If you would like to stay in spring boot space just set the pom packaging to jar
<packaging>jar</packaging>
and add the spring-boot-maven-plugin to you build properties in the pom.xml file:
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
then a simple mvn package command will create a complete executable jar file.
See the very good spring reference doc for more details (doing it gradle style also)
spring reference doc