title: Spring boot after https: The Tomcat connector configured to listen on port 8444 failed to start.
body: <p>I followed a guide to enable https in Spring Boot. The application was beforehand working on <a href="https://localhost:8080" rel="noreferrer">https://localhost:8080</a></p>
  
  <p>I've created a <code>keystore.jks</code> which is in the same directory as my <code>application.properties</code>, which now looks like:</p>
  
  <pre><code># Define a custom port instead of the default 8080
  server.port = 8444
  # Tell Spring Security (if used) to require requests over HTTPS
  security.require-ssl=true
  # The format used for the keystore
  server.ssl.key-store-type:PKCS12
  # The path to the keystore containing the certificate
  server.ssl.key-store=keystore.p12
  # The password used to generate the certificate
  server.ssl.key-store-password=&lt;somepassword&gt;
  # The alias mapped to the certificate
  server.ssl.key-alias=tomcat
  </code></pre>
  
  <p>Now, if I run the main method to start the spring boot app, it throws:</p>
  
  <pre><code>Description:
  
  The Tomcat connector configured to listen on port 8444 failed to start. The port may already be in use or the connector may be misconfigured.
  
  Action:
  
  Verify the connector's configuration, identify and stop any process that's listening on port 8444, or configure this application to listen on another port.
  </code></pre>
  
  <p>The port isn't in use, so it must be misconfiguration?</p>
  
  <p>I'm unsure of what to change. It's a simple SPA app, Spring just serves an index.html and has a single REST endpoint. How should tomcat/spring be configured to accept https in this case, and start up without errors?</p>