CrudRepository

This defines the structure of the functions for performing create, read, update, and delete operations on the table, including functions exclusively related to geospatial nature:

    /**
      * Basic CRUD operations related to Geospatial
      */
    interface CrudRepository<T, K> {
    /**
      * Creates the table
      */
    fun createTable()

    /**
      * Insert the item
      */
    fun insert(t: T): T

    /**
      * Get list of all the items
      */
    fun findAll(): Iterable<T>

    /**
      * Delete all the items
      */
    fun deleteAll(): Int

    /**
      * Get list of items in the specified box
      */
    fun findByBoundingBox(box: PGbox2d): Iterable<T>

    /**
      * Update the location of the user
      */
    fun updateLocation(userName: K, location: Point)
    }

The MessageRepository handles the actual interaction with the database; in our case, it performs the CRUD operations on the Messages table:

    /**
     * @inheritDoc
     */
    interface MessageRepository: CrudRepository<Message, Int>

    /**
     * @inheritDoc
     */
    @Repository
    @Transactional
    class DefaultMessageRepository : MessageRepository {

      /**
       * @inheritDoc
       */
      override fun createTable() = SchemaUtils.create(Messages)

      /**
       * @inheritDoc
       */
      override fun insert(t: Message): Message {
        t.id = Messages.insert(insertQuery(t))[Messages.id]
        return t
      }

      /**
       * @inheritDoc
       */
      override fun findAll() = Messages.selectAll().map { 
        it.getMessage() }

      /**
       * @inheritDoc
       */
      override fun findByBoundingBox(box: PGbox2d) = Messages.select { 
        Messages.location within box }.map { it.getMessage() }

      /**
       * @inheritDoc
       */
      override fun updateLocation(id:Int, location: Point) {
        location.srid = 4326
        Messages.update({ Messages.id eq id}) { it[Messages.location]  
         = location}
      }

      /**
       * @inheritDoc
       */
      override fun deleteAll() = Messages.deleteAll()

    }

There are lots of advantages of using the Repository pattern. We recommend you read more about it.