在linux centos中执行jar文件

Question

我想在linux中运行一个jar文件但是发生以下错误是什么原因

[root@server ~]# java -jar keygen.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/dgt/jl/App : Unsupported major.minor version 51.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
        at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
Could not find the main class: org.dgt.jl.App. Program will exi

我的java版本：

java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.14) (rhel-1.42.1.11.14.el5_10-i386)
OpenJDK Client VM (build 20.0-b12, mixed mode)

谢谢