使用 play-scalr 会引发 Unsupported major.minor 版本 51.0

Question

我正在尝试将 play-scalr 与 Play 一起使用，并按照 Github page 上的安装说明进行操作，但是当我请求调整大小的图像时，我收到了错误：

[RuntimeException: java.lang.UnsupportedClassVersionError: se/digiplant/scalr/api/Resizer$Mode : 不支持的major.minor 51.0版]

当我编译项目时，下载了 jar，所以我认为问题在于它们是使用 Java 1.7 编译的，但我正在尝试将它们与 Java 1.6 一起使用：

$ play compile
[info] Loading project definition from /Users/brad/projects/builders/project
[info] Set current project to builders (in build file:/Users/brad/projects/builders/)
[info] Updating {file:/Users/brad/projects/builders/}builders...
[info] downloading http://repo1.maven.org/maven2/se/digiplant/play-scalr_2.10/1.0/play-scalr_2.10-1.0.jar ...
[info]  [SUCCESSFUL ] se.digiplant#play-scalr_2.10;1.0!play-scalr_2.10.jar (2782ms)
[info] downloading http://repo1.maven.org/maven2/se/digiplant/play-res_2.10/1.0/play-res_2.10-1.0.jar ...
[info]  [SUCCESSFUL ] se.digiplant#play-res_2.10;1.0!play-res_2.10.jar (2553ms)
[info] Done updating.
[success] Total time: 26 s, completed 14/04/2013 3:06:18 PM

这是我正在使用的版本：

$ play about
[info] Loading project definition from /Users/brad/projects/builders/project
[info] Set current project to builders (in build file:/Users/brad/projects/builders/)
[info] This is sbt 0.12.2
[info] The current project is {file:/Users/brad/projects/builders/}builders
[info] The current project is built against Scala 2.10.0
[info] Available Plugins: play.Project, sbt.PlayProject, com.typesafe.sbteclipse.plugin.EclipsePlugin, com.typesafe.sbtidea.SbtIdeaPlugin
[info] sbt, sbt plugins, and build definitions are using Scala 2.9.2

$ scala -version
Scala code runner version 2.9.2 -- Copyright 2002-2011, LAMP/EPFL

$ java -version
java version "1.6.0_43"
Java(TM) SE Runtime Environment (build 1.6.0_43-b01-447-11M4203)
Java HotSpot(TM) 64-Bit Server VM (build 20.14-b01-447, mixed mode)

$ javac -version
javac 1.6.0_43

Answer 1

我最终下载了play-scalr 的源代码，使用Java 1.6 进行编译，然后将生成的.jar 放入我的lib/ 目录中。