I have to develop an ecommerce app and I have a question regarding lists. I'm getting a JSON with some product data from an API and I'm trying to grab each object from that JSON, put it in a list and show each product with its data in an Activity. But I've tried everything and still do not list anything, the screen goes blank
JSON that is returned
[
{
"id": 7,
"name": "Repelente Premium Bite Stop",
"price": "35.5000",
"description": "O repelente Premium Bite Stop é indicado para cães, gatos,
cavalos, ferrets e roedores. Protege objetos e móveis que os
animais possam lamber, mastigar ou morder. Pode ser utilizado
sobre a pele para desencorajar automutilação e para proteção de
talas, feridas pós-cirúrgicas e curativos. Não é tóxico.",
"discountPromotion": "0.00",
"activeProduct": 1,
"minimumStockQuantity": 30,
"image": "FFD8FFE000104A46494600010101006000600000FFE100224578696600004D4D002A000000...",
"categoryId": 3
},
{
"id": 6,
"name": "Dry Shampoo Banho a Seco",
"price": "25.0000",
"description": "Indicado para:\r\n\r\nCachorro, todas as raças;\r\nA partir de
2 meses de idade;\r\nA embalagem é de 150ml;\r\nPet Clean /
Linha Shampoo Banho Seco;\r\n\r\nBenefícios:\r\n\r\nEconomiza
água e deixa seu pet limpo e cheiroso;\r\nFácil e prático de
aplicar;\r\nIndicado para todos os tipos de pelo;\r\nNão
precisa enxágue;\r\nAroma de Morango e Limonada;",
"discountPromotion": "3.00",
"activeProduct": 1,
"minimumStockQuantity": 10,
"image": ""FFD8FFE000104A46494600010101006000600000FFDB0043...",
"categoryId": 5
}
]
MainActivity Code
import java.text.NumberFormat;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.support.design.widget.NavigationView;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Base64;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private ListView list_products;
private ImageView product_picture;
private TextView product_name;
private TextView product_price;
private TextView product_description;
private NavigationView navigationView;
private DrawerLayout drawerLayout;
private ActionBarDrawerToggle actionBarDrawerToggle;
List<Product> products = new ArrayList<Product>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
NetWorkCall myCall = new NetWorkCall();
myCall.execute("http://kanino-pi4.azurewebsites.net/Kanino/api/produtos");
list_products = (ListView) findViewById(R.id.list_products);
product_name = (TextView) findViewById(R.id.product_name);
product_price = (TextView) findViewById(R.id.product_price);
product_description = (TextView) findViewById(R.id.product_description);
ArrayAdapter<Product> adapter = new ArrayAdapter<Product>(this, android.R.layout.simple_list_item_1, products);
list_products.setAdapter(adapter);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
//--------------NAVIGATION VIEW---------------------
navigationView = (NavigationView) findViewById(R.id.navigation_view);
navigationView.setNavigationItemSelectedListener(
new NavigationView.OnNavigationItemSelectedListener(){
public boolean onNavigationItemSelected(MenuItem menuItem){
if(menuItem.isChecked()){
menuItem.setChecked(false);
}else{
menuItem.setChecked(true);
}
drawerLayout.closeDrawers();
if(menuItem.getItemId() == R.id.action_product){
ProductFragment fragment = new ProductFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.frag_container, fragment).commit();
return true;
}
if(menuItem.getItemId() == R.id.action_login){
LoginFragment fragment = new LoginFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.frag_container, fragment).commit();
return true;
}
if(menuItem.getItemId() == R.id.action_register){
RegisterFragment fragment = new RegisterFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.frag_container, fragment).commit();
return true;
}
if(menuItem.getItemId() == R.id.action_register){
RegisterFragment fragment = new RegisterFragment();
getSupportFragmentManager().beginTransaction().replace(R.id.frag_container, fragment).commit();
return true;
}
return false;
}
}
);
drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.openDrawer, R.string.closeDrawer){};
drawerLayout.setDrawerListener(actionBarDrawerToggle);
actionBarDrawerToggle.syncState();
//--------------------------------------------------------
}
public boolean onOptionsItemSelected(MenuItem item){
if(actionBarDrawerToggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
public class NetWorkCall extends AsyncTask<String, Void, String>{
@Override
protected String doInBackground(String... params) {
try{
HttpURLConnection urlConnection = (HttpURLConnection) new URL(params[0]).openConnection();
urlConnection.setConnectTimeout(4000);
InputStream in = urlConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
StringBuilder resultado = new StringBuilder();
String linha = bufferedReader.readLine();
while(linha != null){
resultado.append(linha);
linha = bufferedReader.readLine();
}
String respostaCompleta = resultado.toString();
return respostaCompleta;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String result){
super.onPostExecute(result);
try{
JSONArray json = new JSONArray(result);
for(int i = 0; i < json.length(); i++) {
JSONObject j = json.getJSONObject(0);
Product product = new Product(j.getInt("id"),
j.getString("name"),
j.getString("price"),
j.getString("description"),
j.getString("discountPromotion"),
j.getInt("activeProduct"),
j.getInt("minimumStockQuantity"),
j.getString("image"));
addAtTheList(product);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void addAtTheList(Product product){
products.add(product);
}
}
}