Passing volley response to listview using an ArrayAdapter

Question

I'm unable to figure out how to pass the volley response to the listview using the adapter(myadapter). Do I use myadapter.add() and pass it what? I read tutorials and after weeks trying, I think it's time to seek help. So if you have time, I'm grateful if you can help me out. Thanks. I'm able to show response in the textview.

  package hfad.com.adapters;


    import android.app.Activity;
    import android.os.Bundle;
    import android.util.Log;
    import android.widget.ArrayAdapter;
    import android.widget.ListView;
    import android.widget.TextView;

    import com.android.volley.RequestQueue;
    import com.android.volley.Response;
    import com.android.volley.VolleyError;
    import com.android.volley.toolbox.JsonArrayRequest;
    import com.android.volley.toolbox.Volley;

    import org.json.JSONArray;
    import org.json.JSONException;
    import org.json.JSONObject;
    public class MainActivity extends Activity {

        //thorntech.com parsing jsonandroid using colley library
        TextView results;
        // URL of object to be parsed
        String JsonURL = "https://raw.githubusercontent.com/ianbar20/JSON-Volley-Tutorial/master/Example-JSON-Files/Example-Array.JSON";
        // This string will hold the results
        String data = "";
        // Defining the Volley request queue that handles the URL request concurrently

        ListView myList;

        RequestQueue requestQueue;

        //Adding adapter and assign it -set- to a listview



        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            // Creates the Volley request queue
            requestQueue = Volley.newRequestQueue(this);

            // Casts results into the TextView found within the main layout XML with id jsonData
            results = (TextView) findViewById(R.id.textView);
            myList = (ListView) findViewById(R.id.listv);
            final ArrayAdapter<String> myAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1);
            ListView myList = (ListView) findViewById(R.id.listv);
            myList.setAdapter(myAdapter);

            // Creating the JsonArrayRequest class called arrayreq, passing the required parameters
            //JsonURL is the URL to be fetched from
            JsonArrayRequest arrayreq = new JsonArrayRequest(JsonURL,
                    // The second parameter Listener overrides the method onResponse() and passes
                    //JSONArray as a parameter
                    new Response.Listener<JSONArray>() {

                        // Takes the response from the JSON request
                        @Override
                        public void onResponse(JSONArray response) {


                     //Juan suggestion:
                     ArrayList<String> myArraylist
                    myArraylist = new ArrayList<String>();

            }}

My mainactivity.xml: includes a textview and listview.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp"
    tools:context=".MainActivity"
    android:weightSum="1">


    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

   <ListView
       android:id="@+id/listv"
       android:layout_width="match_parent"
       android:layout_height="89dp"/>


</LinearLayout>

My question is how to pass the response from volley to the listview using an arrayadapter?

Answer 1

In here:

 public void onResponse(JSONArray response) {

 }

You should go through the JSONArray and extract each String and put into an ArrayList<String>.

ArrayList<String> stringsFromJson = new ArrayList<>();

And then, also in the same place, you set the values to your adapter:

myAdapter.clear();
myAdapter.addAll(stringsFromJson); 
myAdapter.notifyDataSetChanged();

Also, your adapter should be defined as ArrayAdapter<String>.

EDIT 1

Some things you need to consider:

1. You must add INTERNET Permission to your manifest
2. In the code you pasted you are not actually sending the request to the sever. For that you need to add your request to the request queue.
3. The JSON you are fetching is not just a list of strings so depending on what you want to show you may have to make changes to the listview's layout, adapter, and/or the way you populate the arraylist behind the adapter.

To provide an example I am choosing the simple alternative of populating the listview with name of the shapes. You can experiment and change for other alternatives.

Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.apackagename.so_43691098">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar">

        <activity android:name="SO_43691098">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Main Activity

package com.apackagename.so_43691098;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.JsonRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;


public class SO_43691098 extends AppCompatActivity {

        private static final String TAG = SO_43691098.class.getSimpleName();

        //thorntech.com parsing jsonandroid using colley library
        TextView results;
        // URL of object to be parsed
        String JsonURL = "https://raw.githubusercontent.com/ianbar20/JSON-Volley-Tutorial/master/Example-JSON-Files/Example-Array.JSON";
        // This string will hold the results
        String data = "";
        // Defining the Volley request queue that handles the URL request concurrently

        ListView myList;

        RequestQueue requestQueue;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main_activity);
            // Creates the Volley request queue
            requestQueue = Volley.newRequestQueue(this);

            // Casts results into the TextView found within the main layout XML with id jsonData
            results = (TextView) findViewById(R.id.textView);
            myList = (ListView) findViewById(R.id.listv);
            final ArrayAdapter<String> myAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1);
            ListView myList = (ListView) findViewById(R.id.listv);
            myList.setAdapter(myAdapter);

            // Creating the JsonArrayRequest class called arrayreq, passing the required parameters
            //JsonURL is the URL to be fetched from
            JsonArrayRequest arrayRequest = new JsonArrayRequest(JsonURL,
                    new Response.Listener<JSONArray>(){

                        @Override
                        public void onResponse(JSONArray response) {
                            //Juan suggestion:
                            ArrayList<String> myArrayList = new ArrayList<>();

                            try {
                                JSONArray shapes = response.getJSONObject(1).getJSONArray("shapeArray");
                                for(int i=0; i<shapes.length(); i++) {
                                    myArrayList.add(shapes.getJSONObject(i).getString("shapeName"));
                                }
                            } catch (JSONException e){
                                    Log.e(TAG, "Getting shape name", e);
                            }

                            myAdapter.clear();
                            myAdapter.addAll(myArrayList);
                            myAdapter.notifyDataSetChanged();
                        }
                    },
                    new Response.ErrorListener(){

                        @Override
                        public void onErrorResponse(VolleyError error) {
                            Log.e(TAG, error.getMessage(), error);
                        }
                    }
            );

            requestQueue.add(arrayRequest);

        }
}

I made no changes to the layout.