使用postgres驱动程序处理灵活的数据库配置问题

Question

我正在尝试用slick和postgres设置一个简单的play 2.5应用程序，但似乎无法克服错误。

我所犯的错误是

[error] p.a.d.s.DefaultSlickApi - Failed to create Slick database config for key default.
slick.SlickException: Error getting instance of profile "slick.jdbc.PostgresProfile"
...
Caused by: java.lang.InstantiationException: slick.jdbc.PostgresProfile
...
Caused by: java.lang.NoSuchMethodException: slick.jdbc.PostgresProfile.<init>()
...

我的application.conf中有以下内容

slick.dbs.default {
  driver = "slick.jdbc.PostgresProfile"
  db = {
    driver = "org.postgresql.Driver"

    user = postgres
    host = localhost
    port = 5432
    password = ""

    host = ${?EVENTUAL_DB_HOST}
    port = ${?EVENTUAL_DB_PORT}
    user = ${?EVENTUAL_DB_USER}
    password = ${?EVENTUAL_DB_PW}
    url = "jdbc:postgresql://"${slick.dbs.default.db.host}":"${slick.dbs.default.db.port}"/"${slick.dbs.default.db.user}
  }
}

而这些在我的依赖关系中

  "com.typesafe.play" %% "play-slick" % "2.1.0",
  "com.typesafe.slick" %% "slick-codegen" % "3.1.1",
  "com.github.tminglei" %% "slick-pg" % "0.15.0-RC", //"0.14.6",
  "org.postgresql" % "postgresql" % "42.0.0"

如果我将slick.dbs.default.driver更改为slick.driver.PostgresDriver (显然现在已不再推荐)，我将得到

[error] p.a.d.s.DefaultSlickApi - Failed to create Slick database config for key default.
slick.SlickException: Error getting instance of profile "slick.driver.PostgresDriver"
...
Caused by: java.lang.ClassNotFoundException: slick.driver.PostgresDriver
...

我想把头发拔出来，却找不到其他的资源。有人知道这是怎么回事吗？

Answer 1

当然，根据insan-e的推荐，我所要做的就是添加一个$。所以slick.dbs.default.driver应该是"slick.jdbc.PostgresProfile$"。