I'm designing an Android app that downloads information from a website and prints a list on-screen with that information in the form of an Array List.
However, the ArrayList I use doesn't load correctly and my screen becomes blank.
Activity code:
Tenda.java
public class Tenda extends Activity implements OnItemClickListener, LocationListener {
ProgressDialog lDialog;
String json_string;
SuperAdapter adapter_super;
int user_id;
private LocationManager locationManager;
public String provider;
private String lattitude , longitude;
/*************************************************/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tenda);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
init_conf();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.tenda, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.menu_update:
updateList();
return true;
case R.id.menu_search:
alert_search();
return true;
case R.id.menu_cancel:
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long arg3) {
TextView stock = (TextView) view.findViewById(R.id.list_product_stock);
int num_stock = Integer.parseInt(stock.getText().toString()) ;
if(num_stock!=0){
ArrayList<Super> productes=adapter_super.getItems_producte();
Super current_product= productes.get(position);
alert_buy(num_stock,current_product);
}
else
{
Toast.makeText(this, "OUT OF STOCK", Toast.LENGTH_LONG).show();
}
}
private void init_conf(){
Bundle extras = getIntent().getExtras();
user_id = extras.getInt("user_id");
Toast.makeText(this, "user id"+Integer.toString(user_id), Toast.LENGTH_LONG).show();
ListView lsv_producto = (ListView)findViewById(R.id.list_productes);
adapter_super = new SuperAdapter(Tenda.this,null);
lsv_producto.setAdapter(adapter_super);
lsv_producto.setOnItemClickListener(this);
updateList();
}
private void updateList(){
loading();
String url = "http://www.v2msoft.com/clientes/lasalle/curs-android/products.php?user_id="+user_id;
boolean is_con=is_connected();
if(is_con){
Log.i("Connection", "true");
AsyncTask(url);
Toast.makeText(this, "connected internet", Toast.LENGTH_LONG).show();
}
else{
json_string=storeRead();
refreshListByJson(json_string);
Toast.makeText(this, "not connected internet", Toast.LENGTH_LONG).show();
}
}
private void search(String text){
loading();
String url="http://www.v2msoft.com/clientes/lasalle/curs-android/search.php?user_id="+user_id+"&q="+text;
boolean is_con=is_connected();
if(is_con){
Log.i("search URL", url);
Toast.makeText(this, url, Toast.LENGTH_LONG).show();
searchAsyncTask(url);
}
else{
Toast.makeText(this, "NO CONNECTION", Toast.LENGTH_LONG).show();
}
}
private void buy(Super producte, int value){
int product_id= producte.getId();
String url="http://www.v2msoft.com/clientes/lasalle/curs-android/buy.php?user_id="+user_id+
"&product_id="+product_id+
"&items="+value+
"&lat="+1+
"&long="+1;
Toast.makeText(this, url, Toast.LENGTH_LONG).show();
}
private void AsyncTask(String url){
LongAsyncTask task = new LongAsyncTask();
task.execute(url);
}
private void searchAsyncTask(String url){
SearchAsyncTask task = new SearchAsyncTask();
task.execute(url);
}
public void alert_search(){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Title");
final EditText input = new EditText(this);
input.setInputType(InputType.TYPE_CLASS_TEXT);
builder.setView(input);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String m_Text = input.getText().toString();
Toast.makeText(getApplicationContext(), m_Text, Toast.LENGTH_LONG).show();
search(m_Text);
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
builder.show();
}
public void alert_buy(int max_value,final Super producte){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("BUY");
final NumberPicker number= new NumberPicker(this);
number.setMaxValue(max_value);
number.setMinValue(0);
builder.setView(number);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
int value= number.getValue();
Toast.makeText(getApplicationContext(), value+"", Toast.LENGTH_LONG).show();
buy(producte,value);
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
builder.show();
}
/*************************ASYNC TASK************************/
public class LongAsyncTask extends AsyncTask<String,String,String>{
@Override
protected String doInBackground(String... url) {
String url_result= conect(url[0]);
Log.i("DO IN BACKGROUND", url_result);
return url_result;
}
protected void onPostExecute(String url_result) {
Log.i("On Post EXECUTE", url_result);
json_string= url_result;
storeWrite(json_string);
refreshListByJson(json_string);//line 257
}
}
public class SearchAsyncTask extends AsyncTask<String,String,String>{
@Override
protected String doInBackground(String... url) {
String url_result= conect(url[0]);
Log.i("Search result", url_result);
return url_result;
}
protected void onPostExecute(String url_result) {
Log.i("On Post EXECUTE SEARCH", url_result);
json_string= url_result;
Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
refreshListByJson(json_string);
}
}
public class BuyAsyncTask extends AsyncTask<String,String,String>{
@Override
protected String doInBackground(String... url) {
String url_result= conect(url[0]);
Log.i("buy result", url_result);
return url_result;
}
protected void onPostExecute(String url_result) {
Log.i("On Post EXECUTE SEARCH", url_result);
json_string= url_result;
Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
}
}
/*************************************************/
private void refreshListByJson(String json){//line 300
lDialog.dismiss();
Store store=Store.newStore(json);
if (store.getProductes() != null)
{
Log.i("store-nom", "" + store.getStore());//line 305
Log.i("store-producte", "" + store.getProductes().toString()); //line 306
adapter_super.setItems_producte(store.getProductes());
}
}
private void storeWrite(String data){
String FILENAME = "json_store";
FileOutputStream fos;
try {
fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(data.getBytes());
fos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.i("Write STORAGE", data);
}
private String storeRead(){
String FILENAME = "json_store";
FileInputStream fis;
StringBuilder fileContent = new StringBuilder();
try {
fis= openFileInput (FILENAME);
BufferedReader br= new BufferedReader(new InputStreamReader(fis));
String line;
while((line = br.readLine())!= null)
{
fileContent.append(line);
}
br.close();
fis.close();
Log.i("READ STORAGE", fileContent.toString());
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return fileContent.toString();
}
public String conect(String url_string){
HttpURLConnection con = null;
BufferedReader reader= null;
try{
URL url = new URL(url_string);
con = (HttpURLConnection)url.openConnection();
reader= new BufferedReader(new InputStreamReader(con.getInputStream()));
String line ="";
StringBuffer responseBuffer = new StringBuffer();
while((line=reader.readLine())!=null)
{
responseBuffer.append(line);
}
return responseBuffer.toString();
}
catch(Exception ex){
Log.e(getClass().getName(), ex.getMessage(),ex);
return null;
}
}
public boolean is_connected(){
ConnectivityManager conMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo i = conMgr.getActiveNetworkInfo();
if (i == null)
return false;
if (!i.isConnected())
return false;
if (!i.isAvailable())
return false;
return true;
}
private void loading(){
lDialog = new ProgressDialog(this);
lDialog.setMessage("Loading...");
lDialog.setCancelable(false);
lDialog.show();
}
/*** Location ***/
@Override
public void onLocationChanged(Location arg0) {
// TODO Auto-generated method stub
int lat = (int) (arg0.getLatitude());
int lng = (int) (arg0.getLongitude());
lattitude = "Lattitude: "+ lat ;
longitude = "Longitude: "+ lng;
}
@Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
////TODO Auto-generated method stub
}
}
Store.java
public class Store {
private String store;
private ArrayList<Super> productes;
public String getStore() {
return store;
}
public void setSuper(String store) {
this.store = store;
}
public ArrayList<Super> getProductes() {
return productes;
}
public void setProductes(ArrayList<Super> productes) {
this.productes = productes;
}
static Store newStore(String json_string){
Gson gson= new Gson();
Store store = gson.fromJson(json_string,Store.class);
return store;
}
}
}
Super.java
public class Super {
private int id;
private String fabricant;
private String nom;
private float preu;
private int stock;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFabricant() {
return fabricant;
}
public void setFabricant(String fabricant) {
this.fabricant = fabricant;
}
public String getNom() {
return nom;
}
public void setNom(String nom) {
this.nom = nom;
}
public float getPreu() {
return preu;
}
public void setPreu(float preu) {
this.preu = preu;
}
public int getStock() {
return stock;
}
public void setStock(int stock) {
this.stock = stock;
}
}
LongAsyncTask.java
public class LongAsyncTask extends AsyncTask<String,String,String>{
@Override
protected String doInBackground(String... arg0) {
return null;
}
protected void onPostExecute(String result) {
}
}
SuperAdapter.java
public class SuperAdapter extends BaseAdapter {
public ArrayList<Super> getItems_producte() {
return items_producte;
}
private Activity activity;
private ArrayList<Super> items_producte;
public SuperAdapter(Activity activity, ArrayList<Super> items_producte){
this.activity = activity;
this.items_producte= items_producte;
}
@Override
public int getCount() {
if(items_producte==null){
return 0;
}
else{
return items_producte.size();
} }
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return items_producte.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View contentView, ViewGroup Parent) {
// TODO Auto-generated method stub
View view = contentView;
if(view==null){
LayoutInflater inflate =(LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflate.inflate(R.layout.info_product, null,false);
}
Super item_producte = items_producte.get(position);
TextView id = (TextView)view.findViewById(R.id.list_product_id);
TextView fabricant = (TextView)view.findViewById(R.id.list_product_fabricant);
TextView nom = (TextView)view.findViewById(R.id.list_product_nom);
TextView preu = (TextView)view.findViewById(R.id.list_product_preu);
TextView stock = (TextView)view.findViewById(R.id.list_product_stock);
id.setText(Integer.toString(item_producte.getId()));
fabricant.setText(item_producte.getFabricant());
nom.setText(item_producte.getNom());
preu.setText(Float.toString(item_producte.getPreu()));
stock.setText(Integer.toString(item_producte.getStock()));
fabricant.setTextColor(activity.getResources().getColor(R.color.fabricant));
nom.setTextColor(activity.getResources().getColor(R.color.fabricant));
preu.setTextColor(activity.getResources().getColor(R.color.fabricant));
stock.setTextColor(activity.getResources().getColor(R.color.fabricant));
if(position%2==0){
view.setBackgroundColor(activity.getResources().getColor(R.color.files_parelles));
}
else{
view.setBackgroundColor(activity.getResources().getColor(R.color.files_imparelles));
}
/*STOCK COLOR*/
if(item_producte.getStock()<=0){
view.setBackgroundColor(activity.getResources().getColor(R.color.stock_null_bg));
fabricant.setTextColor(activity.getResources().getColor(R.color.stock_null_tx));
nom.setTextColor(activity.getResources().getColor(R.color.stock_null_tx));
preu.setTextColor(activity.getResources().getColor(R.color.stock_null_tx));
stock.setTextColor(activity.getResources().getColor(R.color.stock_null_tx));
}
return view;
}
public void setItems_producte(ArrayList<Super> items_producte) {
this.items_producte = items_producte;
this.notifyDataSetChanged();
}
}
The main problem is located in this section:
private void refreshListByJson(String json){//line 300
lDialog.dismiss();
Store store=Store.newStore(json);
if (store.getProductes() != null)
{
Log.i("store-nom", "" + store.getStore());//line 305
Log.i("store-producte", "" + store.getProductes().toString()); //line 306
adapter_super.setItems_producte(store.getProductes());
}
}
The "if" condition is not fulfilled: store.getProductes() is null.
It's strange because the app can DL the info from internet and I can see that in the logcat output: for some reason it doesn't load into the ArrayList.
Could you please help me in figuring out what I must do for the ArrayList to work?
Thank you very much.
