Spring Applications

Exercise: Hello Application (Configuration Classes)

1. Profiles
   • Rename the existent command-line runner to SimpleRunner and add it to the profile dev
   • Implement another command-line runner InteractiveRunner 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
2. 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
3. Type-safe Properties
   • Implement a configuration 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 into the Greeting service to generate an appropriate daytime greeting

Solution