11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err: org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at org.json.JSON.typeMismatch(JSON.java:111)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at org.json.JSONObject.<init>(JSONObject.java:160)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at org.json.JSONObject.<init>(JSONObject.java:173)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.techrefic.app1611.MainActivity$2.onResponse(MainActivity.java:178)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.techrefic.app1611.MainActivity$2.onResponse(MainActivity.java:172)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:67)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at android.os.Handler.handleCallback(Handler.java:739)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at android.os.Looper.loop(Looper.java:148)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5417)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
11-18 13:27:23.766 30362-30362/com.techrefic.app1611 W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
11-18 13:27:23.776 1620-1943/system_process W/InputMethodManagerService: Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@7b87dab attribute=null, token = android.os.BinderProxy@ba60539
11-18 13:27:26.741 1317-1603/? W/audio_hw_generic: Not supplying enough data to HAL, expected position 5574322 , only wrote 5436064
11-18 13:28:00.085 1212-1272/? D/hwcomposer: hw_composer sent 84 syncs in 60s
11-18 13:29:00.061 1212-1272/? D/hwcomposer: hw_composer sent 4 syncs in 60s

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

      //    Creating views
      private EditText editTextEmail;
    private EditText editTextPassword;
    private EditText editTextPhone;
    private EditText editTextConfirmOtp;

    private AppCompatButton buttonRegister;
    private AppCompatButton buttonConfirm;

    //Volley RequestQueue
    private RequestQueue requestQueue;

    //String variables to hold email, password and phone number
    private String username;
    private String password;
    private String phone;

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

        //Initializing Views
        editTextEmail = (EditText) findViewById(R.id.editTextEmail);
        editTextPassword = (EditText) findViewById(R.id.editTextPassword);
        editTextPhone = (EditText) findViewById(R.id.editTextPhone);

        buttonRegister = (AppCompatButton) findViewById(R.id.buttonRegister);

       //Initializing the RequestQueue
        requestQueue = Volley.newRequestQueue(this);

       //Adding a listener to button
        buttonRegister.setOnClickListener((View.OnClickListener) this);
    }

//    This method would confirm the OTP

    private void confirmOtp() throws JSONException {

        //Creating a Layout Inflater object for the dialog box
        LayoutInflater li = LayoutInflater.from(this);

        //Creating a view to get the dialog box

        View confirmDialog = li.inflate(R.layout.dialog_confirm, null);

//        Initialing confirm button for dialog box and edittext of dialog box

        buttonConfirm = (AppCompatButton) confirmDialog.findViewById(R.id.buttonConfirm);
        editTextConfirmOtp = (EditText) confirmDialog.findViewById(R.id.editTextOtp);

        //Creating an alert dialog builder
        AlertDialog.Builder alert = new AlertDialog.Builder(this);

        //Adding our dialog box to the view of alert dialog
        alert.setView(confirmDialog);

        //Creating an alert dialog
        final AlertDialog alertDialog = alert.create();

        //Displaying the alert dialog
        alertDialog.show();

//        Onclick of the confirm button from alert dialog
        buttonConfirm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Hiding the alert dialog
                alertDialog.dismiss();

                //Displaying a progressbar
                final ProgressDialog loading = ProgressDialog.show(MainActivity.this, "Authenticating ", "Please wait while we check the entered code", false, false);

                //Getting the user entered otp from edittext
                final String otp = editTextConfirmOtp.getText().toString().trim();

                //Creating an string request
                StringRequest stringRequest = new StringRequest(Request.Method.POST, Config.CONFIRM_URL,
                        new Response.Listener<String>() {
                            @Override
                            public void onResponse(String response) {
                                if (response.equalsIgnoreCase("success")) {
                                    loading.dismiss();

                                    //Start a new activity
                                    startActivity(new Intent(MainActivity.this, Success.class));
                                } else {
                                    //Displaying a toast if the otp entered is wrong
                                    Toast.makeText(MainActivity.this, "Wrong OTP Please try Again", Toast.LENGTH_LONG).show();
                                    try {
                                        //Asking user to enter otp again
                                        confirmOtp();
                                    } catch (JSONException e) {
                                        e.printStackTrace();
                                    }
                                }
                            }
                        },
                        new Response.ErrorListener() {
                            @Override
                            public void onErrorResponse(VolleyError error) {
                                alertDialog.dismiss();
                             }
                        }){

                    @Override
                    protected Map<String, String> getParams() throws AuthFailureError {
                        Map<String, String> params = new HashMap<String, String>();
                        //Adding the parameters otp and email

                        params.put(Config.KEY_OTP, otp);
                        params.put(Config.KEY_USERNAME, username);
                        return  params;
                    }
                };
                //Adding the request to the queue
                requestQueue.add(stringRequest);
            }
        });
    }


    //this method will get register the user
    private void register() {
        //Displaying a progress dialog
        final ProgressDialog loading = ProgressDialog.show(this, "Registering", "Please wait...", false, false);

        //Getting user data
        username = editTextEmail.getText().toString().trim();
        password = editTextPassword.getText().toString().trim();
        phone = editTextPhone.getText().toString().trim();

        //Again creating the request
        StringRequest stringRequest = new StringRequest(Request.Method.POST, Config.REGISTER_URL,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        loading.dismiss();
                        try {
                            //Creating the json object from the response
                            JSONObject jsonResponse = new JSONObject(response);

                            //IF it is success
                            if (jsonResponse.getString(Config.TAG_RESPONSE).equalsIgnoreCase("success")) {
                                //Asking user to confirm otp
                                confirmOtp();
                            } else {
                                //If not successful user may already have registerd
                                Toast.makeText(MainActivity.this, "Username or Phone Number already registered", Toast.LENGTH_LONG).show();
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        loading.dismiss();
                        Toast.makeText(MainActivity.this, error.getMessage(), Toast.LENGTH_LONG).show();

                    }
                }) {
            @Override
            protected Map<String, String> getParams()throws AuthFailureError {
                Map<String, String> params = new HashMap<>();
                //Adding the params to the request
                params.put(Config.KEY_USERNAME, username);
                params.put(Config.KEY_PASSWORD, password);
                params.put(Config.KEY_PHONE, phone);
                return params;
            }
        };

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

    @Override
    public void onClick(View v){
        //calling refgister method on register button click
        register();
    }
}

public class Config {

    public static final String REGISTER_URL = "http://192.168.0.4/famous/register.php";
    public static final String CONFIRM_URL = "http://192.168.0.4/famous/confirm.php";

    //Keys to send username, password, phone and otp
    public static final String KEY_USERNAME = "username";
    public static final String KEY_PASSWORD = "password";
    public static final String KEY_PHONE = "phone";
    public static final String KEY_OTP = "otp";

    //JSON Tag from response from server
    public static final String TAG_RESPONSE= "ErrorMessage";
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

    compile 'com.android.support:design:26.1.0'
    compile 'com.mcxiaoke.volley:library:1.0.19'
}

<?php
// Constants for our API
// this is applicable only when you are using SMS API
define('SMSUSER', $_POST[username]);
define('PASSWORD', $_POST[password]);
define('PHONE', $_POST[phone]);
// define('SENDERID', 'EDCRTZ');

// This function will send the otp


$otp = int rand(100000, 999999);

    // This is the sms text that will be sent via sms
$sms_content = "Welcome ".SMSUSER.", to DEMO Tp RTA app: Your verification code is".$otp ;

// This is the Actual API URL concatnated with required values
     $api_url ="http://mymessageapi".$sms_content."&senderId=EDCRTZ&routeId=1&mobileNos=".PHONE."&smsContentType=english";


//Envoking the API url and getting the response
$response = file_get_contents($api_url);

//Returning the response
return $response;

//If a past request comes to this script
if ($_SERVER['REQUEST_METHOD']=='POST') {
// getting username password and phone number
    $username = $_POST['username'];
    $password = $_POST['password'];
    $phone = $_POST['phone'];

//Generating a 6 digits OTP or verification code
$otp = rand(100000, 999999);


    //Importing the db connection script

require_once('dbConnect.php');

//Creating an SQL Query
$sql = "INSERT INTO famous (username, password, phone, otp) values('$username','$password','$phone','$otp')";

//If the query executed on the db successfully
if (mysql_query($con,$sql)) {
    // printing the failure message in json
echo '{"ErrorMessage":"Failure"}';
}
//Closing the databse connection
mysqli_close($con);
}
?>

<?php

//If a post request is detected
if ($_SERVER['REQUEST_METHOD']=='POST') {

    //gETTING THE username and otp
$username = $_POST['username'];
$otp = $_POST['otp'];


// Importing the dbConnect script
require_once('dbConnect.php');

//Creating an SQL to fetch the otp from the table
$sql = "SELECT otp FROM test-table WHERE username = '$username'";

//Getting the result array from databse
$result = mysqli_fetch_array(mysqli_query($con,$sql));

//Getting the otp from the array
 $realotp = $result['otp'];

//Getting the otp given is equal to otp fetched from database
if ($otp == $realotp) {
// Creating an sql query to update the column verified to 1 for the specified user

$sql = "UPDATE test-table SET verified= '1' WHERE username ='$username'";

//If the table is updated
if (mysqli_query($con,$sql)) {
        //displaying failure
echo 'success';
}else{
    //displaying failure
    echo "failure";
}
}else{
    //displaying failure if otp is not equal to the otp fetched from databse
    echo 'failure';
}
//Closing the database
mysql_close($con);

}
?>

<?php
 define('HOST', 'localhost');
 define('USER', 'root');
 define('PASS', '');
 define('DB', 'famous');

 //connecting to database
 $con = mysqli_connect(HOST, USER, PASS, DB) or die('Unable to Connect');
 ?>