In recent years, Kotlin has become a popular choice for developing Android applications due to its concise syntax and null-safety features. However, Kotlin is not limited to mobile development and can be used for server-side development as well. In this article, we'll take a look at how Kotlin can be used to develop serverless applications.
Serverless architecture is a way of building applications where the server is abstracted away from the developer. In a serverless application, the developer doesn't need to worry about provisioning or managing servers. Instead, they can focus on building the application logic.
There are many benefits to using serverless architecture, including:
Reduced operational costs: With serverless architecture, you only pay for the resources you use. There's no need to pay for idle resources.
Increased scalability: Serverless applications can automatically scale up or down based on traffic demand.
Improved fault tolerance: Serverless applications are designed to be resilient to failures. If one part of the application fails, the rest of the application can continue to function.
Kotlin is a great choice for developing serverless applications due to its interoperability with Java, its concise syntax, and its support for functional programming.
One of the great things about Kotlin is that it's interoperable with Java. This means that you can use Kotlin to develop applications that run on the JVM, and you can call Java code from Kotlin. This is important for serverless applications because you can use the existing Java ecosystem of libraries and frameworks.
Kotlin's concise syntax means that you can write less code to achieve the same results as Java. This can lead to more readable and maintainable code.
Kotlin supports functional programming, which can be used to write more concise and expressive code. Functional programming is especially well-suited for developing serverless applications because of its focus on pure functions and immutability.
Now that we've looked at some of the reasons why Kotlin is a great choice for serverless development, let's see how we can use Kotlin to build a serverless application.
We'll use the AWS Lambda platform to build our application. AWS Lambda is a serverless platform that allows you to run code without provisioning or managing servers.
First, we need to create a new Kotlin project. We'll use the IntelliJ IDEA IDE for this.
Open IntelliJ IDEA and select Create New Project.
Select Kotlin/JVM from the list of project types and click Next.
Enter a project name and click Finish.
IntelliJ IDEA will create a new Kotlin project with the default directory structure.
Next, we need to add the AWS SDK for Java to our project. The AWS SDK for Java is a library that allows us to interact with AWS services from our Java code.
We can add the AWS SDK for Java to our project using Maven. Maven is a build tool that can be used to manage dependencies.
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.11.585</version>
</dependency>
Now we're ready to write our Lambda function. A Lambda function is a piece of code that can be run in response to an event. In our case, we'll write a Lambda function that is triggered when an HTTP request is made to our application.
import com.amazonaws.services.lambda.runtime.Context
import com.amazonaws.services.lambda.runtime.RequestHandler
class MyLambdaFunction : RequestHandler<Map<String, Any>, String> {
override fun handleRequest(input: Map<String, Any>, context: Context): String {
return "Hello, world!"
}
}
Our Lambda function is now complete. Let's deploy it to AWS.
We can deploy our Lambda function using the AWS Lambda console.
Sign in to the AWS Lambda console.
Click Create function.
Select Author from scratch.
Enter the following information:
Function name: MyLambdaFunction
Runtime: Java 8
Handler: com.example.MyLambdaFunction::handleRequest
Role: Create a new role with basic Lambda permissions
Click Create function.
AWS Lambda will create a new Lambda function with the name you specified.
Click Actions and select Upload a .zip file.
Select the file you created in the previous step and click Upload.
AWS Lambda will upload the file and deploy your Lambda function.
Test your Lambda function by clicking Test and selecting Configure test events.
Click Create new test event and enter the following information:
Event template: Hello World
Event name: TestEvent
Click Create.
AWS Lambda will create a new test event.
Click Test.
If the test is successful, you'll see the following message:
Execution result: succeeded(logs)
Click View logs in CloudWatch to view the logs for your Lambda function.
You should see the following log entry:
START RequestId: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx Version: $LATEST
END RequestId: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
REPORT RequestId: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx Duration: xxx.xx ms Billed Duration: 100 ms Memory Size: 128 MB Max Memory Used: 21 MB
Hello, world!
In this article, we've looked at how Kotlin can be used to develop serverless applications. We've seen how Kotlin's interoperability with Java, concise syntax, and support for functional programming make it a great choice for serverless development. We've also seen how to write a Lambda function in Kotlin and deploy it to AWS.