SessionWrapper.scala

  abstract class SessionWrapper(_session: => Session) extends Session {
    lazy val session = _session
 
    def conn: Connection = session.conn
    def metaData = session.metaData
    def capabilities = session.capabilities
    override def resultSetType = session.resultSetType
    override def resultSetConcurrency = session.resultSetConcurrency
    override def resultSetHoldability = session.resultSetHoldability
    def close() { throw new UnsupportedOperationException }
    def rollback() { session.rollback() }
    def withTransaction[T](f: => T): T = session.withTransaction(f)
 
    private val statementCache = new mutable.HashMap[String, PreparedStatement]
    def getPreparedStatement(statement: String): PreparedStatement =
      statementCache.getOrElseUpdate(statement, this.conn.prepareStatement(statement))
 
    override def forParameters(rsType: ResultSetType = resultSetType, rsConcurrency: ResultSetConcurrency = resultSetConcurrency,
      rsHoldability: ResultSetHoldability = resultSetHoldability) = throw new UnsupportedOperationException
  }
 
  abstract class RSession(roSession: => Session) extends SessionWrapper(roSession)
  class ROSession(roSession: => Session) extends RSession(roSession)
  class RWSession(rwSession: Session) extends RSession(rwSession)
 
  implicit def roToSession(roSession: ROSession): Session = roSession.session
  implicit def rwToSession(rwSession: RWSession): Session = rwSession.session