启动Play Framework服务器时遇SLF4J依赖冲突错误求助

项目依赖配置 #

"io.getquill" %% "quill-jdbc" % "4.3.0",
"org.postgresql" %  "postgresql" % "42.3.1",
"com.h2database" % "h2" % "1.4.199",

"org.tpolecat" %% "doobie-core"     % DoobieVersion,
"org.tpolecat" %% "doobie-postgres" % DoobieVersion,
"org.tpolecat" %% "doobie-h2" % DoobieVersion,
"org.tpolecat" %% "doobie-hikari"   % DoobieVersion,

"com.typesafe.play" %% "play-json" % "2.9.3",
"com.typesafe.play" %% "play-json-joda" % "2.9.3",

// 线程与流处理库
"io.monix" %% "monix-execution" % "3.4.0",
"io.monix" %% "monix-reactive" % "3.4.1" exclude("org.typelevel", "cats-effect_2.13"),
"org.typelevel" %% "cats-effect" % "3.5.1",

// 测试库
"org.scalatestplus.play" %% "scalatestplus-play" % "5.1.0" % Test,
"org.specs2" %% "specs2-core" % "4.20.0" % Test,
"org.scalacheck" %% "scalacheck" % "1.14.1" % Test

启动错误信息 #

SLF4J: No SLF4J providers were found.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#noProviders for further details.
SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions prior to 1.8.
SLF4J: Ignoring binding found at [jar:file:/home/joesan/.cache/coursier/v1/https/repo1.maven.org/maven2/ch/qos/logback/logback-classic/1.2.11/logback-classic-1.2.11.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#ignoredBindings for an explanation.
[error] java.lang.ClassCastException: class org.slf4j.helpers.NOPLoggerFactory cannot be cast to class ch.qos.logback.classic.LoggerContext (org.slf4j.helpers.NOPLoggerFactory and ch.qos.logback.classic.LoggerContext are in unnamed module of loader play.runsupport.NamedURLClassLoader @b900ff7)
[error]         at play.api.libs.logback.LogbackLoggerConfigurator.configure(LogbackLoggerConfigurator.scala:91)
[error]         at play.api.libs.logback.LogbackLoggerConfigurator.init(LogbackLoggerConfigurator.scala:31)
[error]         at play.core.server.DevServerStart$.$anonfun$mainDev$1(DevServerStart.scala:106)
[error]         at play.utils.Threads$.withContextClassLoader(Threads.scala:22)
[error]         at play.core.server.DevServerStart$.mainDev(DevServerStart.scala:76)
[error]         at play.core.server.DevServerStart$.mainDevHttpMode(DevServerStart.scala:50)
[error]         at play.core.server.DevServerStart.mainDevHttpMode(DevServerStart.scala)
[error]         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error]         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[error]         at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error]         at java.base/java.lang.reflect.Method.invoke(Method.java:566)
[error]         at play.runsupport.Reloader$.startDevMode(Reloader.scala:306)
[error]         at play.sbt.run.PlayRun$.devModeServer$lzycompute$1(PlayRun.scala:100)
[error]         at play.sbt.run.PlayRun$.devModeServer$1(PlayRun.scala:83)
[error]         at play.sbt.run.PlayRun$.$anonfun$playRunTask$3(PlayRun.scala:107)
[error]         at play.sbt.run.PlayRun$.$anonfun$playRunTask$3$adapted(PlayRun.scala:67)
[error]         at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] stack trace is suppressed; run last Compile / run for the full output
[error] (Compile / run) java.lang.reflect.InvocationTargetException
[error] Total time: 1 s, completed Sep 6, 2023, 9:33:00 PM

sbt evicted执行结果 #

[warn]  * org.slf4j:slf4j-api:2.0.7 is selected over {1.7.30, 1.7.36, 1.7.36, 1.7.36, 1.7.30, 2.0.0-alpha1, 1.7.25, 1.7.36, 1.7.36, 1.7.32}
[warn]      +- ch.qos.logback:logback-classic:1.4.11              (depends on 2.0.7)
[warn]      +- org.tpolecat:doobie-hikari_2.13:1.0.0-RC1          (depends on 1.7.32)
[warn]      +- org.slf4j:jul-to-slf4j:1.7.36                      (depends on 1.7.36)
[warn]      +- org.slf4j:jcl-over-slf4j:1.7.36                    (depends on 1.7.36)
[warn]      +- org.java-websocket:Java-WebSocket:1.4.0            (depends on 1.7.25)
[warn]      +- com.zaxxer:HikariCP:4.0.3                          (depends on 2.0.0-alpha1)
[warn]      +- com.typesafe.scala-logging:scala-logging_2.13:3.9.4 (depends on 1.7.30)
[warn]      +- com.typesafe.play:play_2.13:2.8.19                 (depends on 1.7.36)
[warn]      +- com.typesafe.akka:akka-slf4j_2.13:2.6.20           (depends on 1.7.36)
[warn]      +- com.typesafe.akka:akka-actor-typed_2.13:2.6.20     (depends on 1.7.36)
[warn]      +- com.openelectrons:ocpp-j-api_2.13:0.0.1-SNAPSHOT   (depends on 1.7.30)

问题分析 #

从sbt evicted结果能看出，项目中slf4j-api被解析为2.0.7版本，但你使用的Play Framework 2.8.19依赖的是slf4j-api:1.7.36。SLF4J 2.x和1.x的日志绑定机制完全不同：

• SLF4J 1.x依赖StaticLoggerBinder类绑定日志实现
• SLF4J 2.x改用ServiceLoader加载日志提供者

当前项目同时存在logback-classic:1.4.11（依赖slf4j-api 2.0.7）和Play自带的logback-classic:1.2.11（依赖slf4j-api 1.7.x）。SLF4J 2.x会忽略1.x的绑定实现，导致没有可用的日志提供者，最终使用NOPLoggerFactory。而Play的日志配置器试图将这个NOPLoggerFactory强制转换为Logback的LoggerContext，从而抛出ClassCastException。

解决方案 #

1. 强制统一slf4j-api版本为1.7.36 #

在build.sbt中添加强制依赖，确保所有模块都使用Play兼容的SLF4J版本：

libraryDependencies += "org.slf4j" % "slf4j-api" % "1.7.36" force()

2. 统一logback-classic版本为1.2.11 #

强制指定logback-classic版本，避免高版本logback引入不兼容的slf4j-api：

libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.2.11" force()

3. 验证修复效果 #

执行以下命令清理并更新依赖，确认冲突已解决：

sbt clean update evicted

检查输出中slf4j-api的版本是否统一为1.7.36，且没有更高版本被选中。

4. 可选：排除冲突依赖 #

如果某个特定依赖引入了高版本的slf4j或logback，可以直接在该依赖上排除，比如针对doobie依赖：

"org.tpolecat" %% "doobie-hikari" % DoobieVersion exclude("org.slf4j", "slf4j-api")

不过强制版本的方式更直接，适合多依赖冲突的场景。

内容的提问来源于stack exchange，提问作者joesan