SDP（2）：ScalikeJDBC-Connection Pool Configuration

  scalikeJDBC可以通过配置文件来设置连接池及全局系统参数。对配置文件的解析是通过TypesafeConfig工具库实现的。默认加载classpath下的application.conf,application.json和application.properties文件。作为尝试，我们可以在resource/application.conf文件里进行h2和mysql数据库的JDBC驱动参数定义：

# JDBC settings
db {
  h2 {
    driver="org.h2.Driver"
    url="jdbc:h2:tcp://localhost/~/slickdemo"
    user=""
    password=""
    poolInitialSize=5
    poolMaxSize=7
    poolConnectionTimeoutMillis=1000
    poolValidationQuery="select 1 as one"
    poolFactoryName="commons-dbcp"
  }
}

db.mysql.driver="com.mysql.jdbc.Driver"
db.mysql.url="jdbc:mysql://localhost:3306/testdb"
db.mysql.user="root"
db.mysql.password="123"
db.mysql.poolInitialSize=5
db.mysql.poolMaxSize=7
db.mysql.poolConnectionTimeoutMillis=1000
db.mysql.poolValidationQuery="select 1 as one"
db.mysql.poolFactoryName="commons-dbcp"

# scallikejdbc Global settings
scalikejdbc.global.loggingSQLAndTime.enabled=true
scalikejdbc.global.loggingSQLAndTime.logLevel=info
scalikejdbc.global.loggingSQLAndTime.warningEnabled=true
scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis=1000
scalikejdbc.global.loggingSQLAndTime.warningLogLevel=warn
scalikejdbc.global.loggingSQLAndTime.singleLineMode=false
scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace=false
scalikejdbc.global.loggingSQLAndTime.stackTraceDepth=10

上面h2和mysql设置采用了不同的格式。scalikeJDBC是在trait DBs中的setup(dbname)来进行dbname数据库连接池的设定的：

/**
 * DB configurator
 */
trait DBs { self: TypesafeConfigReader with TypesafeConfig with EnvPrefix =>

  def setup(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    val JDBCSettings(url, user, password, driver) = readJDBCSettings(dbName)
    val cpSettings = readConnectionPoolSettings(dbName)
    if (driver != null && driver.trim.nonEmpty) {
      Class.forName(driver)
    }
    ConnectionPool.add(dbName, url, user, password, cpSettings)
  }

  def setupAll(): Unit = {
    loadGlobalSettings()
    dbNames.foreach { dbName => setup(Symbol(dbName)) }
  }

  def close(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    ConnectionPool.close(dbName)
  }

  def closeAll(): Unit = {
    ConnectionPool.closeAll
  }

}

/**
 * Default DB setup executor
 */
object DBs extends DBs
  with TypesafeConfigReader
  with StandardTypesafeConfig
  with NoEnvPrefix

可以看到：setup(dbname)进行了dbname设置操作包括Class.forName(driver),ConnectionPool.add(dbname...)。我们首先试试使用h2数据库进行一些操作：

import scalikejdbc._
import scalikejdbc.config._
import org.joda.time._
import scala.util._   //Try
import scalikejdbc.TxBoundary.Try._

object JDBCConfig extends App{
  // DBs.setup/DBs.setupAll loads specified JDBC driver classes.
  // DBs.setupAll()
   DBs.setup('h2)
   DBs.setup('mysql)
  // Unlike DBs.setupAll(), DBs.setup() doesn't load configurations under global settings automatically
  DBs.loadGlobalSettings()

  val dbname = 'h2

  //clear table object
  try {
    sql"""
        drop table members
          """.execute().apply()(NamedAutoSession(dbname))
  }
  catch {
    case _: Throwable =>
  }

也可以用DBs.setupAll()来设定配置文件中的所有数据库设置。setupAll()还运行了loadGlobalSettings()。下面我们再进行实际的数据操作：

 //construct SQL object
  val createSQL: SQL[Nothing,NoExtractor] =SQL("""
    create table members (
      id bigint primary key auto_increment,
      name varchar(30) not null,
      description varchar(1000),
      birthday date,
      created_at timestamp not null
    )""")

  //run this SQL
  createSQL.execute().apply()(NamedAutoSession(dbname))   //autoCommit

  //data model
  case class Member(
                     id: Long,
                     name: String,
                     description: Option[String] = None,
                     birthday: Option[LocalDate] = None,
                     createdAt: DateTime)

  def create(name: String, birthday: Option[LocalDate], remarks: Option[String])(implicit session: DBSession): Member = {
    val insertSQL: SQL[Nothing,NoExtractor]  =
      sql"""insert into members (name, birthday, description, created_at)
           values (${name}, ${birthday}, ${remarks}, ${DateTime.now})"""
    val id: Long = insertSQL.updateAndReturnGeneratedKey.apply()
    Member(id, name, remarks, birthday,DateTime.now)
  }

  val users = List(
    ("John",new LocalDate("2008-03-01"),"youngest user"),
    ("Susan",new LocalDate("2000-11-03"),"middle aged user"),
    ("Peter",new LocalDate("1983-01-21"),"oldest user"),
  )

  val result: Try[List[Member]] =
    NamedDB(dbname) localTx { implicit session =>
      Try {
        val members: List[Member] = users.map { person =>
          create(person._1, Some(person._2), Some(person._3))
        }
        members
      }
    }

  result match {
    case Success(mlist) => println(s"batch added members: $mlist")
    case Failure(err) => println(s"${err.getMessage}")
  }

  //data row converter
  val toMember = (rs: WrappedResultSet) => Member(
    id = rs.long("id"),
    name = rs.string("name"),
    description = rs.stringOpt("description"),
    birthday = rs.jodaLocalDateOpt("birthday"),
    createdAt = rs.jodaDateTime("created_at")
  )

  val selectSQL: SQL[Member,HasExtractor] = sql"""select * from members""".map(toMember)
  val members: List[Member] = NamedDB(dbname) readOnly { implicit session =>
    selectSQL.list.apply()
  }

  println(s"all members: $members")
  NamedDB('h2mem).close()

注意在过程中我们使用Named???（???)来指定目标数据库连接connection。在上面的配置文件中有一项属性poolFactoryName，它指定了具体使用的数据库连接池工具。scalikeJDBC提供了commons-dbcp,commons-dbcp2,bonecp如下：

poolFactoryName="commons-dbcp"
poolFactoryName="commons=dbcp2"
poolFactoryName="bonecp"

如果配置文件中不提供poolFactoryName的设置，默认为commons-dbcp。翻查了一下，上面这几个连接池管理工具都很陈旧了。想到slick用的是HikariCP，上网看了看2018年还进行了最近更新。下面我们就为scalikeJDBC增加HikariCP连接池管理工具支持。首先，我们需要用TypesafeConfig解析HikariCP配置后构建HikariConfig对象，然后用它来构建HikariDataSource。

下面是配置文件解析代码：

package configdbs
import scala.collection.mutable
import scala.concurrent.duration.Duration
import scala.language.implicitConversions
import com.typesafe.config._
import java.util.concurrent.TimeUnit
import java.util.Properties
import scalikejdbc.config._
import com.typesafe.config.Config
import com.zaxxer.hikari._
import scalikejdbc.ConnectionPoolFactoryRepository

/** Extension methods to make Typesafe Config easier to use */
class ConfigExtensionMethods(val c: Config) extends AnyVal {
  import scala.collection.JavaConverters._

  def getBooleanOr(path: String, default: => Boolean = false) = if(c.hasPath(path)) c.getBoolean(path) else default
  def getIntOr(path: String, default: => Int = 0) = if(c.hasPath(path)) c.getInt(path) else default
  def getStringOr(path: String, default: => String = null) = if(c.hasPath(path)) c.getString(path) else default
  def getConfigOr(path: String, default: => Config = ConfigFactory.empty()) = if(c.hasPath(path)) c.getConfig(path) else default

  def getMillisecondsOr(path: String, default: => Long = 0L) = if(c.hasPath(path)) c.getDuration(path, TimeUnit.MILLISECONDS) else default
  def getDurationOr(path: String, default: => Duration = Duration.Zero) =
    if(c.hasPath(path)) Duration(c.getDuration(path, TimeUnit.MILLISECONDS), TimeUnit.MILLISECONDS) else default

  def getPropertiesOr(path: String, default: => Properties = null): Properties =
    if(c.hasPath(path)) new ConfigExtensionMethods(c.getConfig(path)).toProperties else default

  def toProperties: Properties = {
    def toProps(m: mutable.Map[String, ConfigValue]): Properties = {
      val props = new Properties(null)
      m.foreach { case (k, cv) =>
        val v =
          if(cv.valueType() == ConfigValueType.OBJECT) toProps(cv.asInstanceOf[ConfigObject].asScala)
          else if(cv.unwrapped eq null) null
          else cv.unwrapped.toString
        if(v ne null) props.put(k, v)
      }
      props
    }
    toProps(c.root.asScala)
  }

  def getBooleanOpt(path: String): Option[Boolean] = if(c.hasPath(path)) Some(c.getBoolean(path)) else None
  def getIntOpt(path: String): Option[Int] = if(c.hasPath(path)) Some(c.getInt(path)) else None
  def getStringOpt(path: String) = Option(getStringOr(path))
  def getPropertiesOpt(path: String) = Option(getPropertiesOr(path))
}

object ConfigExtensionMethods {
  @inline implicit def configExtensionMethods(c: Config): ConfigExtensionMethods = new ConfigExtensionMethods(c)
}

trait HikariConfigReader extends TypesafeConfigReader {
  self: TypesafeConfig =>      // with TypesafeConfigReader => //NoEnvPrefix =>

  import ConfigExtensionMethods.configExtensionMethods

  def getFactoryName(dbName: Symbol): String = {
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)
    c.getStringOr("poolFactoryName", ConnectionPoolFactoryRepository.COMMONS_DBCP)
  }

  def hikariCPConfig(dbName: Symbol): HikariConfig = {

    val hconf = new HikariConfig()
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)

    // Connection settings
    if (c.hasPath("dataSourceClass")) {
      hconf.setDataSourceClassName(c.getString("dataSourceClass"))
    } else {
      Option(c.getStringOr("driverClassName", c.getStringOr("driver"))).map(hconf.setDriverClassName _)
    }
    hconf.setJdbcUrl(c.getStringOr("url", null))
    c.getStringOpt("user").foreach(hconf.setUsername)
    c.getStringOpt("password").foreach(hconf.setPassword)
    c.getPropertiesOpt("properties").foreach(hconf.setDataSourceProperties)

    // Pool configuration
    hconf.setConnectionTimeout(c.getMillisecondsOr("connectionTimeout", 1000))
    hconf.setValidationTimeout(c.getMillisecondsOr("validationTimeout", 1000))
    hconf.setIdleTimeout(c.getMillisecondsOr("idleTimeout", 600000))
    hconf.setMaxLifetime(c.getMillisecondsOr("maxLifetime", 1800000))
    hconf.setLeakDetectionThreshold(c.getMillisecondsOr("leakDetectionThreshold", 0))
    hconf.setInitializationFailFast(c.getBooleanOr("initializationFailFast", false))
    c.getStringOpt("connectionTestQuery").foreach(hconf.setConnectionTestQuery)
    c.getStringOpt("connectionInitSql").foreach(hconf.setConnectionInitSql)
    val numThreads = c.getIntOr("numThreads", 20)
    hconf.setMaximumPoolSize(c.getIntOr("maxConnections", numThreads * 5))
    hconf.setMinimumIdle(c.getIntOr("minConnections", numThreads))
    hconf.setPoolName(c.getStringOr("poolName", dbName.name))
    hconf.setRegisterMbeans(c.getBooleanOr("registerMbeans", false))

    // Equivalent of ConnectionPreparer
    hconf.setReadOnly(c.getBooleanOr("readOnly", false))
    c.getStringOpt("isolation").map("TRANSACTION_" + _).foreach(hconf.setTransactionIsolation)
    hconf.setCatalog(c.getStringOr("catalog", null))

    hconf

  }
}

hikariCPConfig函数返回了hconf。下面我们还需要修改DBs.setup调用HikariConfigReader里的函数来构建HikariDataSource已经相关的配置参数：

import scalikejdbc._
trait ConfigDBs {
    self: TypesafeConfigReader with TypesafeConfig with HikariConfigReader =>

  def setup(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    getFactoryName(dbName) match {
      case "hikaricp" => {
        val hconf = hikariCPConfig(dbName)
        val hikariCPSource = new HikariDataSource(hconf)
        if (hconf.getDriverClassName != null && hconf.getDriverClassName.trim.nonEmpty) {
          Class.forName(hconf.getDriverClassName)
        }
        ConnectionPool.add(dbName, new DataSourceConnectionPool(hikariCPSource))
      }
      case _ => {
        val JDBCSettings(url, user, password, driver) = readJDBCSettings(dbName)
        val cpSettings = readConnectionPoolSettings(dbName)
        if (driver != null && driver.trim.nonEmpty) {
          Class.forName(driver)
        }
        ConnectionPool.add(dbName, url, user, password, cpSettings)
      }
    }
  }

  def setupAll(): Unit = {
    loadGlobalSettings()
    dbNames.foreach { dbName => setup(Symbol(dbName)) }
  }

  def close(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    ConnectionPool.close(dbName)
  }

  def closeAll(): Unit = {
    ConnectionPool.closeAll
  }

}


object ConfigDBs extends ConfigDBs
 with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader

case class ConfigDBsWithEnv(envValue: String) extends ConfigDBs
  with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader
  with EnvPrefix {

  override val env = Option(envValue)
}

增加了ConfigDBs对象来替代原来的DBs对象。在ConfigDBs.setup(dbname)实现了HikariCP的调用和配置。ConfigDBsWithEnv可以支持在配置文件中外包一层路径：

dev {
  db {
    h2 {
      driver = "org.h2.Driver"
      url = "jdbc:h2:tcp://localhost/~/slickdemo"
      user = ""
      password = ""
      poolFactoryName = "hikaricp"
      numThreads = 10
      maxConnections = 12
      minConnections = 4
      keepAliveConnection = true
    }
    mysql {
      driver = "com.mysql.jdbc.Driver"
      url = "jdbc:mysql://localhost:3306/testdb"
      user = "root"
      password = "123"
      poolInitialSize = 5
      poolMaxSize = 7
      poolConnectionTimeoutMillis = 1000
      poolValidationQuery = "select 1 as one"
      poolFactoryName = "bonecp"

    }
  }

  # scallikejdbc Global settings
  scalikejdbc.global.loggingSQLAndTime.enabled = true
  scalikejdbc.global.loggingSQLAndTime.logLevel = info
  scalikejdbc.global.loggingSQLAndTime.warningEnabled = true
  scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000
  scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn
  scalikejdbc.global.loggingSQLAndTime.singleLineMode = false
  scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false
  scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10
}

好了，下面是增加了HikariCP的测试代码：

import configdbs._
import scalikejdbc._
import org.joda.time._
import scala.util._   //Try
import scalikejdbc.TxBoundary.Try._
object ConfigureDBs extends App {

  ConfigDBsWithEnv("dev").setupAll()

  val dbname = 'h2

  //clear table object
  try {
    sql"""
        drop table members
          """.execute().apply()(NamedAutoSession(dbname))
  }
  catch {
    case _: Throwable =>
  }

  //construct SQL object
  val createSQL: SQL[Nothing,NoExtractor] =SQL("""
    create table members (
      id bigint primary key auto_increment,
      name varchar(30) not null,
      description varchar(1000),
      birthday date,
      created_at timestamp not null
    )""")

  //run this SQL
  createSQL.execute().apply()(NamedAutoSession(dbname))   //autoCommit

  //data model
  case class Member(
                     id: Long,
                     name: String,
                     description: Option[String] = None,
                     birthday: Option[LocalDate] = None,
                     createdAt: DateTime)

  def create(name: String, birthday: Option[LocalDate], remarks: Option[String])(implicit session: DBSession): Member = {
    val insertSQL: SQL[Nothing,NoExtractor]  =
      sql"""insert into members (name, birthday, description, created_at)
           values (${name}, ${birthday}, ${remarks}, ${DateTime.now})"""
    val id: Long = insertSQL.updateAndReturnGeneratedKey.apply()
    Member(id, name, remarks, birthday,DateTime.now)
  }

  val users = List(
    ("John",new LocalDate("2008-03-01"),"youngest user"),
    ("Susan",new LocalDate("2000-11-03"),"middle aged user"),
    ("Peter",new LocalDate("1983-01-21"),"oldest user"),
  )

  val result: Try[List[Member]] =
    NamedDB(dbname) localTx { implicit session =>
      Try {
        val members: List[Member] = users.map { person =>
          create(person._1, Some(person._2), Some(person._3))
        }
        members
      }
    }

  result match {
    case Success(mlist) => println(s"batch added members: $mlist")
    case Failure(err) => println(s"${err.getMessage}")
  }

  //data row converter
  val toMember = (rs: WrappedResultSet) => Member(
    id = rs.long("id"),
    name = rs.string("name"),
    description = rs.stringOpt("description"),
    birthday = rs.jodaLocalDateOpt("birthday"),
    createdAt = rs.jodaDateTime("created_at")
  )

  val selectSQL: SQL[Member,HasExtractor] = sql"""select * from members""".map(toMember)
  val members: List[Member] = NamedDB(dbname) readOnly { implicit session =>
    selectSQL.list.apply()
  }

  println(s"all members: $members")
  NamedDB('h2mem).close()



}

运行正常！ 

下面是本次讨论的示范源代码：

build.sbt

name := "learn-scalikeJDBC"

version := "0.1"

scalaVersion := "2.12.4"

// Scala 2.10, 2.11, 2.12
libraryDependencies ++= Seq(
  "org.scalikejdbc" %% "scalikejdbc"       % "3.1.0",
  "org.scalikejdbc" %% "scalikejdbc-test"   % "3.1.0"   % "test",
  "org.scalikejdbc" %% "scalikejdbc-config"  % "3.1.0",
  "com.h2database"  %  "h2"                % "1.4.196",
  "mysql" % "mysql-connector-java" % "6.0.6",
  "org.postgresql" % "postgresql" % "9.4-1205-jdbc42",
  "commons-dbcp" % "commons-dbcp" % "1.4",
  "org.apache.tomcat" % "tomcat-jdbc" % "9.0.2",
  "com.zaxxer" % "HikariCP" % "2.7.4",
  "com.jolbox" % "bonecp" % "0.8.0.RELEASE",
  "ch.qos.logback"  %  "logback-classic"   % "1.2.3"
)

resource/application.conf

# JDBC settings
test {
  db {
    h2 {
      driver = "org.h2.Driver"
      url = "jdbc:h2:tcp://localhost/~/slickdemo"
      user = ""
      password = ""
      poolInitialSize = 5
      poolMaxSize = 7
      poolConnectionTimeoutMillis = 1000
      poolValidationQuery = "select 1 as one"
      poolFactoryName = "commons-dbcp2"
    }
  }

  db.mysql.driver = "com.mysql.jdbc.Driver"
  db.mysql.url = "jdbc:mysql://localhost:3306/testdb"
  db.mysql.user = "root"
  db.mysql.password = "123"
  db.mysql.poolInitialSize = 5
  db.mysql.poolMaxSize = 7
  db.mysql.poolConnectionTimeoutMillis = 1000
  db.mysql.poolValidationQuery = "select 1 as one"
  db.mysql.poolFactoryName = "bonecp"

  # scallikejdbc Global settings
  scalikejdbc.global.loggingSQLAndTime.enabled = true
  scalikejdbc.global.loggingSQLAndTime.logLevel = info
  scalikejdbc.global.loggingSQLAndTime.warningEnabled = true
  scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000
  scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn
  scalikejdbc.global.loggingSQLAndTime.singleLineMode = false
  scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false
  scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10
}
dev {
  db {
    h2 {
      driver = "org.h2.Driver"
      url = "jdbc:h2:tcp://localhost/~/slickdemo"
      user = ""
      password = ""
      poolFactoryName = "hikaricp"
      numThreads = 10
      maxConnections = 12
      minConnections = 4
      keepAliveConnection = true
    }
    mysql {
      driver = "com.mysql.jdbc.Driver"
      url = "jdbc:mysql://localhost:3306/testdb"
      user = "root"
      password = "123"
      poolInitialSize = 5
      poolMaxSize = 7
      poolConnectionTimeoutMillis = 1000
      poolValidationQuery = "select 1 as one"
      poolFactoryName = "bonecp"

    }
  }

  # scallikejdbc Global settings
  scalikejdbc.global.loggingSQLAndTime.enabled = true
  scalikejdbc.global.loggingSQLAndTime.logLevel = info
  scalikejdbc.global.loggingSQLAndTime.warningEnabled = true
  scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000
  scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn
  scalikejdbc.global.loggingSQLAndTime.singleLineMode = false
  scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false
  scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10
}

HikariConfig.scala

package configdbs
import scala.collection.mutable
import scala.concurrent.duration.Duration
import scala.language.implicitConversions
import com.typesafe.config._
import java.util.concurrent.TimeUnit
import java.util.Properties
import scalikejdbc.config._
import com.typesafe.config.Config
import com.zaxxer.hikari._
import scalikejdbc.ConnectionPoolFactoryRepository

/** Extension methods to make Typesafe Config easier to use */
class ConfigExtensionMethods(val c: Config) extends AnyVal {
  import scala.collection.JavaConverters._

  def getBooleanOr(path: String, default: => Boolean = false) = if(c.hasPath(path)) c.getBoolean(path) else default
  def getIntOr(path: String, default: => Int = 0) = if(c.hasPath(path)) c.getInt(path) else default
  def getStringOr(path: String, default: => String = null) = if(c.hasPath(path)) c.getString(path) else default
  def getConfigOr(path: String, default: => Config = ConfigFactory.empty()) = if(c.hasPath(path)) c.getConfig(path) else default

  def getMillisecondsOr(path: String, default: => Long = 0L) = if(c.hasPath(path)) c.getDuration(path, TimeUnit.MILLISECONDS) else default
  def getDurationOr(path: String, default: => Duration = Duration.Zero) =
    if(c.hasPath(path)) Duration(c.getDuration(path, TimeUnit.MILLISECONDS), TimeUnit.MILLISECONDS) else default

  def getPropertiesOr(path: String, default: => Properties = null): Properties =
    if(c.hasPath(path)) new ConfigExtensionMethods(c.getConfig(path)).toProperties else default

  def toProperties: Properties = {
    def toProps(m: mutable.Map[String, ConfigValue]): Properties = {
      val props = new Properties(null)
      m.foreach { case (k, cv) =>
        val v =
          if(cv.valueType() == ConfigValueType.OBJECT) toProps(cv.asInstanceOf[ConfigObject].asScala)
          else if(cv.unwrapped eq null) null
          else cv.unwrapped.toString
        if(v ne null) props.put(k, v)
      }
      props
    }
    toProps(c.root.asScala)
  }

  def getBooleanOpt(path: String): Option[Boolean] = if(c.hasPath(path)) Some(c.getBoolean(path)) else None
  def getIntOpt(path: String): Option[Int] = if(c.hasPath(path)) Some(c.getInt(path)) else None
  def getStringOpt(path: String) = Option(getStringOr(path))
  def getPropertiesOpt(path: String) = Option(getPropertiesOr(path))
}

object ConfigExtensionMethods {
  @inline implicit def configExtensionMethods(c: Config): ConfigExtensionMethods = new ConfigExtensionMethods(c)
}

trait HikariConfigReader extends TypesafeConfigReader {
  self: TypesafeConfig =>      // with TypesafeConfigReader => //NoEnvPrefix =>

  import ConfigExtensionMethods.configExtensionMethods

  def getFactoryName(dbName: Symbol): String = {
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)
    c.getStringOr("poolFactoryName", ConnectionPoolFactoryRepository.COMMONS_DBCP)
  }

  def hikariCPConfig(dbName: Symbol): HikariConfig = {

    val hconf = new HikariConfig()
    val c: Config = config.getConfig(envPrefix + "db." + dbName.name)

    // Connection settings
    if (c.hasPath("dataSourceClass")) {
      hconf.setDataSourceClassName(c.getString("dataSourceClass"))
    } else {
      Option(c.getStringOr("driverClassName", c.getStringOr("driver"))).map(hconf.setDriverClassName _)
    }
    hconf.setJdbcUrl(c.getStringOr("url", null))
    c.getStringOpt("user").foreach(hconf.setUsername)
    c.getStringOpt("password").foreach(hconf.setPassword)
    c.getPropertiesOpt("properties").foreach(hconf.setDataSourceProperties)

    // Pool configuration
    hconf.setConnectionTimeout(c.getMillisecondsOr("connectionTimeout", 1000))
    hconf.setValidationTimeout(c.getMillisecondsOr("validationTimeout", 1000))
    hconf.setIdleTimeout(c.getMillisecondsOr("idleTimeout", 600000))
    hconf.setMaxLifetime(c.getMillisecondsOr("maxLifetime", 1800000))
    hconf.setLeakDetectionThreshold(c.getMillisecondsOr("leakDetectionThreshold", 0))
    hconf.setInitializationFailFast(c.getBooleanOr("initializationFailFast", false))
    c.getStringOpt("connectionTestQuery").foreach(hconf.setConnectionTestQuery)
    c.getStringOpt("connectionInitSql").foreach(hconf.setConnectionInitSql)
    val numThreads = c.getIntOr("numThreads", 20)
    hconf.setMaximumPoolSize(c.getIntOr("maxConnections", numThreads * 5))
    hconf.setMinimumIdle(c.getIntOr("minConnections", numThreads))
    hconf.setPoolName(c.getStringOr("poolName", dbName.name))
    hconf.setRegisterMbeans(c.getBooleanOr("registerMbeans", false))

    // Equivalent of ConnectionPreparer
    hconf.setReadOnly(c.getBooleanOr("readOnly", false))
    c.getStringOpt("isolation").map("TRANSACTION_" + _).foreach(hconf.setTransactionIsolation)
    hconf.setCatalog(c.getStringOr("catalog", null))

    hconf

  }
}

import scalikejdbc._
trait ConfigDBs {
    self: TypesafeConfigReader with TypesafeConfig with HikariConfigReader =>

  def setup(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    getFactoryName(dbName) match {
      case "hikaricp" => {
        val hconf = hikariCPConfig(dbName)
        val hikariCPSource = new HikariDataSource(hconf)
        if (hconf.getDriverClassName != null && hconf.getDriverClassName.trim.nonEmpty) {
          Class.forName(hconf.getDriverClassName)
        }
        ConnectionPool.add(dbName, new DataSourceConnectionPool(hikariCPSource))
      }
      case _ => {
        val JDBCSettings(url, user, password, driver) = readJDBCSettings(dbName)
        val cpSettings = readConnectionPoolSettings(dbName)
        if (driver != null && driver.trim.nonEmpty) {
          Class.forName(driver)
        }
        ConnectionPool.add(dbName, url, user, password, cpSettings)
      }
    }
  }

  def setupAll(): Unit = {
    loadGlobalSettings()
    dbNames.foreach { dbName => setup(Symbol(dbName)) }
  }

  def close(dbName: Symbol = ConnectionPool.DEFAULT_NAME): Unit = {
    ConnectionPool.close(dbName)
  }

  def closeAll(): Unit = {
    ConnectionPool.closeAll
  }

}


object ConfigDBs extends ConfigDBs
 with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader

case class ConfigDBsWithEnv(envValue: String) extends ConfigDBs
  with TypesafeConfigReader
  with StandardTypesafeConfig
  with HikariConfigReader
  with EnvPrefix {

  override val env = Option(envValue)
}

ConfigDBs.scala

import configdbs._
import scalikejdbc._
import org.joda.time._
import scala.util._   //Try
import scalikejdbc.TxBoundary.Try._
object ConfigureDBs extends App {

  ConfigDBsWithEnv("dev").setupAll()

  val dbname = 'mysql

  //clear table object
  try {
    sql"""
        drop table members
          """.execute().apply()(NamedAutoSession(dbname))
  }
  catch {
    case _: Throwable =>
  }

  //construct SQL object
  val createSQL: SQL[Nothing,NoExtractor] =SQL("""
    create table members (
      id bigint primary key auto_increment,
      name varchar(30) not null,
      description varchar(1000),
      birthday date,
      created_at timestamp not null
    )""")

  //run this SQL
  createSQL.execute().apply()(NamedAutoSession(dbname))   //autoCommit

  //data model
  case class Member(
                     id: Long,
                     name: String,
                     description: Option[String] = None,
                     birthday: Option[LocalDate] = None,
                     createdAt: DateTime)

  def create(name: String, birthday: Option[LocalDate], remarks: Option[String])(implicit session: DBSession): Member = {
    val insertSQL: SQL[Nothing,NoExtractor]  =
      sql"""insert into members (name, birthday, description, created_at)
           values (${name}, ${birthday}, ${remarks}, ${DateTime.now})"""
    val id: Long = insertSQL.updateAndReturnGeneratedKey.apply()
    Member(id, name, remarks, birthday,DateTime.now)
  }

  val users = List(
    ("John",new LocalDate("2008-03-01"),"youngest user"),
    ("Susan",new LocalDate("2000-11-03"),"middle aged user"),
    ("Peter",new LocalDate("1983-01-21"),"oldest user"),
  )

  val result: Try[List[Member]] =
    NamedDB(dbname) localTx { implicit session =>
      Try {
        val members: List[Member] = users.map { person =>
          create(person._1, Some(person._2), Some(person._3))
        }
        members
      }
    }

  result match {
    case Success(mlist) => println(s"batch added members: $mlist")
    case Failure(err) => println(s"${err.getMessage}")
  }

  //data row converter
  val toMember = (rs: WrappedResultSet) => Member(
    id = rs.long("id"),
    name = rs.string("name"),
    description = rs.stringOpt("description"),
    birthday = rs.jodaLocalDateOpt("birthday"),
    createdAt = rs.jodaDateTime("created_at")
  )

  val selectSQL: SQL[Member,HasExtractor] = sql"""select * from members""".map(toMember)
  val members: List[Member] = NamedDB(dbname) readOnly { implicit session =>
    selectSQL.list.apply()
  }

  println(s"all members: $members")
  NamedDB('h2mem).close()



}