play がいろいろと変わっているので、いろいろと走り書き

logback.xml を使え

<!-- https://www.playframework.com/documentation/latest/SettingsLogger -->
<configuration>

    <conversionRule conversionWord="coloredLevel" converterClass="play.api.libs.logback.ColoredLevel"/>

    <appender name="FILE" class="ch.qos.logback.core.FileAppender">
        <file>${application.home:-.}/logs/application.log</file>
        <encoder>
            <pattern>%date [%level] from %logger in %thread - %message%n%xException</pattern>
        </encoder>
    </appender>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%coloredLevel %logger{15} - %message%n%xException{10}</pattern>
        </encoder>
    </appender>

    <appender name="ASYNCFILE" class="ch.qos.logback.classic.AsyncAppender">
        <appender-ref ref="FILE"/>
    </appender>

    <appender name="ASYNCSTDOUT" class="ch.qos.logback.classic.AsyncAppender">
        <appender-ref ref="STDOUT"/>
    </appender>

    <logger name="play" level="INFO"/>
    <logger name="application" level="DEBUG"/>

    <!-- Off these ones as they are annoying, and anyway we manage configuration ourselves -->
    <logger name="com.avaje.ebean.config.PropertyMapLoader" level="OFF"/>
    <logger name="com.avaje.ebeaninternal.server.core.XmlConfigLoader" level="OFF"/>
    <logger name="com.avaje.ebeaninternal.server.lib.BackgroundThread" level="OFF"/>
    <logger name="com.gargoylesoftware.htmlunit.javascript" level="OFF"/>

    <root level="WARN">
        <appender-ref ref="ASYNCFILE"/>
        <appender-ref ref="ASYNCSTDOUT"/>
    </root>

</configuration>

GlobalSettings それ死んだよ

import javax.inject.{Inject, Singleton}

import play.api.{Application, Logger}
import play.api.inject.ApplicationLifecycle

import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.Future

@Singleton
class AppSettings @Inject()(lifecycle: ApplicationLifecycle, application: Application) {

  Logger.info("Start application...")
  // 旧 onStart の内容

  lifecycle.addStopHook(() => Future {
    Logger.info("Shutdown application...")
    // 旧 onStop の内容
  })

}

import com.google.inject.AbstractModule

class Module extends AbstractModule {

  def configure() = {
    bind(classOf[AppSettings]).asEagerSingleton()
  }

}

sbt 0.13.12 から build.sbt 使え