title: Can't export Play! app as war
body: <p>I'm trying to package a Play! app built against Java 7. I'm getting this error. Also, I cannot launch the app from the command line, but from Eclipse it works.</p>
  
  <pre>
  D:\Dropbox\eclipseProjectsClassic>play war MyApp -o MyApp.war --zip
  ~        _            _
  ~  _ __ | | __ _ _  _| |
  ~ | '_ \| |/ _' | || |_|
  ~ |  __/|_|\____|\__ (_)
  ~ |_|            |__/
  ~
  ~ play! 1.2.3, http://www.playframework.org
  ~
  Listening for transport dt_socket at address: 8000
  04:17:03,694 INFO  ~ Starting D:\Dropbox\eclipseProjectsClassic\MyApp
  Exception in thread "main" java.lang.UnsupportedClassVersionError: DocViewerPlugin : Unsupported maj
  or.minor version 51.0
          at java.lang.ClassLoader.defineClass1(Native Method)
          at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
          at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
          at play.classloading.ApplicationClassloader.loadApplicationClass(ApplicationClassloader.java
  :158)
          at play.classloading.ApplicationClassloader.loadClass(ApplicationClassloader.java:84)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
          at play.plugins.PluginCollection.loadPlugins(PluginCollection.java:100)
          at play.Play.init(Play.java:286)
          at play.server.Server.main(Server.java:158)
  
  ~ Packaging current version of the framework and the application to D:\Dropbox\eclipseProjectsClassi
  c\MyApp.war ...
  Traceback (most recent call last):
    File "C:\play\play", line 153, in 
      status = cmdloader.commands[play_command].execute(command=play_command, app=play_app, args=remai
  ning_args, env=play_env, cmdloader=cmdloader)
    File "C:\play\framework\pym\play\commands\war.py", line 65, in execute
      package_as_war(app, env, war_path, war_zip_path, war_exclusion_list)
    File "C:\play\framework\pym\play\utils.py", line 117, in package_as_war
      copy_directory(app.path, os.path.join(war_path, 'WEB-INF/application'), war_exclusion_list)
    File "C:\play\framework\pym\play\utils.py", line 230, in copy_directory
      shutil.copyfile(from_, to_)
    File "C:\play\python\lib\shutil.py", line 53, in copyfile
      fdst = open(dst, 'wb')
  IOError: [Errno 2] No such file or directory: 'D:\\Dropbox\\eclipseProjectsClassic\\MyApp.war\\WEB-
  INF/application\\MyApp.war\\WEB-INF\\application\\MyApp.war\\WEB-INF\\application\\MyApp.war\\WEB
  -INF\\application\\MyApp.war\\WEB-INF\\application\\MyApp.war\\WEB-INF\\application\\test\\data
  \\DataCollectorTest.java'
  
  </pre>
  
  <p><strong>UPDATE</strong> I've solved the UnsupportedClassVersionError by changing the JAVA_HOME system variable to jdk7 directory. The IOError is still coming up though.</p>
  
  <p><strong>UPDATE2</strong> Solved IOError by changing te output directory to "C:\MyApp.war"</p>