UnsupportedClassVersionError on running play application with JDK 1.7

Question

Just now started learning Play framework for my project requirement and my project only build on JDK 1.7 so I have downloaded Play 2.3.9 ve

Answer 1

52 = Java 8, 51 = Java 7.. On com.typesafe.config.ConfigException; so you have a too new library.

Answer 2

Although it seemed I was using the same version for java and javac:

• java -version java version "1.8.0_51"
• javac -version javac 1.8.0_51

My problem was (Linux Mint 17.1) that I had installed oracle-java7 and oracle-java8 so somewhere there must be a misconfiguration.

I uninstalled oracle-java7 and everything worked fine to me.

Answer 3

Description :

• Java SE 8 = 52
• Java SE 7 = 51
• Java SE 6.0 = 50

Java 8 has major version 52, which means if we run javac command from Java 8 installation, it will by default generate a class with major version 52. However, if we run class file in JRE 7, we will get "Unsupported major.minor version 52.0".

Solution :

There was a mis configuration in %JAVA_HOME%

• java -version java version "1.8.0_45"

• javac -version javac 1.8.0_45

• @echo %JAVA_HOME% C:\Program Files\Java\jdk1.7.0_75

To set the path temporary

• set JAVA_HOME=C:\Program Files\Java\jdk1.8.0_45

• @echo %JAVA_HOME% C:\Program Files\Java\jdk1.8.0_45

Answer 4

Faced similar issue, resolved by changing version

//addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.5.0")
addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.3.9")

With above changes below exception got resolved (note: system has java 7)

Exception got with higher version:

[info] Set current project to helloworld (in build file:/Users/suniltonger/Projects/play/helloworld/helloworld/)
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:559)
    at com.typesafe.sbt.web.SbtWeb$$anonfun$com$typesafe$sbt$web$SbtWeb$$load$1.apply(SbtWeb.scala:559)
    at scala.Option.fold(Option.scala:157)
    at com.typesafe.sbt.web.SbtWeb$.com$typesafe$sbt$web$SbtWeb$$load(SbtWeb.scala:573)
    at com.typesafe.sbt.web.SbtWeb$$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:503)
    at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:484)
    at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:484)
    at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
    at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
    at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
    at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
    at sbt.Command$.process(Command.scala:93)
    at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
    at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
    at sbt.State$$anon$1.process(State.scala:184)
    at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
    at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
    at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
    at sbt.MainLoop$.next(MainLoop.scala:96)
    at sbt.MainLoop$.run(MainLoop.scala:89)
    at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:68)
    at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:63)
    at sbt.Using.apply(Using.scala:24)
    at sbt.MainLoop$.runWithNewLog(MainLoop.scala:63)
    at sbt.MainLoop$.runAndClearLast(MainLoop.scala:46)
    at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:30)
    at sbt.MainLoop$.runLogged(MainLoop.scala:22)
    at sbt.StandardMain$.runManaged(Main.scala:54)
    at sbt.xMain.run(Main.scala:29)
    at xsbt.boot.Launch$$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
[error] Use 'last' for the full log.
[debug] > load-failed

Answer 5

ConfigException occurs because from version 1.3.0, com.typesafe.config library is only compatible with JDK8; see README. You need to downgrade the library version. Use

"com.typesafe" % "config" % "1.2.1"

Answer 6

Indeed what @cib is saying solves my problem. Just modify the file plugins.sbt in my projet directory.

Change the line :

addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.4.2")

to:

addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.3.9")

and you'll not get any errors doing activator run again.