the textviews are not loading from json

Question

I just need help with a situation where i have to load data from remote server and i am using volley library for the purpose of fetching the values from the server so this is what i have done so far

public class Leaderboard extends AppCompatActivity {
private ListView leaderListView;
private ProgressDialog loading;
private TextView myname,myrank,myaccu;
public static final String ROOT_URL = "http://thehostels.in/judgement_files/";

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

    myname=(TextView)findViewById(R.id.myname);
    myrank=(TextView)findViewById(R.id.myrank);
    myaccu=(TextView)findViewById(R.id.myAccuracy);
    getMe();


}

 User user = SharedPrefManager.getInstance(Leaderboard.this).getUser();
 String userEmail= user.getEmail();

public void getMe(){


        loading = ProgressDialog.show(this,"","",false,false);
        String url = Config.Leaderboard.toString().trim();


        StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                loading.dismiss();
                showJSON(response);
            }
        },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        loading.dismiss();
                    }
                });

        RequestQueue requestQueue = Volley.newRequestQueue(this);
        requestQueue.add(stringRequest);
    }

private void showJSON(String response){
    String textname="";
    String textrank="";
    String textacc="";
    String val1="";
    String val2="";


    try {
        JSONObject jsonObject = new JSONObject(response);
        JSONArray result = jsonObject.getJSONArray(Config.JSON_ARRAY_Leader);
        JSONObject TeamData = result.getJSONObject(0);
        textname = TeamData.getString(Config.myname);
        textrank = TeamData.getString(Config.myrank);
        textacc = TeamData.getString(Config.myaccuracy);
        val1=("#"+textrank+".");
        val2=(textacc+"%");

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

    myrank.setText(val1);
    myname.setText(textname);
    myaccu.setText(val2);
}

   public void sendEmail(){


    RestAdapter adapter = new RestAdapter.Builder()
            .setEndpoint(ROOT_URL) //Setting the Root URL
            .build(); //Finally building the adapter

    //Creating object for our interface
    myEmail api = adapter.create(myEmail.class);

    //Defining the method insertuser of our interface
    api.sendMail(

            userEmail,
            //Creating an anonymous callback
            new Callback<retrofit.client.Response>() {
                @Override
                public void success(retrofit.client.Response result, retrofit.client.Response response) {
                    //On success we will read the server's output using bufferedreader
                    //Creating a bufferedreader object
                    BufferedReader reader = null;

                    //An string to store output from the server
                    String output = "";

                    try {
                        //Initializing buffered reader
                        reader = new BufferedReader(new InputStreamReader(result.getBody().in()));

                        //Reading the output in the string
                        output = reader.readLine();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                    //Displaying the output as a toast
                    Toast.makeText(Leaderboard.this, output, Toast.LENGTH_LONG).show();


                }

                @Override
                public void failure(RetrofitError error) {
                    //If any error occured displaying the error as toast
                    Toast.makeText(Leaderboard.this, "something went wrong", Toast.LENGTH_LONG).show();
                }
            }
    );
}

and config.java file

public class Config {
    public static final String Leaderboard = "http://thehostels.in/judgement_files/myleaderboard.php";
    public static final String myname = "name";
    public static final String myrank = "rank";
    public static final String myaccuracy = "accuracy";
    public static final String JSON_ARRAY_Leader= "list";
    }

myleaderboard.php

<?php
  if($_SERVER['REQUEST_METHOD']=='POST'){
     $email=$_POST['userEmail'];
      define('HOST','xxxxxxxx');
      define('USER','xxxxxxxx');
      define('PASS','xxxxxxxx');
      define('DB','xxxxxxxx');

      $con = mysqli_connect(HOST,USER,PASS,DB) or die('Unable to Connect');

      $sql = "select * from Leaderboard where email='$email'";

      $res = mysqli_query($con,$sql);
      $result = array();
      while($row = mysqli_fetch_array($res)){
      array_push($result,
      array('name'=>$row[1],
      'rank'=>$row[2],
      'accuracy'=>$row[3]));
       }
      echo json_encode (array("list"=>$result));
        }
       mysqli_close($con);

        }
           ?>

my json returns me

  {"list":[{"name":"Vipul S","rank":"1","accuracy":"80"}]}

main file which contains textviews leaderboard.xml

        <RelativeLayout 
     xmlns:android="http://schemas.android.com/apk/res/android"
    android:padding="3sp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

<funplay.dreamstar1.CustomTextView
    android:layout_marginLeft="10sp"
    android:layout_marginStart="10sp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@color/black"
    android:text="#1"
    android:layout_marginTop="20sp"
    android:textSize="17sp"
    android:id="@+id/myrank"/>

<funplay.dreamstar1.CustomTextView
    android:layout_marginLeft="35sp"
    android:layout_marginStart="35sp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@color/black"
    android:text="Vipul S"
    android:layout_marginTop="20sp"
    android:textSize="17sp"
    android:id="@+id/myname"/>

<funplay.dreamstar1.CustomTextView
    android:layout_marginEnd="12sp"
    android:layout_marginRight="12sp"
    android:layout_alignParentEnd="true"
    android:layout_alignParentRight="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@color/black"
    android:text="100%"
    android:layout_marginTop="20sp"
    android:textSize="17sp"
    android:id="@+id/myAccuracy"/>

so the thing is MySQL table contains many columns and i just wanna retrieve few columns from that table and encode in json to get it back to my android code but somehow it is not happening and data is not populating in textview and i have debug the PHP code its working all fine.

here sendEmail function is used to send email from android to myleaderboard.php file which then only chooses the row with matching email so i just wanna know what is problem over here or is there any alternative way to do so....

Answer 1

Given below is the json you are getting back from your php. (I am not well versed in php to suggest any errors in your php code. But since you claim that the php code is working all fine and returning the json you want / expect.)

{
    "list": [
        {
            "name": "Vipul S",
            "rank": "1",
            "accuracy": "80"
        }
    ]
}

create the following two classes

public class MyPhpResponse {
    private List<MyPhpObject> list;

    public List<MyPhpObject> getList() {
        return list;
    }

    public void setList(List<MyPhpObject> inputList) {
        list = inputList;
    }
}

public class MyPhpObject {
    private String name;
    private String rank;
    private String accuracy;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRank() {
        return rank;
    }

    public void setRank(String rank) {
        this.rank = rank;
    }

    public String getAccuracy() {
        return accuracy;
    }

    public void setAccuracy(String accuracy) {
        this.accuracy = accuracy;
    }
}

Now use the Google's Gson library https://mvnrepository.com/artifact/com.google.code.gson/gson/2.8.2 and do the following in your showJSON method :

private void showJSON(String response) {
        try {
            final Gson gson = new Gson();
            final MyPhpResponse myPhpResponse = gson.fromJson(response, MyPhpResponse.class);
            //Assuming you are getting only one object back in the list
            final MyPhpObject myPhpObject = myPhpResponse.getList().get(0);
            myrank.setText(myPhpObject.getRank());
            myname.setText(myPhpObject.getName());
            myaccu.setText(myPhpObject.getAccuracy());
        } catch (MalformedJsonException e) {
            e.printStackTrace();
        }
    }

This should expose any issues with the JSON and if there are no issues the TextView should definitely show the data. Let me know how it works out for you.