title: Why does Spring boot not support jsp while it can render the page if we add proper jar reference
body: <p>It is written everywhere that Spring boot does not support jsp view. In its official document there are three reasons</p>
  
  <blockquote>
    <ul>
    <li>With Jetty and Tomcat, it should work if you use war packaging. An executable war will work when launched with java -jar, and will also
    be deployable to any standard container. JSPs are not supported when
    using an executable jar.</li>
    <li>Undertow does not support JSPs.</li>
    <li>Creating a custom error.jsp page does not override the default view for error handling. Custom error pages should be used instead.</li>
    </ul>
  </blockquote>
  
  <p>For the first item, 'JSPs are not supported when using an executable jar'. But when I add reference to tomcat-embed-jasper and set correct resource path in application.properties, the jsp file can also be rendered well.</p>
  
  <p>I guess this may mean that Spring boot not support jsp without invovling other reference libs such as tomcat-embed-jasper.</p>
  
  <p>But for thymleaf, we also have to import spring-boot-starter-thymeleaf. Why can we say that Spring boot support thymleaf with involving extra libs.</p>
  
  <p>So how can I understand the first item in document? </p>