spring-boot-mongodb-jwt: Unable to find a suitable main class, please add a 'mainClass' property -> [Help 1]

[watcharinc]

ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.4.0.RELEASE:run (default-cli) on project spring-boot-mongodb-jwt: Unable to find a suitable main class, please add a 'mainClass' property -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException