Spring Core

Exercise: Hello Application (Configuration)

1. Configuration Class
   • Remove the TestRunner class
   • Instead create the command line runner in a bean method of a configuration class RunnerConfig
2. Profiles
   • Add the existing command line runner to the profile dev
   • Create another runner that asks the user for his name and age, and add it to the profile prod
   • Run the application using the spring.profiles.active command line option
3. External Properties
   • Write a configuration file application.properties that contains a property for the adult age
   • Inject the property value into the Hello service to decide which message to return
   • Use a command line option to override the property value
4. Type-safe Properties
   • Implement a configuration properties class TimesOfDay with properties for the times of day
   • Add the spring-boot-starter-validation starter and use annotations to validate the properties
   • Inject an instance of it into the Greeting service to generate an appropriate daytime greeting