java - 使用 JDK 1.7 运行 Play 应用程序时出现 UnsupportedClassVersionError

Question

刚刚开始为我的项目需求学习 Play 框架，我的项目仅基于 JDK 1.7，所以我下载了 Play 2.3.9 版本并创建了一个示例项目输入 activator new。然后移动到示例项目目录并执行activator run。然后我看到 JDK 不兼容的异常。我必须在哪里进行更改才能处理此问题？

日志:

[info] Loading project definition from E:\workspace\play\first-app\project
[info] Set current project to first-app (in build file:/E:/workspace/play/first-app/)
java.lang.UnsupportedClassVersionError: com/typesafe/config/ConfigException : Unsupported major.minor version 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        at com.typesafe.sbt.web.SbtWeb$$anonfun$com$typesafe$sbt$web$SbtWeb$$load$1.apply(SbtWeb.scala:535)
        at com.typesafe.sbt.web.SbtWeb$$anonfun$com$typesafe$sbt$web$SbtWeb$$load$1.apply(SbtWeb.scala:535)
        at scala.Option.fold(Option.scala:157)
        at com.typesafe.sbt.web.SbtWeb$.com$typesafe$sbt$web$SbtWeb$$load(SbtWeb.scala:549)
        at com.typesafe.sbt.web.SbtWeb$$anonfun$globalSettings$1$$anonfun$apply$1.apply(SbtWeb.scala:143)
        at com.typesafe.sbt.web.SbtWeb$$anonfun$globalSettings$1$$anonfun$apply$1.apply(SbtWeb.scala:143)
        at scala.Function1$$anonfun$andThen$1.apply(Function1.scala:55)
        at sbt.Project$.setProject(Project.scala:319)
        at sbt.BuiltinCommands$.doLoadProject(Main.scala:484)
        at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:475)
        at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:475)
        at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:58)
        at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:58)
        at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:60)
        at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:60)
        at sbt.Command$.process(Command.scala:92)
        at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:98)
        at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:98)
        at sbt.State$$anon$1.process(State.scala:184)
        at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:98)
        at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:98)
        at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
        at sbt.MainLoop$.next(MainLoop.scala:98)
        at sbt.MainLoop$.run(MainLoop.scala:91)
        at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:70)
        at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:65)
        at sbt.Using.apply(Using.scala:24)
        at sbt.MainLoop$.runWithNewLog(MainLoop.scala:65)
        at sbt.MainLoop$.runAndClearLast(MainLoop.scala:48)
        at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:32)
        at sbt.MainLoop$.runLogged(MainLoop.scala:24)
        at sbt.StandardMain$.runManaged(Main.scala:53)
        at sbt.xMain.run(Main.scala:28)
        at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
        at xsbt.boot.Launch$.withContextLoader(Launch.scala:128)
        at xsbt.boot.Launch$.run(Launch.scala:109)
        at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:35)
        at xsbt.boot.Launch$.launch(Launch.scala:117)
        at xsbt.boot.Launch$.apply(Launch.scala:18)
        at xsbt.boot.Boot$.runImpl(Boot.scala:41)
        at xsbt.boot.Boot$.main(Boot.scala:17)
        at xsbt.boot.Boot.main(Boot.scala)
[error] java.lang.UnsupportedClassVersionError: com/typesafe/config/ConfigException : Unsupported major.minor version 52.0

Answer 1

52 = Java 8, 51 = Java 7.. 开启 com.typesafe.config.ConfigException ;所以你的图书馆太新了。