Play Framework 1.x C3PO Database pool configurator

DatabasePoolConfigurator.scala

import play.{configuration, Logger}
import com.mchange.v2.c3p0.ComboPooledDataSource

/**
 * @author Jay Taylor [@jtaylor]
 *
 * @date 2012-03-22
 *
 * @description c3po Database connection pool configuration container and applicator.
 *
 * Example configuration details to add to 'conf/application.conf':
 *
 *      # Database Pool Configuration
 *      # ~~~~~
 *      #
 *      db.pool.driverClass=com.mysql.jdbc.Driver
 *      db.pool.url=jdbc:mysql://localhost/myApp?sessionVariables=storage_engine=InnoDB,character_set_server=utf8&zeroDateTimeBehavior=convertToNull&autoReconnect=true
 *      %stage.db.pool.url=jdbc:mysql://staging/myApp?sessionVariables=storage_engine=InnoDB,character_set_server=utf8&zeroDateTimeBehavior=convertToNull&autoReconnect=true
 *      %prod.db.pool.url=jdbc:mysql://localhost/myApp?sessionVariables=storage_engine=InnoDB,character_set_server=utf8&zeroDateTimeBehavior=convertToNull&autoReconnect=true
 *      db.pool.username=root
 *      db.pool.password=
 *      %stage.db.pool.username=root
 *      %stage.db.pool.password=
 *
 *      # NB: MySQL configuration for testing.
 *      # It's unfortunate that as of Play 1.2.3, whenever you run "play test" or
 *      # "play auto-test", you are automatically running with environment id "test".
 *      # That's a shame, because it means that any workspace in which you want to run·
 *      # tests has to access the database (and anything else) with the same
 *      # configuration. I.e. hostnames, userids, etc.  For the moment, we'll live with
 *      # it.·
 *      #·
 *      %test.db.pool.url=jdbc:mysql://staging/myAppTest?sessionVariables=storage_engine=InnoDB,character_set_server=utf8&zeroDateTimeBehavior=convertToNull&autoReconnect=true
 *
 *      # c3po Database Connection Pooling configuration
 *      # See http://www.mchange.com/projects/c3p0/index.html for more details.
 *      db.pool.initialSize=2
 *      db.pool.minSize=2
 *      db.pool.maxSize=10
 *      db.pool.acquireIncrement=2
 *      %prod.db.pool.initialSize=25
 *      %prod.db.pool.minSize=10
 *      %prod.db.pool.maxSize=100
 *
 *      # in seconds
 *      db.pool.idleConnectionTestPeriod=30
 *      db.pool.maxIdleTime=45
 *      db.pool.maxIdleTimeExcessConnections=60
 *      db.pool.maxConnectionAge=55
 *
 *      # Retry forever
 *      db.pool.acquireRetryAttempts=0
 *
 *      db.pool.testTableName=c3poTestTable
 *      db.pool.preferredTestQuery=SELECT 1
 *      db.pool.testConnectionOnCheckout=true
 *      db.pool.testConnectionOnCheckin=true
 *
 * Example class usage:
 *
 *      val pool = DatabasePoolConfigurator("db.pool")(new ComboPooledDataSource)
 */ 
case class DatabasePoolConfigurator(prefix: String) {

    val driverClass: String                 = configuration(prefix + ".driverClass",                    "com.mysql.jdbc.Driver")
    val username: String                    = configuration(prefix + ".username",                       "root")
    val password: String                    = configuration(prefix + ".password",                       "")
    val jdbcUrl: String                     = configuration(prefix + ".url",                            "jdbc:mysql://localhost/myApp?sessionVariables=storage_engine=InnoDB,character_set_server=utf8&zeroDateTimeBehavior=convertToNull&autoReconnect=true")

    val initialPoolSize: Int                = configuration(prefix + ".initialSize",                    "25").toInt
    val minPoolSize: Int                    = configuration(prefix + ".minSize",                        "25").toInt
    val maxPoolSize: Int                    = configuration(prefix + ".maxSize",                        "100").toInt
    val acquireIncrement: Int               = configuration(prefix + ".acquireIncrement",               "3").toInt

    val idleConnectionTestPeriod: Int       = configuration(prefix + ".idleConnectionTestPeriod",       "30").toInt
    val maxIdleTime: Int                    = configuration(prefix + ".maxIdleTime",                    "0").toInt
    val maxIdleTimeExcessConnections: Int   = configuration(prefix + ".maxIdleTimeExcessConnections",   "0").toInt
    val maxConnectionAge: Int               = configuration(prefix + ".maxConnectionAge",               "0").toInt
    val acquireRetryAttempts: Int           = configuration(prefix + ".acquireRetryAttempts",           "30").toInt

    val automaticTestTable: String          = configuration(prefix + ".testTableName",                  "c3poTestTable")
    val preferredTestQuery: String          = configuration(prefix + ".preferredTestQuery",             "SELECT 1")
    val testConnectionOnCheckin: Boolean    = configuration(prefix + ".testConnectionOnCheckin",        "false").toBoolean
    val testConnectionOnCheckout: Boolean   = configuration(prefix + ".testConnectionOnCheckout",       "true").toBoolean

    /**
     * Applies this c3po configuration to a pooled data source.
     */
    def apply(pool: ComboPooledDataSource): ComboPooledDataSource = {
        Logger info "Applying the following configuration:\n" + this.toString

        pool setDriverClass driverClass
        pool setUser username
        pool setPassword password
        pool setJdbcUrl jdbcUrl

        pool setInitialPoolSize initialPoolSize
        pool setMinPoolSize minPoolSize
        pool setMaxPoolSize maxPoolSize
        pool setAcquireIncrement acquireIncrement

        pool setIdleConnectionTestPeriod idleConnectionTestPeriod
        pool setMaxIdleTime maxIdleTime
        pool setMaxIdleTimeExcessConnections maxIdleTimeExcessConnections
        pool setMaxConnectionAge maxConnectionAge
        pool setAcquireRetryAttempts acquireRetryAttempts

        pool setAutomaticTestTable automaticTestTable
        pool setPreferredTestQuery preferredTestQuery
        pool setTestConnectionOnCheckin testConnectionOnCheckin
        pool setTestConnectionOnCheckout testConnectionOnCheckout

        pool
    }
    
    override val toString: String =
        """DatabasePoolConfiguration(prefix = "%s") ⇒ {
    driverClass                     : """ + driverClass + """
    username                        : """ + username + """
    password                        : """ + password + """
    jdbcUrl                         : """ + jdbcUrl + """
    initialPoolSize                 : """ + initialPoolSize + """
    minPoolSize                     : """ + minPoolSize + """
    maxPoolSize                     : """ + maxPoolSize + """
    acquireIncrement                : """ + acquireIncrement + """
    idleConnectionTestPeriod        : """ + idleConnectionTestPeriod + """
    maxIdleTime                     : """ + maxIdleTime + """
    maxIdleTimeExcessConnections    : """ + maxIdleTimeExcessConnections + """
    maxConnectionAge                : """ + maxConnectionAge + """
    acquireRetryAttempts            : """ + acquireRetryAttempts + """
    automaticTestTable              : """ + automaticTestTable + """
    preferredTestQuery              : """ + preferredTestQuery + """
    testConnectionOnCheckin         : """ + testConnectionOnCheckin + """
    testConnectionOnCheckout        : """ + testConnectionOnCheckout + "\n}"
}