Scala Design Patterns - Second Edition

A code example

Let's have a look at our example from the source point of view. The following code listing shows the factory hierarchy:

trait DatabaseConnectorFactory {  def connect(): SimpleConnection}class MySqlFactory extends DatabaseConnectorFactory {  override def connect(): SimpleConnection = new SimpleMysqlConnection}class PgSqlFactory extends DatabaseConnectorFactory {  override def connect(): SimpleConnection = new SimplePgSqlConnection}

We can then use our factory by passing it to a class, that will call the required methods. Here is an example similar to the one we showed for the factory method design pattern:

class DatabaseClient(connectorFactory: DatabaseConnectorFactory) {  def executeQuery(query: String): Unit = {    val connection ...