Parse JSON And Show In Listview Retrieve/Fetch URL Server " No Data "

Question

I have a problem while parsing from JSON to Listview in Android. This is an example of data from JSON:

{
    "status": {
        "statusCode": 200,
        "success": true,
        "message": "Success"
    },
    "demandes": [{
            "id": "1",
            "dateCreation": "21/01/2014",
            "tagDemand": "xxxxxxxxxxxx",
            "descDemande": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
            "imageUrl": "https://picsum.photos/3800/50/?image=1"
        },
        {
            "id": "2",
            "dateCreation": "15/01/2017",
            "tagDemand": "yyyyyyyyyyyyyyyyyyyy",
            "descDemande": "yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy",
            "imageUrl": "https://picsum.photos/3500/5200/?image=221"
        }
    ]
}

This is the main activity:

public class MyRequests extends AppCompatActivity {

private String jsonURL = "https://26ae7d0d-62b2-4cc4-8ff7-009bee255089.mock.pstmn.io/demands";
private final int jsoncode = 1;
private ListView listView;
ArrayList<DemandeModel> demandeModelArrayList;
private DemandeAdapter demandeAdapter;
String response = "";


private static ProgressDialog mProgressDialog;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_requests);
    listView = findViewById(R.id.lv);
    fetchJSON();
}

@SuppressLint("StaticFieldLeak")
private void fetchJSON() {

    showSimpleProgressDialog(this, "Chargement...", "Récupération des données", false);

    new AsyncTask<Void, Void, String>() {
        protected String doInBackground(Void[] params) {
            //  String response="";
            HashMap<String, String> map = new HashMap<>();
            try {
                HttpRequest req = new HttpRequest(jsonURL);
                response = req.prepare(HttpRequest.Method.POST).withData(map).sendAndReadString();
            } catch (Exception e) {
                response = e.getMessage();
            }
            return response;
        }

        protected void onPostExecute(String result) {
            //do something with response
            Log.d("newwwss", result);
            onTaskCompleted(result, jsoncode);
        }
    }.execute();
}

public void onTaskCompleted(String response, int serviceCode) {
    Log.d("responsejson", response.toString());
    switch (serviceCode) {
        case jsoncode:
            if (isSuccess(response)) {
                removeSimpleProgressDialog();  //will remove progress dialog
                demandeModelArrayList = getInfo(response);
                demandeAdapter = new DemandeAdapter(this, demandeModelArrayList);
                listView.setAdapter(demandeAdapter);

            } else {
                Toast.makeText(MyRequests.this, getErrorCode(response), Toast.LENGTH_SHORT).show();
            }
    }
}

public ArrayList<DemandeModel> getInfo(String response) {
    ArrayList<DemandeModel> demandeModelArrayList = new ArrayList<>();
    try {
        JSONObject jsonObject = new JSONObject(response);
        if (jsonObject.getJSONObject("status").optString("success").equals("true")) {

            JSONArray dataArray = jsonObject.getJSONArray("demandes");

            for (int i = 0; i < dataArray.length(); i++) {
                DemandeModel playersModel = new DemandeModel();
                JSONObject dataobj = dataArray.getJSONObject(i);
                playersModel.setId(dataobj.getString("id"));
                playersModel.setDate(dataobj.getString("dateCreation"));
                playersModel.setNom(dataobj.getString("tagDemand"));
                playersModel.setDescription(dataobj.getString("descDemande"));
                playersModel.setImgURL(dataobj.getString("imageUrl"));
                demandeModelArrayList.add(playersModel);

            }
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return demandeModelArrayList;
}


public boolean isSuccess(String response) {

    try {
        JSONObject jsonObject = new JSONObject(response);
        if (jsonObject.getJSONObject("status").optString("success").equals("true")) {
            return true;
        } else {

            return false;
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return false;
}

public String getErrorCode(String response) {

    try {
        JSONObject jsonObject = new JSONObject(response);
        return jsonObject.getJSONObject("status").optString("message");

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return "No data";
}

public static void removeSimpleProgressDialog() {
    try {
        if (mProgressDialog != null) {
            if (mProgressDialog.isShowing()) {
                mProgressDialog.dismiss();
                mProgressDialog = null;
            }
        }
    } catch (IllegalArgumentException ie) {
        ie.printStackTrace();

    } catch (RuntimeException re) {
        re.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }

}

public static void showSimpleProgressDialog(Context context, String title,
                                            String msg, boolean isCancelable) {
    try {
        if (mProgressDialog == null) {
            mProgressDialog = ProgressDialog.show(context, title, msg);
            mProgressDialog.setCancelable(isCancelable);
        }

        if (!mProgressDialog.isShowing()) {
            mProgressDialog.show();
        }

    } catch (IllegalArgumentException ie) {
        ie.printStackTrace();
    } catch (RuntimeException re) {
        re.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

}

so, I had like a response "no data" so I think that there is a problem here " if (isSuccess(response)) "

This is my Adapter:

public class DemandeAdapter extends BaseAdapter {

    private Context context;
    private ArrayList<DemandeModel> demandeModelArrayList;

    public DemandeAdapter(Context context, ArrayList<DemandeModel> demandeModelArrayList) {

        this.context = context;
        this.demandeModelArrayList = demandeModelArrayList;
    }

    @Override
    public int getViewTypeCount() {
        return getCount();
    }
    @Override
    public int getItemViewType(int position) {

        return position;
    }

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

    @Override
    public Object getItem(int position) {
        return demandeModelArrayList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            holder = new ViewHolder();
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.demande, null, true);

            holder.iv = (ImageView) convertView.findViewById(R.id.iv);
            holder.id = (TextView) convertView.findViewById(R.id.id);
            holder.name = (TextView) convertView.findViewById(R.id.name);
            holder.desc = (TextView) convertView.findViewById(R.id.desc);
            holder.date = (TextView) convertView.findViewById(R.id.date);

            convertView.setTag(holder);
        }else {
            // the getTag returns the viewHolder object set as a tag to the view
            holder = (ViewHolder)convertView.getTag();
        }

        Picasso.get().load(demandeModelArrayList.get(position).getImgURL()).into(holder.iv);
        holder.id.setText("ID : "+demandeModelArrayList.get(position).getId());
        holder.date.setText("Date : "+demandeModelArrayList.get(position).getDate());
        holder.name.setText("Name : "+demandeModelArrayList.get(position).getNom());
        holder.desc.setText("Description : "+demandeModelArrayList.get(position).getDescription());

        return convertView;
    }

    private class ViewHolder {

        protected TextView id,name,desc,date;
        protected ImageView iv;
    }

}

and this is my Model:

public class DemandeModel {

    private String id;
    private String nom;
    private String description;
    private String date;
    private String imgURL;


    public DemandeModel() {
    }

    public DemandeModel(String id, String nom, String description, String date, String imgURL) {
        this.id = id;
        this.nom = nom;
        this.description = description;
        this.date = date;
        this.imgURL = imgURL;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getNom() {
        return nom;
    }

    public void setNom(String nom) {
        this.nom = nom;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getImgURL() {
        return imgURL;
    }

    public void setImgURL(String imgURL) {
        this.imgURL = imgURL;
    }
}

And this is the HttpRequest :

public class HttpRequest {
public static enum Method {
    POST, PUT, DELETE, GET;
}

private URL url;
private HttpURLConnection con;
private OutputStream os;

//After instantiation, when opening connection - IOException can occur
public HttpRequest(URL url) throws IOException {
    this.url = url;
    con = (HttpURLConnection) this.url.openConnection();
}

//Can be instantiated with String representation of url, force caller to check for IOException which can be thrown
public HttpRequest(String url) throws IOException {
    this(new URL(url));
    Log.d("parameters", url);
}

/**
 * Sending connection and opening an output stream to server by pre-defined instance variable url
 *
 * @param //isPost boolean - indicates whether this request should be sent in POST method
 * @throws IOException - should be checked by caller
 */
private void prepareAll(Method method) throws IOException {
    con.setDoInput(true);
    con.setRequestMethod(method.name());
    if (method == Method.POST || method == Method.PUT) {
        con.setDoOutput(true);
        os = con.getOutputStream();
    }
}

//prepare request in GET method
//@return HttpRequest this instance -> for chaining method @see line 22
public HttpRequest prepare() throws IOException {
    prepareAll(Method.GET);
    return this;
}

/**
 * Prepares HttpRequest method with for given method, possible values: HttpRequest.Method.POST,
 * HttpRequest.Method.PUT, HttpRequest.Method.GET & HttpRequest.Method.DELETE
 *
 * @param method HttpRequest.Method - nested enum HttpRequest.Method constant
 * @return HttpRequest this instance -> for chaining method @see line 22
 * @throws IOException - should be checked by caller
 */
public HttpRequest prepare(Method method) throws IOException {
    prepareAll(method);
    return this;
}

/**
 * Adding request headers (standard format "Key":"Value")
 *
 * @param headers String variadic params in standard format "Key":"Value"
 * @return HttpRequest this instance -> for chaining method @see line 22
 */
public HttpRequest withHeaders(String... headers) {
    for (int i = 0, last = headers.length; i < last; i++) {
        String[] h = headers[i].split("[:]");
        con.setRequestProperty(h[0], h[1]);
    }
    return this;
}

/**
 * Writes query to open stream to server
 *
 * @param query String params in format of key1=v1&key2=v2 to open stream to server
 * @return HttpRequest this instance -> for chaining method @see line 22
 * @throws IOException - should be checked by caller
 */
public HttpRequest withData(String query) throws IOException {
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
    writer.write(query);
    writer.close();
    return this;
}

/**
 * Builds query on format of key1=v1&key2=v2 from given hashMap structure
 * for map: {name=Bubu, age=29} -> builds "name=Bubu&age=29"
 * for map: {Iam=Groot} -> builds "Iam=Groot"
 *
 * @param params HashMap consists of key-> value pairs to build query from
 * @return HttpRequest this instance -> for chaining method @see line 22
 * @throws IOException - should be checked by caller
 */
public HttpRequest withData(HashMap<String, String> params) throws IOException {
    StringBuilder result = new StringBuilder();
    for (Map.Entry<String, String> entry : params.entrySet()) {
        result.append((result.length() > 0 ? "&" : "") + entry.getKey() + "=" + entry.getValue());//appends: key=value (for first param) OR &key=value(second and more)
        Log.d("parameters", entry.getKey() + "  ===>  " + entry.getValue());
    }
    withData(result.toString());
    return this;
}

//When caller only need to send, and don't need String response from server
public int send() throws IOException {
    return con.getResponseCode(); //return HTTP status code to indicate whether it successfully sent
}

/**
 * Sending request to the server and pass to caller String as it received in response from server
 *
 * @return String printed from server's response
 * @throws IOException - should be checked by caller
 */
public String sendAndReadString() throws IOException {
    BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
    StringBuilder response = new StringBuilder();
    for (String line; (line = br.readLine()) != null; ) response.append(line + "\n");
    Log.d("ressss", response.toString());
    return response.toString();
}

/**
 * Sending request to the server and pass to caller its raw contents in bytes as it received from server.
 *
 * @return byte[] from server's response
 * @throws IOException - should be checked by caller
 */
public byte[] sendAndReadBytes() throws IOException {
    byte[] buffer = new byte[8192];
    InputStream is = con.getInputStream();
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    for (int bytesRead; (bytesRead = is.read(buffer)) >= 0; ) output.write(buffer, 0, bytesRead);
    return output.toByteArray();
}

//JSONObject representation of String response from server
public JSONObject sendAndReadJSON() throws JSONException, IOException {
    return new JSONObject(sendAndReadString());
}
}

if someone could hepl to solve this problem it will be with a pleasure

Answer 1

I have updated the parsing method. Check below

public ArrayList<DemandeModel> getInfo(String response) {
    ArrayList<DemandeModel> demandeModelArrayList = new ArrayList<>();
    try {
        JSONObject jsonObject = new JSONObject(response);
        if (jsonObject.getJSONObject("status").optString("success").equals("true")) {

            JSONArray dataArray = jsonObject.getJSONArray("demandes");

            for (int i = 0; i < dataArray.length(); i++) {
                DemandeModel playersModel = new DemandeModel();
                JSONObject dataobj = dataArray.getJSONObject(i);
                playersModel.setId(dataobj.getString("id"));
                playersModel.setDate(dataobj.getString("dateCreation"));
                playersModel.setNom(dataobj.getString("tagDemand"));
                playersModel.setDescription(dataobj.getString("descDemande"));
                playersModel.setImgURL(dataobj.getString("imageUrl"));
                demandeModelArrayList.add(playersModel);

            }
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return demandeModelArrayList;
}

EDIT below method is updated a bit

public boolean isSuccess(String response) {

    try {
        JSONObject jsonObject = new JSONObject(response);
        if (jsonObject.getJSONObject("status").optString("success").equals("true")) {
            return true;
        } else {

            return false;
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return false;
}

EDIT 2

change below line

response = req.prepare(HttpRequest.Method.POST).withData(map).sendAndReadString();

to

response = req.prepare().sendAndReadString();

Answer 2

It looks like you are reading wrong data:

jsonObject.getString("status").equals("true")

There is no "status" in your json respose example. There is "success".