Java Technologies - Lab 2

Spring Boot

Compulsory (1p)

• Create a Spring Boot application using spring initializr. Add dependencies for Dev Tools, Spring Web.
• Change the port at which Tomcat runs to 8081.
• Add an endpoint /hello returning a greeting message defined in application.properties.
• Add support for Spring Actuator in pom.xml and test some endpoints.

Homework (2p)

Create a Spring Boot application that must run in multiple environments, such as development, and production.
Each environment uses a different database, and the database connection details are provided in application-{profile}.yml. The application should use JDBC for database access, conditional bean creation with Spring Expression Language (SpEL) and config property injection.

• The host, port, database name, user and password will be specified in the environment.
• Choose between @ConfigurationProperties or @Value in order to read config data and motivate your decision.
• Ensure that the application connects to the correct database automatically based on the active profile by printing some values from a database table; use a CommandLineRunner or ApplicationLineRunner.
• Verify that command-line arguments take precedence over the ones in application.yml.
• Define a scenario where @Profile is used together with @ConditionalOnExpression in order to choose the right database.
• Implement a custom Actuator endpoint or an InfoContributor to return information about the database to which the application is connected.

Advanced (2p)

Create a scenario in which multiple services must share configuration but also adapt to different environments (dev, prod), using Spring Cloud Config.

• A Config Server backed by Git
• Two Config Clients (Service A and Service B)
• Environment-specific profiles
• Runtime refresh for dynamic configuration updates
• Prove that your setup is working (screenshots, server/client logs, etc.)

• Spring Boot Reference Documentation
• YAML: YAML Ain't Markup Language
• Spring Profiles
• JDBC Basics