Swagger

Finally, we can test the application that was developed throughout this section. To achieve this, we will use Swagger — a convenient tool that does not require installation, as it is integrated directly into our application by adding it as a dependency.

You don’t need to manually write out what each of your methods does or the potential responses it can return; Swagger automatically generates all of this based on your code and offers a user-friendly interface.

With Swagger UI, users can visually see how to interact with the API and test requests directly in the browser, simplifying both development and testing.

Real-Life Example

Imagine you have an online store that provides an API for creating orders, adding items to the cart, calculating shipping costs, and processing payments. Developers working for your clients or partners can use this API to integrate their applications with your system.

If the API is well-documented using Swagger, they will easily understand how to call the necessary methods, which parameters to pass, and what responses to expect — without needing to read the source code or ask for clarifications.

Integration with Spring Boot

Integrating Swagger into a Spring Boot project is quite simple and only requires adding a few dependencies and annotations.

The first step is to add the necessary dependencies to your pom.xml file (if you're using Maven).

Configuring Swagger

You can create a configuration class for Swagger if you need to set additional parameters, for example:

SwaggerConfig


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@Configuration
public class SwaggerConfig {

    @Bean
    public GroupedOpenApi publicApi() {
        return GroupedOpenApi.builder()
                .group("spring")
                .pathsToMatch("/**")
                .build();
    }

}

This code configures Swagger for a Spring Boot application using a configuration class annotated with @Configuration, which indicates that this class will be used to configure application components. Inside, a bean is created using the @Bean annotation, allowing Spring to manage its lifecycle.

The bean returns a GroupedOpenApi object, which configures an API group named spring through the group() method. Next, the pathsToMatch("/") method specifies that Swagger should document all available API paths, and the call to build() finalizes the configuration process by creating the object with the specified parameters.

After integrating Swagger into the project, you can access the documentation at:

Summary

Swagger is a powerful tool for documenting REST APIs, making API development, testing, and maintenance much easier.

Its integration with Spring Boot simplifies usage even further, thanks to the automatic generation of documentation and the user-friendly Swagger UI interface for testing APIs.

1. What is the primary purpose of `Swagger`?

2. How do you access the `Swagger UI` after integrating it into a `Spring Boot` project?

¿Todo estuvo claro?

Sección 3. Capítulo 6