2factor SMS in Spring Boot App

Carvia Tech | July 11, 2020 | 3 min read | 87 views

Send 2factor transactional sms in Spring Boot application using Java 11 HttpClient, OkHttp Client and RestTemplate

First of all make sure that you have an active account at https://2factor.in and have SMS templates configured/approved for use. You need to get Api Key from 2factor in order to send SMS programmatically.


Creating Spring Boot project

We can quickly create a gradle based spring boot starter using https://start.spring.io/

plugins {
    id 'org.springframework.boot' version '2.3.0.RELEASE'
    id 'io.spring.dependency-management' version '1.0.9.RELEASE'
    id 'java'

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'

repositories {

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    testImplementation('org.springframework.boot:spring-boot-starter-test') {
        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'

test {

we will use three different clients to communicate to 2factor API in this tutorial:

  • Java 11 HttpClient

  • OkHttp Client

  • Spring restTemplate

Java 11 HttpClient

Java 11 ships inbuilt Java HttpClient that can be used for making remote service calls.

First of all we will create a single HttpClient bean which will be reused across components for making remote calls.

HttpClientConfig.java - Create a bean of type HttpClient
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.net.http.HttpClient;

public class HttpClientConfig {

    public HttpClient createClient() {
        HttpClient client = HttpClient.newBuilder()
        return client;

Now we will create a service that used HttpClient to send a transactional SMS using 2factor service provider.

Service.kt to send SMS
class Scratch (private val httpClient: HttpClient) {

    fun sendSms() {
        val apiKey = "<insert your api key here>"
        val data: MutableMap<String, String> = HashMap()
        data["To"] = "mobile"
        data["From"] = "SHUNYA"
        data["TemplateName"] = "TEMPLATE-NAME"
        data["VAR1"] = "1234"
        data["VAR2"] = "testhash"

        val request: HttpRequest = HttpRequest.newBuilder()
                .header("User-Agent", "Java 11 HttpClient")
                .header("Content-Type", "application/x-www-form-urlencoded")
        val response: HttpResponse<String> = httpClient.send(request, HttpResponse.BodyHandlers.ofString())


    fun ofFormData(data: Map<String, String>): BodyPublisher? {
        val builder = StringBuilder()
        for ((key, value) in data) {
            if (builder.isNotEmpty()) {
            builder.append(URLEncoder.encode(key, StandardCharsets.UTF_8))
            builder.append(URLEncoder.encode(value, StandardCharsets.UTF_8))
        return HttpRequest.BodyPublishers.ofString(builder.toString())



We will create a OkHttpClient bean that will be used across the project wherever necessary, using dependency injection.

class OkHttpConfig {

    fun okHttpClient(): OkHttpClient {
        return OkHttpClient.Builder()
                .readTimeout(60, TimeUnit.SECONDS)
                .writeTimeout(60, TimeUnit.SECONDS)

Now in order to send SMS using 2factor service provider, we will develop a component that used OkHttpClient bean to make remote service call.

Scratch.kt - service to send sms
class Scratch (private val okHttpClient: OkHttpClient){

    fun sendSms() {
        try {
            val apiKey = "<insert API key here>"
            val build = MultipartBody.Builder()
                    .addFormDataPart("To", "mobile")
                    .addFormDataPart("From", "SHUNYA")
                    .addFormDataPart("TemplateName", "TEMPLATE-NAME")
                    .addFormDataPart("VAR1", otp)
            val request = Request.Builder()

            okHttpClient.newCall(request).execute().use { response ->
                if (!response.isSuccessful) {
                    logger.warn("Error sending SMS {}", response.body?.string())
                    throw IOException("Unexpected code $response")
                logger.info("SMS Status - {}", response.body?.string())
        } catch (e: Exception) {
            logger.warn("Error sending SMS", e)
            throw e


We will use RestTemplate to fetch balance of SMS from 2factor account.

Fetch promotional balance
fun getPromoBalance() {
    val restTemplate= RestTemplate()
    val responseEntity = restTemplate.exchange("http://2factor.in/API/V1/$apiKey/ADDON_SERVICES/BAL/PROMOTIONAL_SMS", HttpMethod.GET, HttpEntity.EMPTY, String::class.java)
    if (responseEntity.statusCode.is2xxSuccessful) {
        val body = responseEntity.body
        logger.info("Promotional SMS Balance is {}", body)

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