In this post, we'll learn how to build a REST API with Spring Boot.
We'll start by creating a new Spring Boot project. Then, we'll add a dependency to our project that will allow us to create a REST API.
Next, we'll create a controller that will handle HTTP requests to our API. Finally, we'll test our API using Postman.
First, we'll need to create a new Spring Boot project. We can do this using the Spring Initializr.
We'll need to specify the following information:
Once we've filled out the form, we can click "Generate Project." This will download a ZIP file containing our project.
Next, we'll need to add a dependency to our project. This dependency will allow us to create a REST API.
We can do this by adding the following to our build.gradle file:
dependencies {
...
compile("org.springframework.boot:spring-boot-starter-web")
}
Now that we have our project set up, we can start creating our API.
We'll start by creating a controller. This controller will handle HTTP requests to our API.
We can do this by creating a new Kotlin file called DemoController.kt in the com.example.demo package.
package com.example.demo
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RestController
@RestController
class DemoController {
@GetMapping("/")
fun index(): String {
return "Hello, world!"
}
}
In this file, we've created a controller with a single endpoint. This endpoint will return the string "Hello, world!" when accessed.
Now that we've created our API, we can test it to make sure it works as expected.
We can do this using Postman. Postman is a tool that allows us to send HTTP requests to our API.
First, we'll need to start our application. We can do this by running the following command:
./gradlew bootRun
Once our application has started, we can send an HTTP GET request to the "/" endpoint. We should see the string "Hello, world!" in the response body.
In this post, we've learned how to build a REST API with Spring Boot. We've created a new project, added a dependency, created a controller, and tested our API.