title: spring boot with vaadin takes several minutes to start
body: <p>I know there have been a few posts about it and i tried a few solutions which seemed to have improved the situation a bit, but I still experience an extraordinarily long start-up on my machine.</p>
  <p>I use spring-boot 2.4.4 and vaadin 14.3.9 for my frontend developing in STS 4.10 on Windows 10. I compile using Java 11.
  Having debug enabled in my properties I can see a huge gap of around 5 minutes between &quot;Mapping servlets&quot; and &quot;Starting Frontend compilation&quot;</p>
  <pre><code>11:54:30.236 [restartedMain] INFO  o.s.b.w.e.tomcat.TomcatWebServer - Tomcat initialized with port(s): 8080 (http)
  11:54:31.171 [restartedMain] DEBUG o.s.b.w.s.c.ServletWebServerApplicationContext - Published root WebApplicationContext as ServletContext attribute with name [org.springframework.web.context.WebApplicationContext.ROOT]
  11:54:31.172 [restartedMain] INFO  o.s.b.w.s.c.ServletWebServerApplicationContext - Root WebApplicationContext: initialization completed in 6870 ms
  11:54:52.463 [restartedMain] DEBUG o.s.b.w.s.ServletContextInitializerBeans - Mapping filters: filterRegistrationBean urls=[/*] order=-2147483647, springSecurityFilterChain urls=[/*] order=-100, characterEncodingFilter urls=[/*] order=-2147483648, formContentFilter urls=[/*] order=-9900, requestContextFilter urls=[/*] order=-105, cacheCleanupFilter urls=[/*] order=2147483647, getBasicAuthFilter urls=[/*] order=2147483647, getFormAuthFilter urls=[/*] order=2147483647, loggingFilter urls=[/*] order=2147483647
  11:54:52.464 [restartedMain] DEBUG o.s.b.w.s.ServletContextInitializerBeans - Mapping servlets: dispatcherServlet urls=[/], springServlet urls=[/vaadinServlet/*]
  [38;5;35m
  ------------------ Starting Frontend compilation. ------------------
  [0m[94mVaadin application has been deployed and started to the context path &quot;/&quot;.
  [0m11:59:07.893 [restartedMain] DEBUG o.s.b.a.m.w.s.WebMvcMetricsFilter - Filter 'webMvcMetricsFilter' configured for use
  </code></pre>
  <p>so I have no clue what happens in between. I suppose it could be vaadin doing some of its magic, but I cannot be certain.</p>
  <p>I'd love to paste the output for the auto configuration here but unfortunately this would make me exceed the 30k characters limit (Body is limited to 30000 characters; you entered 122954). Is there a better way to paste it or are there certain parts of it that might be of value for you?</p>
  <p>In my application properties (yml) I also whitelisted my views package for vaadin and in my windows hosts file I uncommented the localhost resolution lines, but I'm not certain if that has any influence</p>
  <pre><code>vaadin:
    whitelisted-packages:
    - xx/path/to/view
  </code></pre>
  <p>In addition I just upgraded to the newest STS version (see above), and created a new workspace just to make sure this wasn't the reason.</p>
  <p>Not sure where to start looking and how to find out what's exactly happening in those 5 minutes. Maybe you can help me find a solution. thanks in advance</p>