Swagger UI integration in Spring Boot - Mini Project: Build & Apply

Swagger UI integration

📖 Scenario: You are building a Spring Boot REST API for a simple product catalog. You want to add Swagger UI to your project so that anyone can easily see and test your API endpoints in a friendly web interface.

🎯 Goal: Integrate Swagger UI into your Spring Boot project so that the API documentation is automatically generated and accessible via a web browser.

📋 What You'll Learn

Add the Swagger dependencies to your project

Create a Swagger configuration class

Configure Swagger to scan your REST controllers

Access the Swagger UI page in the browser

💡 Why This Matters

🌍 Real World

Swagger UI helps developers and testers explore and try out REST APIs easily without writing extra code.

💼 Career

Many companies use Swagger/OpenAPI to document APIs clearly, making this skill valuable for backend and full-stack developers.

1

Add Swagger dependencies

Add the following dependency to your pom.xml file inside the <dependencies> section: <dependency>\n <groupId>io.springfox</groupId>\n <artifactId>springfox-boot-starter</artifactId>\n <version>3.0.0</version>\n</dependency>

Spring Boot

# Add the springfox-boot-starter dependency in pom.xml dependencies section
# Your code here

Need a hint?

Make sure to add the dependency inside the <dependencies> tag in your pom.xml.

2

Create Swagger configuration class

Create a Java class named SwaggerConfig in your project under package com.example.config. Annotate it with @Configuration and @EnableOpenApi. Import these annotations from springfox.documentation.oas.annotations.EnableOpenApi and org.springframework.context.annotation.Configuration.

Spring Boot

    io.springfox
    springfox-boot-starter
    3.0.0


// Create SwaggerConfig class with @Configuration and @EnableOpenApi annotations
// Your code here

Need a hint?

This class enables Swagger OpenAPI support in your Spring Boot app.

3

Configure Swagger Docket bean

Inside the SwaggerConfig class, add a public method named api that returns a Docket object. Annotate it with @Bean. In the method, return a new Docket with DocumentationType.OAS_30, and configure it to select any APIs and any paths using select(), apis(RequestHandlerSelectors.any()), and paths(PathSelectors.any()). Import necessary classes from springfox.documentation.spring.web.plugins.Docket, springfox.documentation.spi.DocumentationType, springfox.documentation.builders.PathSelectors, and springfox.documentation.builders.RequestHandlerSelectors.

Spring Boot

    io.springfox
    springfox-boot-starter
    3.0.0


package com.example.config;

import org.springframework.context.annotation.Configuration;
import springfox.documentation.oas.annotations.EnableOpenApi;

@Configuration
@EnableOpenApi
public class SwaggerConfig {

    // Add a @Bean method named api that returns a Docket configured for OAS_30
    // Your code here
}

Need a hint?

This method tells Swagger to document all API endpoints in your project.

4

Access Swagger UI in browser

Run your Spring Boot application. Open a web browser and go to http://localhost:8080/swagger-ui/index.html to see the Swagger UI page with your API documentation.

Spring Boot

    io.springfox
    springfox-boot-starter
    3.0.0


package com.example.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.oas.annotations.EnableOpenApi;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;

@Configuration
@EnableOpenApi
public class SwaggerConfig {

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.OAS_30)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

// Run the application and open http://localhost:8080/swagger-ui/index.html in your browser
# Your code here

Need a hint?

Make sure your Spring Boot app is running on port 8080 (default) before opening the URL.