External application properties file configuration in Spring Boot

This video will given in detail idea on how to configure external application properties file in Spring Boot application which is deployed in external tomcat server.

Refer below GitHub link for source code:

Timestamp:
00:00 Introduction
00:22 Why externalize configuration files
03:41 Project Summary
04:31 Implementation summary
05:49 First step
06:46 Second Step
08:27 Build, deploy and validate code
10:43 Practical to present benefit of externalizing config

[princekumarmaurya]

after deleting properties file i am getting error while making war file why

[ukarsaja]

if we change one of the properties in the file while the application is running, does the application need to be restarted so that the application runs with the new property?