How to generate this Spring-boot API documentation example? - spring-boot

Question

I'm trying to track down how some Java Spring-boot API was generated by a developer who has since left the company. The document looks like this:
We have swagger, but this doesn't look like anything generated from that. Definitely doesn't look like javadoc. Any ideas?
Thanks to the answer by João Dias, I found this in pom.xml:
<!-- Run the generated asciidoc through Asciidoctor to generate other
documentation types, such as PDFs or HTML5 -->
<plugin>
<groupId>org.asciidoctor</groupId>
<artifactId>asciidoctor-maven-plugin</artifactId>
<version>1.5.6</version>
<!-- Include Asciidoctor PDF for pdf generation -->
<dependencies>
<dependency>
<groupId>org.asciidoctor</groupId>
<artifactId>asciidoctorj-pdf</artifactId>
<version>1.5.0-alpha.16</version>
</dependency>
<dependency>
<groupId>org.jruby</groupId>
<artifactId>jruby-complete</artifactId>
<version>1.7.21</version>
</dependency>
</dependencies>
<!-- Configure generic document generation settings -->
<configuration>
<sourceDirectory>${asciidoctor.input.directory}</sourceDirectory>
<sourceDocumentName>index.adoc</sourceDocumentName>
<attributes>
<doctype>book</doctype>
<toc>left</toc>
<toclevels>3</toclevels>
<numbered></numbered>
<hardbreaks></hardbreaks>
<sectlinks></sectlinks>
<sectanchors></sectanchors>
<generated>${generated.asciidoc.directory}</generated>
</attributes>
</configuration>
<!-- Since each execution can only handle one backend, run separate executions
for each desired output type -->
<executions>
<execution>
<id>output-html</id>
<phase>test</phase>
<goals>
<goal>process-asciidoc</goal>
</goals>
<configuration>
<backend>html5</backend>
<outputDirectory>${asciidoctor.html.output.directory}</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>

Answer 1

If I am not mistaken this is Spring REST Docs. For more details:
https://docs.spring.io/spring-restdocs/docs/current/reference/html5/
https://www.baeldung.com/spring-rest-docs