JsonActivity.java

import android.os.AsyncTask;

import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

public class JsonActivity extends AsyncTask<String, Void, JSONObject> {

    @Override
    protected JSONObject doInBackground(String... params) {
        URL url;
        URLConnection connection;
        BufferedReader reader = null;
        StringBuffer buffer;
        String line;

        try {
            url = new URL(params[0]);
            connection = url.openConnection();
            reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            buffer = new StringBuffer();

            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }

            return new JSONObject(buffer.toString());
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    @Override
    protected void onPostExecute(JSONObject json) {
        if (json != null) {
            // Get JSON here
        }
    }

}