Receive an SMS Message with Java

Handle and reply to incoming SMS Messages to your Sinch number.

Learn how to quickly set up a Java server to receive SMS messages with the Sinch API using the Spark web application framework.

Set up your Java application

1. Create a new folder where you want to store your application. Open a command prompt or terminal to that location and execute the following command:
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   gradle init

   This command starts up the process to create a new blank Java application. You can select the default options for most of the prompts, but ensure you select that you want to create an application.

   Note:

   This guide assumes you're using Gradle but if you want to use another Java build tool, we've provided installation instructions for the most popular ones below.

2. To listen to incoming HTTP requests, we will use Spark. In your build.gradle file add the following dependencies:
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   dependencies {
       implementation: 'com.sparkjava:spark-core:2.9.4'
       implementation: 'org.slf4j:slf4j-simple:2.0.9'
   }

Now that you've set up your application file, you must install the SDK itself and populate the code sample with your corresponding information.

The easiest way to install the SDK is using the Maven central repository.

Installing the SDK

You can create your Java project using your favorite method. Once your project is created, you need to add the SDK as a dependency. Depending on if you are using Gradle or Maven, you can add the necessary dependencies in the following ways:

Gradle

...
repositories {
    ...
    mavenCentral()
    ...
}
...

dependencies {
    ...
    implementation 'com.sinch.sdk:sinch-sdk-java:+'
    ...
}
...

...
repositories {
    ...
    mavenLocal()
    ...
}
...

dependencies {
    ...
    implementation("com.sinch.sdk:sinch-sdk-java:+")
    ...
}
...

Maven

<dependency>
    <groupId>com.sinch.sdk</groupId>
    <artifactId>sinch-sdk-java</artifactId>
    <version>LATEST</version>
</dependency>

Modify your application

The code provided in App.java includes placeholder parameters. You'll need to update the parameters detailed in the following subsections with your values.

Initialize the client

Before initializing a client using this SDK, you'll need three pieces of information:

• Your Project ID
• An access key ID
• An access key Secret

To start using the SDK, you need to initialize the main client class and create a configuration object to connect to your Sinch account. You can find all of the credentials you need on your Sinch dashboard.

import com.sinch.sdk.SinchClient;
import com.sinch.sdk.models.Configuration;
import com.sinch.sdk.models.SMSRegion;

public class App {
    
    public static void main(String[] args) {
        SinchClient client = new SinchClient(Configuration.builder()
                                    .setKeyId("YOUR_access_key")
                                    .setKeySecret("YOUR_access_secret")
                                    .setProjectId("YOUR_project_id")
                                    .setSmsRegion(SMSRegion.US)
                                    .build());
    }
}

import com.sinch.sdk.SinchClient;
import com.sinch.sdk.models.Configuration;
import com.sinch.sdk.models.SMSRegion;

public class App {
    
    public static void main(String[] args) {
        SinchClient client = new SinchClient(Configuration.builder()
                                    .setKeyId("YOUR_access_key")
                                    .setKeySecret("YOUR_access_secret")
                                    .setProjectId("YOUR_project_id")
                                    .setSmsRegion(SMSRegion.EU)
                                    .build());
    }
}

Set up an ngrok tunnel and run your application

1. In the terminal or command prompt window, start running your application with:
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   gradle run

2. Before you can handle incoming traffic to your local server, open up a tunnel to your local server. For that, you can use an ngrok tunnel. If you haven't already, install ngrok, and then open a terminal or command prompt. Run the following command:
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   ngrok http 4567

   Take note of the URL that ends in .ngrok.io.

Configure your Callback URL

Send your SMS message

Now send an SMS message to your Sinch number from your mobile phone and you will get an automatic reply.

Next Steps

• Explore the API specification to test more endpoints.