How to Post Data to API using Volley in Android?

  Using  Post Method Send data to server and Retrieve Data from Server :

Activity Main.XML Code :

<?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"
    tools:context=".MainActivity">

    <!--edit text field for adding name-->
    <EditText
        android:id="@+id/idEdtName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:layout_marginTop="40dp"
        android:hint="Enter your name" />

    <!--edit text for adding job-->
    <EditText
        android:id="@+id/idEdtJob"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="Enter your job" />

    <!--button for adding data-->
    <Button
        android:id="@+id/idBtnPost"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:text="Send Data to API"
        android:textAllCaps="false" />

    <!--text view for displaying our API response-->
    <TextView
        android:id="@+id/idTVResponse"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:gravity="center_horizontal"
        android:text="Response"
        android:textAlignment="center"
        android:textSize="15sp" />

    <!--progress bar for loading -->
    <ProgressBar
        android:id="@+id/idLoadingPB"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:visibility="gone" />

</LinearLayout>

Activity Main.java Activity code :

package com.like.exampleofvollygetreqest;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

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

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

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {

    // creating variables for our edittext,
    // button, textview and progressbar.
    private EditText nameEdt, jobEdt;
    private Button postDataBtn;
    private TextView responseTV;
    private ProgressBar loadingPB;

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

        // initializing our views
        nameEdt = findViewById(R.id.idEdtName);
        jobEdt = findViewById(R.id.idEdtJob);
        postDataBtn = findViewById(R.id.idBtnPost);
        responseTV = findViewById(R.id.idTVResponse);
        loadingPB = findViewById(R.id.idLoadingPB);

        // adding on click listener to our button.
        postDataBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // validating if the text field is empty or not.
                if (nameEdt.getText().toString().isEmpty() && jobEdt.getText().toString().isEmpty()) {
                    Toast.makeText(MainActivity.this,
                            "Please enter both the values", Toast.LENGTH_SHORT).show();
                    return;
                }
                // calling a method to post the data and passing our name and job.
                postDataUsingVolley(nameEdt.getText().toString(), jobEdt.getText().toString());
            }
        });
    }

    private void postDataUsingVolley(String name, String job) {
        // url to post our data
        String url = "https://reqres.in/api/users";
        loadingPB.setVisibility(View.VISIBLE);

        // creating a new variable for our request queue
        RequestQueue queue = Volley.newRequestQueue(MainActivity.this);

        // on below line we are calling a string
        // request method to post the data to our API
        // in this we are calling a post method.
        StringRequest request = new StringRequest(Request.Method.POST,
                url, new com.android.volley.Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                // inside on response method we are hiding our progress bar;
                // and setting data to edit text as empty
                loadingPB.setVisibility(View.GONE);
                nameEdt.setText("");
                jobEdt.setText("");

                // on below line we are displaying a success toast message.
                Toast.makeText(MainActivity.this, "Data added to API", Toast.LENGTH_SHORT).show();
                try {
                    // on below line we are parsing the responsee to json object to extract data from that json object and show on textView.
                    JSONObject respObj = new JSONObject(response);

                    // below are the strings which we extract from our json object.
                    String name = respObj.getString("name");
                    String job = respObj.getString("job");
                    //now our responce come from server ;
                    // on below line we are setting this string s to our text view.
                    responseTV.setText("Name : " + name + "\n" + "Job : " + job);
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new com.android.volley.Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                // method to handle errors.
                Toast.makeText(MainActivity.this, "Fail to get response = " + error, Toast.LENGTH_SHORT).show();
            }
        }) {
     //note : The paramenters can be set in a volley request by overriding getParams() method of Request<T> class. 
     // But the problem is that the getParams() is called only in the case of POST or PUT request. As the documentation says:       
            @Override
            protected Map<String, String> getParams() {
                // below line we are creating a map for storing our values in key and value pair.
                Map<String, String> params = new HashMap<String, String>();

                // on below line we are passing our key and value pair to our parameters.
                params.put("name", name);
                params.put("job", job);

                // at last we are
                // returning our params.
                return params;
            }
        };
        // below line is to make
        // a json object request.
        queue.add(request);
    }
}