java-tutorials/lagom/README.md

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Steps to setup from scratch

  1. Create sbt build file "build.sbt"

  2. Create plugins file project/plugins.sbt

  3. Create build properties file project/build.properties

  4. Run sbt command from project root to generate project directories, generated projects at target/lagom-dynamic-projects Service Locator project: lagom-internal-meta-project-service-locator cassandra project: lagom-internal-meta-project-cassandra

  5. Create folders in all projects to follow maven like directory structure layout for project source code: src/main/java and src/main/java/resources and test folders.

  6. Weather microservice a) WeatherService Interface with method: weatherStatsForToday() b) WeatherServiceImpl to return weatherstats from a random list of weather stats

  7. Greeting Microservice GreetingService Interface: handleGreetFrom(String user)

    a) Reply back to user with greeting message("Hello") along with weather stats fetched from weather microservice b) Update the greeting message("Hello Again") for an existing user.

  8. GreetingEntity: PersistentEntity<GreetingCommand, GreetingEvent, GreetingState> a) handles ReceivedGreetingCommand b) Stores ReceivedGreetingEvent events to cassandra c) Processes ReceivedGreetingEvent to update GreetingState("Hello" to "Hello Again") if required.

  9. Register modules with lagom using application.conf files.

  10. Run project: sbt lagom:runAll

Sample Run: curl http://localhost:9000/api/greeting/Nikhil; Hello Nikhil! Today's weather stats: Going to be very humid, Take Water

curl http://localhost:9000/api/greeting/Nikhil; Hello Again Nikhil! Today's weather stats: Going to Rain, Take Umbrella