major.minor non supportato versione 51.0 durante l'esecuzione del framework di gioco

Question

So che esiste un conflitto di versione. Voglio solo che qualcuno mi dica come risolverlo. Nel precedente post StackOverflow nessuno indica la soluzione.

Versioni: Ubuntu: 12.04.1 LTS java: 1.6.0_24 (OpenJDK) javac: 1.7.0_07 (OpenJDK)

haider@haider-desktop:~/Documents/projects/java-projects/mytestapp$ play 
[info] Loading project definition from /home/haider/Documents/projects/java-projects/mytestapp/project 
[info] Set current project to mytestapp (in build file:/home/haider/Documents/projects/java-projects/mytestapp/) 
     _   _ 
_ __ | | __ _ _ _| | 
| '_ \| |/ _' | || |_| 
| __/|_|\____|\__ (_) 
|_|   |__/ 

play! 2.0.4, http://www.playframework.org 

> Type "help play" or "license" for more information. 
> Type "exit" or use Ctrl+D to leave this console. 

[mytestapp] $ run 

--- (Running the application from SBT, auto-reloading is enabled) --- 
[info] play - Listening for HTTP on port 9000... 

(Server started, use Ctrl+D to stop and go back to the console...) 

[info] Compiling 5 Scala sources and 2 Java sources to /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/classes... 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes$javascript : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes$ref : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes$javascript : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/target/scala-2.9.1/src_managed/main/controllers/routes.java : java.lang.UnsupportedClassVersionError: controllers/routes$ref : Unsupported major.minor version 51.0 
[warn] Error reading API from class file : java.lang.UnsupportedClassVersionError: controllers/routes$javascript : Unsupported major.minor version 51.0 
[warn] Error reading API from class file : java.lang.UnsupportedClassVersionError: controllers/routes : Unsupported major.minor version 51.0 
[warn] Error reading API from class file : java.lang.UnsupportedClassVersionError: controllers/routes$ref : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/app/controllers/Application.java : java.lang.UnsupportedClassVersionError: controllers/Application$Hello : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/app/controllers/Application.java : java.lang.UnsupportedClassVersionError: controllers/Application : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/app/controllers/Application.java : java.lang.UnsupportedClassVersionError: controllers/Application$Hello : Unsupported major.minor version 51.0 
[warn] Problem processing dependencies of source /home/haider/Documents/projects/libraries/play-2.0.4/samples/java/helloworld/app/controllers/Application.java : java.lang.UnsupportedClassVersionError: controllers/Application : Unsupported major.minor version 51.0 
[warn] Error reading API from class file : java.lang.UnsupportedClassVersionError: controllers/Application$Hello : Unsupported major.minor version 51.0 
[warn] Error reading API from class file : java.lang.UnsupportedClassVersionError: controllers/Application : Unsupported major.minor version 51.0 
[info] play - Application started (Dev) 

Answer 1

Si sta utilizzando versioni differenti JDK per compilare ed eseguire l'applicazione . Tu dici che:

java: 1.6.0_24 (OpenJDK) 
javac: 1.7.0_07 (OpenJDK) 

Così il vostro compilatore (javac) è una versione più recente del Java comando , il che significa che il secondo non è possibile eseguire i file compilati. È necessario utilizzare solo 1 versione del JDK (stessa cosa per Java e javac)

Answer 2

Su Ubuntu a cambiare versione di Java sia per la compilazione e l'esecuzione necessario chiamare:

sudo update-alternatives --config javac 

e

sudo update-alternatives --config java 

Answer 3

Una soluzione migliore è quella di cambiare la versione di destinazione, così si potrebbe compilare a 1,6 da 1,7 in questo modo: How can I set the javac compile version for Play Framework 2.0 to prevent "Unsupported major.minor version"?

mettere questo nel vostro Corporatura .scala:

val main = play.Project(appName, appVersion, appDependencies).settings(
    // Force compilation in java 1.6 
    javacOptions in Compile ++= Seq("-source", "1.6", "-target", "1.6") 
)