title: What is the function of springdoc-openapi-maven-plugin configuration/apiDocsUrl?
body: <p>I'm running the springdoc-openapi-maven-plugin, with the following (standard) configuration:</p>
  
  <pre><code>        &lt;plugin&gt;
              &lt;groupId&gt;org.springdoc&lt;/groupId&gt;
              &lt;artifactId&gt;springdoc-openapi-maven-plugin&lt;/artifactId&gt;
              &lt;version&gt;0.2&lt;/version&gt;
              &lt;executions&gt;
                  &lt;execution&gt;
                      &lt;id&gt;integration-test&lt;/id&gt;
                      &lt;goals&gt;
                          &lt;goal&gt;generate&lt;/goal&gt;
                      &lt;/goals&gt;
                  &lt;/execution&gt;
              &lt;/executions&gt;
          &lt;/plugin&gt;
  </code></pre>
  
  <p>The plugin appears to run, but there is no output.</p>
  
  <p>I am getting a 404 error in the Maven output:</p>
  
  <pre><code>[INFO] --- springdoc-openapi-maven-plugin:0.2:generate (integration-test) @ paatinc-util-websrv ---
  10:40:33.930 [http-nio-8080-exec-1] INFO  o.a.c.c.C.[Tomcat].[localhost].[/] - Initializing Spring DispatcherServlet 'dispatcherServlet'
  10:40:33.931 [http-nio-8080-exec-1] INFO  o.s.web.servlet.DispatcherServlet - Initializing Servlet 'dispatcherServlet'
  10:40:33.956 [http-nio-8080-exec-1] INFO  o.s.web.servlet.DispatcherServlet - Completed initialization in 25 ms
  10:40:33.969 [http-nio-8080-exec-1] INFO  io.paat.util.filter.LoggingFilter - GET http://localhost:8080/v3/api-docs from 127.0.0.1
  [ERROR] An error has occured: Response code 404
  </code></pre>
  
  <p>I can see from my log that the 404 is on a call to: <a href="http://localhost:8080/v3/api-docs" rel="noreferrer">http://localhost:8080/v3/api-docs</a></p>
  
  <p>I also see in the springdoc-openapi-maven-plugin docs the following configuration:</p>
  
  <pre><code> &lt;configuration&gt;
    &lt;apiDocsUrl&gt;http://localhost:8080/v3/api-docs&lt;/apiDocsUrl&gt;
    &lt;outputFileName&gt;openapi.json&lt;/outputFileName&gt;
    &lt;outputDir&gt;/home/springdoc/maven-output&lt;/outputDir&gt;
   &lt;/configuration&gt;
  </code></pre>
  
  <p>So, it appears that the plugin is attempting to open the local server during integration tests and is failing. What is the point of this? I thought that the plugin would read though my source files and generate an openapi.json file. Why does it need to make an HTTP connection to /v3/api-docs?</p>