Question

我试图用Postgres中创建的1个表来练习一个简单的光滑示例。它涉及4个文件。

这是我的DAO.scala文件

import slick.dbio.Effect.Write
import slick.lifted.{CanBeQueryCondition, Rep, Tag}
import slick.jdbc.PostgresProfile.api._
import slick.sql.FixedSqlAction

import scala.concurrent.Future
import scala.reflect._

trait BaseEntity {
  val id: Long
  val isDeleted: Boolean
}

abstract class BaseTable[E: ClassTag](tag: Tag, schemaName: Option[String], tableName: String)
  extends Table[E](tag, schemaName, tableName) {

  val classOfEntity = classTag[E].runtimeClass

  val id: Rep[Long] = column[Long]("Id", O.PrimaryKey, O.AutoInc)
  val isDeleted: Rep[Boolean] = column[Boolean]("IsDeleted", O.Default(false))
}

trait BaseRepositoryComponent[T <: BaseTable[E], E <: BaseEntity] {
  def getById(id: Long): Future[Option[E]]

  def getAll: Future[Seq[E]]

  def filter[C <: Rep[_]](expr: T => C)(implicit wt: CanBeQueryCondition[C]): Future[Seq[E]]

  def save(row: E): Future[E]

  def deleteById(id: Long): Future[Int]

  def updateById(id: Long, row: E): Future[Int]
}

trait BaseRepositoryQuery[T <: BaseTable[E], E <: BaseEntity] {

   val query: slick.jdbc.PostgresProfile.api.type#TableQuery[T]

  def getByIdQuery(id: Long): Query[T, E, Seq] = {
    query.filter(_.id === id).filter(_.isDeleted === false)
  }

  def getAllQuery: Query[T, E, Seq] = {
    query.filter(_.isDeleted === false)
  }

  def filterQuery[C <: Rep[_]](expr: T => C)(implicit wt:     CanBeQueryCondition[C]): Query[T, E, Seq] = {
    query.filter(expr).filter(_.isDeleted === false)
  }

  def saveQuery(row: E): FixedSqlAction[E, NoStream, Write] = {
    query returning query += row
  }

  def deleteByIdQuery(id: Long): FixedSqlAction[Int, NoStream, Write]={
query.filter(_.id === id).map(_.isDeleted).update(true)
  }

  def updateByIdQuery(id: Long, row: E): FixedSqlAction[Int, NoStream, Write] = {
    query.filter(_.id === id).filter(_.isDeleted === false).update(row)
  }

}

abstract class BaseRepository[T <: BaseTable[E], E <: BaseEntity :    ClassTag](clazz: TableQuery[T])
  extends BaseRepositoryQuery[T, E]
 with BaseRepositoryComponent[T, E] {
   val clazzTable: TableQuery[T] = clazz
  lazy val clazzEntity = classTag[E].runtimeClass
  val query: slick.jdbc.PostgresProfile.api.type#TableQuery[T] = clazz
  val user = "postgres"
  val url = "jdbc:postgresql://localhost:5432/learning"
  val password = "admin"
 val driver = "org.postgresql.Driver"


  val db = Database.forURL(url, user = user, password = password, driver = driver)

  def getAll: Future[Seq[E]] = {
    db.run(getAllQuery.result)
  }

  def getById(id: Long): Future[Option[E]] = {
    db.run(getByIdQuery(id).result.headOption)
  }

  def filter[C <: Rep[_]](expr: T => C)(implicit wt: CanBeQueryCondition[C]): Future[Seq[E]] = {
db.run(filterQuery(expr).result)
  }

  def save(row: E): Future[E] = {
    db.run(saveQuery(row))
  }

  def updateById(id: Long, row: E): Future[Int] = {
    db.run(updateByIdQuery(id, row))
  }

 def deleteById(id: Long): Future[Int] = {
    db.run(deleteByIdQuery(id))
  }

}

这是我的entities.scala文件

import slick.jdbc.PostgresProfile.api._
import slick.lifted.ProvenShape.proveShapeOf
import slick.lifted.{Rep, Tag}

class EmployeeTable(_tableTag: Tag) extends BaseTable[Employee]    (_tableTag, Some("learning"), "Employee") {

  def * = (id, firstName, isDeleted) <>(Employee.tupled,     Employee.unapply)

  def ? = (Rep.Some(id), Rep.Some(firstName),    Rep.Some(isDeleted)).shaped.<>({ r => import r._; _1.map(_ => Employee.tupled((_1.get, _2.get, _3.get))) }, (_: Any) => throw new Exception("Inserting into ? projection not supported."))

  override val id: Rep[Long] = column[Long]("EmployeeId", O.AutoInc, O.PrimaryKey)
  val firstName: Rep[String] = column[String]("FirstName")
  override val isDeleted: Rep[Boolean] = column[Boolean]("IsDeleted")
  lazy val employeeTable = new TableQuery(tag => new EmployeeTable(tag))

}


case class Employee(id: Long, firstName: String, isDeleted: Boolean)     extends BaseEntity

这是我的build.scala文件。

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.12.0"

libraryDependencies ++= Seq(
   "com.typesafe.slick" % "slick_2.11" % "3.2.0-M1",
  "org.postgresql" % "postgresql" % "9.4.1211"
)

最后是我的EmployeeRepository.scala文件

import slick.lifted.TableQuery
import scala.concurrent.ExecutionContext.Implicits.global
abstract class EmployeeRepository
 extends  BaseRepository[EmployeeTable, Employee](TableQuery[EmployeeTable]){

   def insertItem(row: Employee) = {
       super.save(row)
   }

}

object ImplEmployeeRepository extends EmployeeRepository

object TestEmp extends App {

  val emp = Employee(0L, "aamir", false)

  for {
    result <- ImplEmployeeRepository.insertItem(emp)
    _ = println(result)
  } yield result
  Thread.sleep(5000)

}

我一跑“TestEmp＆＃39;对象抛出此异常：

线程中的异常＆＃34; main＆＃34; java.lang.NoClassDefFoundError：scala / Product $ class at slick.ast.ColumnOption $ PrimaryKey $。（ColumnOption.scala：15） at slick.ast.ColumnOption $ PrimaryKey $。（ColumnOption.scala） at slick.relational.RelationalTableComponent $ ColumnOptions $ class。$ init $（RelationalProfile.scala：110） at slick.relational.RelationalTableComponent $$ anon $ 2.（RelationalProfile.scala：116） at slick.relational.RelationalTableComponent $ class。$ init $（RelationalProfile.scala：116） at slick.jdbc.PostgresProfile $。（PostgresProfile.scala：245） at slick.jdbc.PostgresProfile $。（PostgresProfile.scala）在BaseRepository。（DAO.scala：78）在EmployeeRepository。（EmployeeRepository.scala：3）在ImplEmployeeRepository $。（EmployeeRepository.scala：11）在ImplEmployeeRepository $。（EmployeeRepository.scala）在TestEmp $ .delayedEndpoint $ TestEmp $ 1（EmployeeRepository.scala：18）在TestEmp $ delayedInit $ body.apply（EmployeeRepository.scala：13）在scala.runtime.AbstractFunction0.apply $ mcV $ sp（AbstractFunction0.scala：12）在scala.App。$ anonfun $ main $ 1 $ adapt（App.scala：76）在scala.App $$ Lambda $ 5 / 305808283.apply（未知来源）在scala.collection.immutable.List.foreach（List.scala：378）在scala.App.main（App.scala：76）在scala.App.main $（App.scala：74）在TestEmp $ .main（EmployeeRepository.scala：13）在TestEmp.main（EmployeeRepository.scala） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:497）在com.intellij.rt.execution.application.AppMain.main（AppMain.java:144）引起：java.lang.ClassNotFoundException：scala.Product $ class at java.net.URLClassLoader.findClass（URLClassLoader.java:381） at java.lang.ClassLoader.loadClass（ClassLoader.java:424） at sun.misc.Launcher $ AppClassLoader.loadClass（Launcher.java:331） at java.lang.ClassLoader.loadClass（ClassLoader.java:357） ......还有26个

我无法弄清楚究竟是什么问题？

Answer 1

您的Scala编译器版本为2.12，但您的光滑版本为2.11。

将光滑版本更改为2.12或将Scala编译器版本更改为2.11

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.12.0"

libraryDependencies ++= Seq(
   "com.typesafe.slick" % "slick_2.11" % "3.2.0-M1", //error is here
  "org.postgresql" % "postgresql" % "9.4.1211"
)

更改了正确的build.sbt

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.11.8"

libraryDependencies ++= Seq(
   "com.typesafe.slick" % "slick_2.11" % "3.2.0-M1",
  "org.postgresql" % "postgresql" % "9.4.1211"
)

或

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.11.0"

libraryDependencies ++= Seq(
   "com.typesafe.slick" %% "slick" % "3.2.0-M1", //notice double %%
  "org.postgresql" % "postgresql" % "9.4.1211"
)

或使用Scala编译器2.12

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.12.0"

libraryDependencies ++= Seq(
   "com.typesafe.slick" %% "slick" % "3.2.0-M1",
  "org.postgresql" % "postgresql" % "9.4.1211"
)

或Scala编译器2.12

name := "SlickAkka"

version := "1.0"

scalaVersion := "2.12.0"

libraryDependencies ++= Seq(
   "com.typesafe.slick" % "slick_2.12" % "3.2.0-M1",
  "org.postgresql" % "postgresql" % "9.4.1211"
)

简单光滑示例Scala

1 个答案: