因此，我具有此依赖关系，该依赖关系用于创建表并与Postgres进行交互。这是一个示例类：
class ConfigTable {
this: DBFactory =>
import driver.api._
implicit val configKeyMapper = MappedColumnType.base[ConfigKey, String](e => e.toString, s => ConfigKey.withName(s))
val configs = TableQuery[ConfigMapping]
class ConfigMapping(tag: Tag) extends Table[Config](tag, "configs") {
def key = column[ConfigKey]("key")
def value = column[String]("value")
def * = (key, value) <> (Config.tupled, Config.unapply _)
}
/**
* add config
*
* @param config
* @return
*/
def add(config: Config): Try[Config] = try {
sync(db.run(configs += config)) match {
case 1 => Success(config)
case _ => Failure(new Exception("Unable to add config"))
}
} catch {
case ex: PSQLException =>
if (ex.getMessage.contains("duplicate key value")) Failure(new Exception("alt id already exists."))
else Failure(new Exception(ex.getMessage))
}
def get(key: ConfigKey): Option[Config] = sync(db.run(configs.filter(x => x.key === key).result)).headOption
def getAll(): Seq[Config] = sync(db.run(configs.result))
}
object ConfigTable extends ConfigTable with PSQLComponent
PSQLComponent是数据库元配置的抽象：
导入slick.jdbc.PostgresProfile
trait PSQLComponent extends DBFactory {
val driver = PostgresProfile
import driver.api.Database
val db: Database = Database.forConfig("db.default")
}
DBFactory还是一个抽象：
导入slick.jdbc.JdbcProfile
trait DBFactory {
val driver: JdbcProfile
import driver.api._
val db: Database
}
application.conf：
db.default {
driver = "org.postgresql.Driver"
url = "jdbc:postgresql://localhost:5432/db"
user = "user"
password = "pass"
hikaricp {
minimumIdle = ${db.default.async-executor.minConnections}
maximumPoolSize = ${db.default.async-executor.maxConnections}
}
}
jdbc-defaults.slick.profile = "slick.jdbc.PostgresProfile$"
lagom.persistence.jdbc.create-tables.auto=false
我将此依赖关系编译并发布到联系，并试图在我的Lagom Microservice中使用它。
这是装载程序类：
class SlickExapleAppLoader extends LagomApplicationLoader {
override def load(context: LagomApplicationContext): LagomApplication = new SlickExampleApp(context) {
override def serviceLocator: ServiceLocator = NoServiceLocator
}
override def loadDevMode(context: LagomApplicationContext): LagomApplication = new SlickExampleApp(context) with LagomDevModeComponents {
}
override def describeService = Some(readDescriptor[SlickExampleLMSServiceImpl])
}
abstract class SlickExampleApp(context: LagomApplicationContext)
extends LagomApplication(context)
// No Idea which to use and how, nothing clear from doc too.
// with ReadSideJdbcPersistenceComponents
// with ReadSideSlickPersistenceComponents
// with SlickPersistenceComponents
with AhcWSComponents {
wire[SlickExampleScheduler]
}
我正在尝试在此调度程序中实现它：
class SlickExampleScheduler @Inject()(lmsService: LMSService,
configuration: Configuration)(implicit ec: ExecutionContext) {
val brofile = `SomeDomainObject`
val gson = new Gson()
val concurrency = Runtime.getRuntime.availableProcessors() * 10
implicit val timeout: Timeout = 3.minute
implicit val system: ActorSystem = ActorSystem("LMSActorSystem")
implicit val materializer: ActorMaterializer = ActorMaterializer()
// Getting Exception Initializer here..... For ConfigTable ===> ExceptionLine
val schedulerImplDao = new SchedulerImplDao(ConfigTable)
def hitLMSAPI = {
println("=============>1")
schedulerImplDao.doSomething()
}
system.scheduler.schedule(2.seconds, 2.seconds) {
println("=============>")
hitLMSAPI
}
}
不确定这是正确的方法，还是这不是正确的方法。由于明显的可重用性，将数据模型与服务分开是项目的要求。
异常堆栈：
17:50:38.666 [info] akka.cluster.Cluster(akka://lms-impl-application) [sourceThread=ForkJoinPool-1-worker-1, akkaTimestamp=12:20:38.665UTC, akkaSource=akka.cluster.Cluster(akka://lms-impl-application), sourceActorSystem=lms-impl-application] - Cluster Node [akka.tcp://lms-impl-application@127.0.0.1:45805] - Started up successfully
17:50:38.707 [info] akka.cluster.Cluster(akka://lms-impl-application) [sourceThread=lms-impl-application-akka.actor.default-dispatcher-6, akkaTimestamp=12:20:38.707UTC, akkaSource=akka.cluster.Cluster(akka://lms-impl-application), sourceActorSystem=lms-impl-application] - Cluster Node [akka.tcp://lms-impl-application@127.0.0.1:45805] - No seed-nodes configured, manual cluster join required
java.lang.ExceptionInInitializerError
at com.slick.init.impl.SlickExampleScheduler.<init>(SlickExampleScheduler.scala:29)
at com.slick.init.impl.SlickExampleApp.<init>(SlickExapleAppLoader.scala:42)
at com.slick.init.impl.SlickExapleAppLoader$$anon$2.<init>(SlickExapleAppLoader.scala:17)
at com.slick.init.impl.SlickExapleAppLoader.loadDevMode(SlickExapleAppLoader.scala:17)
at com.lightbend.lagom.scaladsl.server.LagomApplicationLoader.load(LagomApplicationLoader.scala:76)
at play.core.server.LagomReloadableDevServerStart$$anon$1.$anonfun$get$5(LagomReloadableDevServerStart.scala:176)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.core.server.LagomReloadableDevServerStart$$anon$1.$anonfun$get$3(LagomReloadableDevServerStart.scala:173)
at scala.Option.map(Option.scala:163)
at play.core.server.LagomReloadableDevServerStart$$anon$1.$anonfun$get$2(LagomReloadableDevServerStart.scala:149)
at scala.util.Success.flatMap(Try.scala:251)
at play.core.server.LagomReloadableDevServerStart$$anon$1.$anonfun$get$1(LagomReloadableDevServerStart.scala:147)
at scala.concurrent.Future$.$anonfun$apply$1(Future.scala:658)
at scala.util.Success.$anonfun$map$1(Try.scala:255)
at scala.util.Success.map(Try.scala:213)
at scala.concurrent.Future.$anonfun$map$1(Future.scala:292)
at scala.concurrent.impl.Promise.liftedTree1$1(Promise.scala:33)
at scala.concurrent.impl.Promise.$anonfun$transform$1(Promise.scala:33)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:64)
at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1402)
at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: java.lang.NullPointerException
at com.example.db.models.LoginTable.<init>(LoginTable.scala:29)
at com.example.db.models.LoginTable$.<init>(LoginTable.scala:293)
at com.example.db.models.LoginTable$.<clinit>(LoginTable.scala)
... 24 more
答案 0 :(得分：0)
这是它的运作方式：
abstract class SlickExampleApp(context: LagomApplicationContext) extends LagomApplication(context)
with SlickPersistenceComponents with AhcWSComponents {
override implicit lazy val actorSystem: ActorSystem = ActorSystem("LMSActorSystem")
override lazy val materializer: ActorMaterializer = ActorMaterializer()
override lazy val lagomServer = serverFor[SlickExampleLMSService](wire[SlickExampleLMSServiceImpl])
lazy val externalService = serviceClient.implement[LMSService]
override def connectionPool: ConnectionPool = new HikariCPConnectionPool(environment)
override def jsonSerializerRegistry: JsonSerializerRegistry = new JsonSerializerRegistry {
override def serializers: immutable.Seq[JsonSerializer[_]] = Vector.empty
}
val loginTable = wire[LoginTable]
wire[SlickExampleScheduler]
}
>我要报告的一件事是：Lagom docs关于slick的application.conf配置是不正确的，它误导了我两天，自由代码，它是这样的：
private val readSideConfig = system.settings.config.getConfig("lagom.persistence.read-side.jdbc")
private val jdbcConfig = system.settings.config.getConfig("lagom.persistence.jdbc")
private val createTables = jdbcConfig.getConfig("create-tables")
val autoCreateTables: Boolean = createTables.getBoolean("auto")
// users can disable the usage of jndiDbName for userland read-side operations by
// setting the jndiDbName to null. In which case we fallback to slick.db.
// slick.db must be defined otherwise the application will fail to start
val db = {
if (readSideConfig.hasPath("slick.jndiDbName")) {
new InitialContext()
.lookup(readSideConfig.getString("slick.jndiDbName"))
.asInstanceOf[Database]
} else if (readSideConfig.hasPath("slick.db")) {
Database.forConfig("slick.db", readSideConfig)
} else {
throw new RuntimeException("Cannot start because read-side database configuration is missing. " +
"You must define either 'lagom.persistence.read-side.jdbc.slick.jndiDbName' or 'lagom.persistence.read-side.jdbc.slick.db' in your application.conf.")
}
}
val profile = DatabaseConfig.forConfig[JdbcProfile]("slick", readSideConfig).profile
所需的配置与Doc上建议的配置有很大不同。