Generating Documentation | Spring Rest Docs

Introduction

Spring REST Docs is a tool that helps you generate documentation for your RESTful services. It integrates with Spring's testing framework to produce snippets that can be included in your documentation. This tutorial will guide you through the process of generating documentation from start to finish.

Prerequisites

Before we start generating documentation, ensure you have the following:

A Spring Boot application set up with REST Controllers.
JUnit 5 and Maven/Gradle as your build tool.
Spring REST Docs dependency added to your project.

Setting Up Spring REST Docs

To get started, you need to add the Spring REST Docs dependency to your project. If you are using Maven, add the following to your pom.xml:


                    <dependency>

                      <groupId>>org.springframework.restdocs</groupId>

                      <artifactId>spring-restdocs-mockmvc</artifactId>

                      <version>2.0.6</version>

                    </dependency>

For Gradle, add the following line to your build.gradle:


                    implementation 'org.springframework.restdocs:spring-restdocs-mockmvc:2.0.6'

Writing Tests with Spring REST Docs

Spring REST Docs works by generating snippets during tests. Here’s an example of how to write a test for a REST controller:


                    import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.

                    document;

                    import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.

                    get;

                    import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.

                    status;


                    @SpringBootTest

                    @AutoConfigureMockMvc

                    public class MyControllerTest {

                       @Autowired

                       private MockMvc mockMvc;


                       @Test

                       public void getExample() throws Exception {

                          this.mockMvc.perform(get("/api/example"))

                              .andExpect(status().isOk())

                              .andDo(document("example"));

                       }

                    }

In the example above, we create a test for a REST endpoint that returns an example resource. The document("example") method call generates a snippet for this endpoint.

Generating the Documentation

To generate the documentation, run your tests. The snippets will be generated in the target/generated-snippets directory (for Maven) or build/generated-snippets (for Gradle).

You can customize the generated snippets by configuring the spring.restdocs.outputDir property in your application.properties file:


                    spring.restdocs.outputDir=target/snippets

Including Snippets in Documentation

The generated snippets can be included in your documentation using Asciidoctor or Markdown. Here’s an example of how to include a snippet in an Asciidoctor file:


                    [snip]
                    == Example API{.title}
                    include::target/snippets/example.http[]

This will include the documentation for the example API endpoint.

Conclusion

In this tutorial, you learned how to generate documentation for your RESTful services using Spring REST Docs. By integrating documentation generation into your testing process, you can ensure that your API documentation is always up-to-date and accurate.

Generating Documentation with Spring REST Docs