gaerfield / 2020-01_ktws

Koans for a kotlin-workshop

2020-01_ktws

Koans for a kotlin-workshop

• slides in gaerfield/2018-04-26_Kotlin_jug-gr
• Movie-Database in this project obtained from danielgrijalva/movie-stats
• alternative training-data - 14 Best Movie Datasets for Machine Learning

further self-studying kotlin-links:

• do practice with Kotlin-Koans
• couroutines
• scope-functions (let, with, run, etc ...)
• idiomatic kotlin
• support in spring for kotlin - very important to read
• mixit example-app contains all the hypes: kotlin, spring, reactive-api, mongo, gradle, junit-tests

After succesful start of the app, you can visit:

• database: http://localhost:8080/h2-console
  • user: sa
  • password (keep empty):
  • database: jdbc:h2:mem:testdb
• swagger: http://localhost:8080/swagger-ui.html
• rest-service: http://localhost:8080/least10
• use RestCalls.http to do requests

Exercises

model the following Domain with kotlin

Artist: An individual or group who creates music

• name: The name of the artist (e.g., “The Beatles”)
• members: A set of other artists who comprise this group (e.g., “John Lennon”); this field might be empty
• origin: The primary location of origin of the group (e.g., “Liverpool”).

Track: A single piece of music

• name: The name of the track (e.g., “Yellow Submarine”)

Album A single release of music, comprising several tracks

• name: The name of the album (e.g., “Revolver”)
• tracks: A list of tracks
• musicians: A list of artists who helped create the music on this album

Create some new REST-Services

We have Movie-Database and want to gather some trivial infos. Create some new Services in "MovieService", and collect for example:

• movies group by score (0-1, 1-2, 2-3, etc.) and give a count of movies within this groups
• top 10 studios by number of productions
• directors grouped by number of productions with top 3 by average score, i.e.:

directors with 5 movies:
  Steven Spielberg (avg-score: 5.2), Francis Ford Coppola (avg.-score: 6.1)
directors with 4 movies: ..

• do the previous task with least average score instead
• which persons (actors, writers, directors) have acted in multiple roles for the same or for different movies, i.e.:

Woody Allen:
    Writer: Scoop, Midnight in Paris 
    Actor: Scoop
    Director: Scoop
...