image;
import com.example.bhaumik.networkingtask.pojo.Network;
import com.google.gson.Gson;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class OKhttpListViewActivity extends AppCompatActivity {

    OkhttpListAdapter adapter;
    List<Image> list = new ArrayList<>();
    ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_okhttp_list_view);

        listView = (ListView) findViewById(R.id.okhttp_listview);

        adapter = new OkhttpListAdapter(list,OKhttpListViewActivity.this);
        listView.setAdapter(adapter);

        new MyTask().execute();
    }

    public class MyTask extends AsyncTask<Void,Void,String>{

        String url = "http://bing.com/HPImageArchive.aspx?format=js&idx=0&n=20&mkt=en-US";

        @Override
        protected String doInBackground(Void... voids) {

            try {

                OkHttpClient client = new OkHttpClient();
                Request request = new Request.Builder().url(url).build();
                Response response = client.newCall(request).execute();

                Gson gson = new Gson();

                Network network = gson.fromJson(response.body().string(),Network.class);
                List<Image> list_data = network.getImages();

                for (Image image : list_data){
                        list.add(image);
                }

                return "Size -> " + list.size();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String aVoid) {
            super.onPostExecute(aVoid);
            adapter.notifyDataSetChanged();
        }
    }
}

OkhttpListAdapter.java

package com.example.bhaumik.networkingtask.adapter;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.example.bhaumik.networkingtask.R;
import com.example.bhaumik.networkingtask.pojo.Image;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by Bhaumik on 9/3/2017.
 */

public class OkhttpListAdapter extends BaseAdapter{

    List<Image> list = new ArrayList<>();
    Context context;

    public OkhttpListAdapter(List<Image> list, Context context) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int i) {
        return list.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        ViewHolder viewHolder;

        if (convertView == null){

            View view = LayoutInflater.from(context).inflate(R.layout.okhttp_item_list,parent,false);

            viewHolder = new ViewHolder(view);
            view.setTag(viewHolder);
        }else{
            viewHolder = (ViewHolder) convertView.getTag();
        }

        Image image = list.get(position);

        viewHolder.textView.setText(image.getCopyright());

        return viewHolder.itemView;
    }

    public static class ViewHolder{

        TextView textView;
        View itemView;

        public ViewHolder(View itemView) {
            this.itemView = itemView;
            textView = itemView.findViewById(R.id.text_view);
        }

    }
}