Steps:

1 - Spring Initializr

• Go to https://start.spring.io/
• Change the Artifact to "item-catalog"
• Select: web, acutator, devtools, jpa, h2, cache, lombok
• Click Generate
• Find the download, unzip and move to your workspace/repo folder

2 - Import into IntelliJ

• Select the maven pom.xml and import
• Wait...
• Update the application.properties
  • management.endpoints.web.exposure.include=*
  • management.endpoint.health.show-details=always
  • spring.datasource.platform=h2
  • spring.jpa.show-sql=true
• Select "run" to verify the app is running
• Hit the actuator
  • http :8080/actuator/health

3 - Create a traditional JPA Entity + Repository + Controller

• Create a package "items"
• Create a class Item
  • Add fields id, upc, name, size, lastModified
  • Add Lombok - @Data, @NoArgs, @Entity and @Id (plus strategy Identity)
• Create a class ItemRepository
  • extends JpaRepository<Item, Long>
  • add method Optional getByUpc
• Create a class ItemController
  • add @RestController
  • add @GetRequest accepting UPC (not id)
    • throw custom exception
    • @ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "The resource requested does not exist")
• Add data.sql
• Restart the application
• Test the endpoint
  • http :8080/items/013764027053

4 - Introduce Spring @Cacheable

• Add the @Cacheable annotation to the get method
• Add a println to demonstrate the cache miss
• Restart and test the endpoint
  • Perform a get to show the cash miss
  • Use gfsh to demonstrated that the value is in the region
  • Perform a second get to now show its getting the value from cache