When learning encountered a problem, Springboot Father engineering project which created a sub-project
Then will add a line in the configuration of the parent project
<packaging>pom</packaging>
And then start the parent project, the project found springboot life and death not start up. A variety of debugging, and finally found the problem.
The default springboot use maven project management, packaging and pom file default mode is due to the java program execution.
<packaging>jar</packaging>There is also a war bag and put it into the tomcat execution
<packaging>war</packaging>