Volley Library in Android

 1)  Add volley library in 

implementation 'com.android.volley:volley:1.1.1'

2)  Mainfest internet permission

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

3)  Create POJO CLASS or Property Class

package com.example.webviewexample;

public class Hero {
    String name, imageUrl;

    public Hero(String name, String imageUrl) {
        this.name = name;
        this.imageUrl = imageUrl;
    }

    public String getName() {
        return name;
    }

    public String getImageUrl() {
        return imageUrl;
    }
}


4)  Create CustomAdapter using LisViewAdapter

package com.example.webviewexample;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import java.util.List;

public class ListViewAdapter extends ArrayAdapter<Hero> {

    //the hero list that will be displayed
    private List<Hero> heroList;

    //the context object
    private Context mCtx;

    //here we are getting the herolist and context
    //so while creating the object of this adapter class we need to give herolist and context
    public ListViewAdapter(List<Hero> heroList, Context mCtx) {
        super(mCtx, R.layout.list_items, heroList);
        this.heroList = heroList;
        this.mCtx = mCtx;
    }

    //this method will return the list item
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        //getting the layoutinflater
        LayoutInflater inflater = LayoutInflater.from(mCtx);

        //creating a view with our xml layout
        View listViewItem = inflater.inflate(R.layout.list_items, null, true);

        //getting text views
        TextView textViewName = listViewItem.findViewById(R.id.textViewName);
        TextView textViewImageUrl = listViewItem.findViewById(R.id.textViewImageUrl);

        //Getting the hero for the specified position
        Hero hero = heroList.get(position);

        //setting hero values to textviews
        textViewName.setText(hero.getName());
        textViewImageUrl.setText(hero.getImageUrl());

        //returning the listitem
        return listViewItem;
    }
}


5)

package com.example.webviewexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

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

import java.util.ArrayList;
import java.util.List;

public class VolleyExample extends AppCompatActivity {

    private static final String JSON_URL = "https://simplifiedcoding.net/demos/view-flipper/heroes.php";

   

    //the hero list where we will store all the hero objects after parsing json
    List<Hero> heroList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_volley_example);
        listView = (ListView) findViewById(R.id.listView);
        heroList = new ArrayList<>();

        //this method will fetch and parse the data
        loadHeroList();
    }

    private void loadHeroList() {
        //getting the progressbar
        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar);

        //making the progressbar visible
        progressBar.setVisibility(View.VISIBLE);

        //creating a string request to send request to the url
        StringRequest stringRequest = new StringRequest(Request.Method.GET, JSON_URL,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        //hiding the progressbar after completion
                        progressBar.setVisibility(View.INVISIBLE);


                        try {
                            //getting the whole json object from the response
                            JSONObject obj = new JSONObject(response);

                            //we have the array named hero inside the object
                            //so here we are getting that json array
                            JSONArray heroArray = obj.getJSONArray("heroes");

                            //now looping through all the elements of the json array
                            for (int i = 0; i < heroArray.length(); i++) {
                                //getting the json object of the particular index inside the array
                                JSONObject heroObject = heroArray.getJSONObject(i);

                                //creating a hero object and giving them the values from json object
                                Hero hero = new Hero(heroObject.getString("name"), heroObject.getString("imageurl"));

                                //adding the hero to herolist
                                heroList.add(hero);
                            }

                            //creating custom adapter object
                            ListViewAdapter adapter = new ListViewAdapter(heroList, getApplicationContext());

                            //adding the adapter to listview
                            listView.setAdapter(adapter);

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        //displaying the error in toast if occurrs
                        Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });

        //creating a request queue
        RequestQueue requestQueue = Volley.newRequestQueue(this);

        //adding the string request to request queue
        requestQueue.add(stringRequest);
    }
}





Layout File


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".VolleyExample">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ProgressBar
        android:visibility="gone"
        android:id="@+id/progressBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true" />

</RelativeLayout>


7)   Design File
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textViewName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />

    <TextView
        android:id="@+id/textViewImageUrl"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:autoLink="web"
        android:textColor="#08308e" />

</LinearLayout>


Call Registration API using Volley Library?

Volley library provide simple approach to registartion page?

package com.example.webviewexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

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

import java.util.ArrayList;
import java.util.List;

public class VolleyExample extends AppCompatActivity {

    private static  String JSON_URL = "https://shivaconceptsolution.com/webservices/reg.php";

    //listview object
    ListView listView;

    //the hero list where we will store all the hero objects after parsing json
    List<Hero> heroList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_volley_example);
        listView = (ListView) findViewById(R.id.listView);
        heroList = new ArrayList<>();

        //this method will fetch and parse the data
        loadHeroList();
    }

    private void loadHeroList() {
        //getting the progressbar
        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar);

        //making the progressbar visible
        progressBar.setVisibility(View.VISIBLE);

        //creating a string request to send request to the url
        StringRequest stringRequest = new StringRequest(Request.Method.POST, JSON_URL+= "?name="+"check"+"&pwd="+"chk123"+"&email="+"chk@gmail.com",
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        //hiding the progressbar after completion
                        progressBar.setVisibility(View.INVISIBLE);


                        try {
                            //getting the whole json object from the response
                            JSONObject obj = new JSONObject(response);

                            //we have the array named hero inside the object
                            //so here we are getting that json array
                            int st = obj.getInt("status");
                           if(st!=0)
                           {
                               Toast.makeText(getApplicationContext(),"Success", Toast.LENGTH_SHORT).show();
                           }
                          else
                           {
                               Toast.makeText(getApplicationContext(),"Fail", Toast.LENGTH_SHORT).show();
                           }

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        //displaying the error in toast if occurrs
                        Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });

        //creating a request queue
        RequestQueue requestQueue = Volley.newRequestQueue(this);

        //adding the string request to request queue
        requestQueue.add(stringRequest);
    }
}