versión major.minor no compatible 51.0 mientras se ejecuta el marco de juego

Question

Sé que hay un conflicto de versión. Solo quiero que alguien me diga cómo resolverlo. En la publicación anterior de Stackoverflow nadie le dice a la solución.

Versiones: 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

Está utilizando diferentes versiones de JDK para compilar y ejecutar la aplicación . Usted dice que:

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

Así que su compilador (javac) es una versión más nueva que el comando java , lo que significa que el segundo no se puede ejecutar los archivos compilados. Debe utilizar sólo el 1 versión del JDK (lo mismo para java y javac)

Answer 2

En Ubuntu para cambiar la versión de Java tanto para compilar y ejecutar necesite llamar:

sudo update-alternatives --config javac 

y

sudo update-alternatives --config java 

Answer 3

Una mejor solución es cambiar la versión de destino, por lo que puede compilar a 1.6 desde 1.7 como este: How can I set the javac compile version for Play Framework 2.0 to prevent "Unsupported major.minor version"?

Ponga esto en su compilación .cadena:

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