J2Cache示例程序运行报错?报错

运行runtest.bat报错，见下：

>java -Djava.ext.dirs=lib -cp bin net.oschina.j2cache.CacheTester

Exception in thread "main" java.lang.UnsupportedClassVersionError: net/oschina/j
2cache/CacheTester : Unsupported major.minor version 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

windows平台，jdk的版本是1.7
>java -version
java version "1.7.0_67"
Java(TM) SE Runtime Environment (build 1.7.0_67-b01)

Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

不知道j2Cache对jdk的版本要求是哪一个，望各位大神抽点时间回复下，我这个是什么环境问题导致的，不甚感激！