cassandra-trainings-crud-template

CRUD application template for Cassandra for Developers training.

Exercise overview

This exercise is meant to practice usage of Datastax' Cassandra Driver for Java, especially it's mapper module. User is is meant to fill in all FixMe gaps with working code.

How to approach the exercise

Ensuring that your machine fulfills requirements

• installed and working Cassandra DB, cqlsh
• sbt
• curl

Preparing database schema

1. Load schema from the create-schema.cql file: cql -f create-schema.cql. It will create a songbrowser keyspace with all necessary contents.
2. Optionally (but recommended), load sample data into the tables by using cql -f insert-data.cql.

Next, run application as-is, without any changes in the source code:

Running application on default port

Run sbt run inside cassandra-crud-rest directory.

Running application on custom port XYZ

Run sbt -Dhttp.port=XYZ run inside cassandra-crud-rest directory.

Running tests (on default port only)

Run sbt test inside inside cassandra-crud-rest directory. Make sure you do not have any application listening on port 9000 (including other Cassandra instances).

Exploring GET endpoints

Try querying following endpoints to see how the application behaves (remember to use appropriate port!). Word beginning with colon (:) should be substituted with a value. Use internet browser as a client:

• http://localhost:9000/albums/:artist - returns all albums for a given artist,
• http://localhost:9000/albums/search/:title - returns all albums which title contains given phrase,
• http://localhost:9000/songs/:artist - returns all songs for a given artist,
• http://localhost:9000/songs/paginate/:artist - returns all songs for a given artist as a paginable list, 1st page only,
• http://localhost:9000/songs/paginate/:artist?page=N - returns all songs for a given artist as a paginable list, Nth page only,
• http://localhost:9000/songs/:release_year/:album_title - returns all songs from the given album (by title and release year).

Exploring POST endpoints:

• http://localhost:9000/album for adding a new album (or updating existing one, remember INSERT / UPDATE operations in Cassandra),
• http://localhost:9000/song for adding or updating a song.

Doing exercise

1. Ensure you know how the application works.
2. Fill in CassandraSupport class to add missing Mappers.
3. Fill in getXYZ and saveXYZ methods in all classes in DAO classes.
4. Take a look at sample tests suite (AlbumsDAOTest).
5. Fill in gaps in SongsByAlbumDAOTest and SongsByArtistDAOTest.

You can verify your results using the tests. For debugging consider using cqlsh or DevCenter tool.