title: how to use Spring Boot profiles
body: <p>i have <code>application.yml</code>,<code>application-dev.yml</code>and<code>application-dev.yml</code></p>
  
  <ol>
  <li>I'm using the maven command <code>mvn spring-boot:run -Dspring.profiles.active=dev</code> it doesn't work and I can not choose the dev profile using <code>mvn spring-boot:run</code>. How do I choose it?</li>
  <li>The documentation says <code>java -jar XXX.jar --spring.profiles.active=dev</code> works, and I tried <code>-Dspring.profiles.active=dev</code> but it does not work. And in my project, i use <code>java -jar XXX.jar</code> it runs, but if I use <code>java -jar XXX.jar --spring.profiles.active=dev</code> to choose dev profile, console print so many logs and warns that i never see used <code>java -jar XXX.jar</code>,and tell me <code>APPLICATION FAILED TO START</code>  </li>
  </ol>
  
  <p>so how to solve two problems? thanks~</p>