Spring Boot with Swagger

OpenAPI is a specification for designing and documenting APIs, providing developers with a standardized way to create RESTful services. In this tutorial, we will explore how to integrate OpenAPI into a Spring Boot project using the Springdoc library. Springdoc offers an easy-to-use and powerful solution for generating OpenAPI documentation. By following the steps outlined below, you’ll be able to implement OpenAPI in your Spring Boot project quickly and efficiently.

To follow along with this tutorial, you should have a basic understanding of Kotlin, Spring Boot, and RESTful APIs. Ensure that you have a Spring Boot project set up and ready to work with.

Step 1: Add Dependencies
Open your project’s pom.xml file and add the following dependencies to integrate Springdoc into your Spring Boot project:


Replace {latest-version} with the most recent version of Springdoc available at the time of implementation.

Step 2: Configuration
Springdoc requires minimal configuration to enable OpenAPI documentation generation in your Spring Boot application. By default, it automatically detects your RESTful controllers and generates documentation based on their annotations.

Step 3: API Documentation
Annotate your RESTful controllers with the appropriate OpenAPI annotations provided by Springdoc to generate detailed API documentation. For example, let’s consider a UserController class:

import io.swagger.v3.oas.annotations.Operation
import io.swagger.v3.oas.annotations.tags.Tag
import org.springframework.web.bind.annotation.*

@Tag(name = "User Management")
class UserController {

    @Operation(summary = "Get all users")
    fun getAllUsers(): List<UserResponse> {
        // Implementation

    @Operation(summary = "Create a new user")
    fun createUser(@RequestBody user: UserParam) {
        // Implementation

    // Additional methods

In this example, we have used Springdoc’s @Tag and @Operation annotations to provide meaningful descriptions for the API endpoints.

Step 4: Test the API Documentation
Start your Spring Boot application, and open a web browser. Access the following URL: http://localhost:8080/swagger-ui.html.

Springdoc will automatically generate an interactive API documentation page using the OpenAPI specification. You can explore the endpoints, view their descriptions, and even test them directly from the Swagger UI.

Step 5: Customizing Documentation
Springdoc offers numerous additional annotations and options to customize your API documentation further. You can document request parameters, response models, authentication mechanisms, and more using Springdoc’s annotations. Refer to the Springdoc documentation for a complete list of available annotations and their usage.

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