In the spring-boot module, you can find two classes to create files that are often useful for process monitoring:
ApplicationPidFileWriter creates a file containing the application PID (by default, in the application directory with a file name of application.pid).WebServerPortFileWriter creates a file (or files) containing the ports of the running web server (by default, in the application directory with a file name of application.port).By default, these writers are not activated, but you can enable:
In the META-INF/spring.factories file, you can activate the listener(s) that writes a PID file, as shown in the following example:
org.springframework.context.ApplicationListener=\ org.springframework.boot.context.ApplicationPidFileWriter,\ org.springframework.boot.web.context.WebServerPortFileWriter