org/apache/ma ven/cli/MavenCli : Unsupported major.minor version 51.0

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/ma
ven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:14
1)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(Cl
assRealm.java:401)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(
SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadCl
ass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm
.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm
.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launch
er.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Laun
cher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.jav
a:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(La
uncher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:
356)

究其原因呢，就是我的java版本太低了，maven版本太高导致的。高版本的Java编译的maven,运行在了低版本的Java上就会出现这样的问题。

知道问题所在就好对症下药了，我有两种方案：一种是升级java版本，一种就是重新下载低版本的maven了。

我由maven3.3.3换成了maven3.0.5，后命令成功执行。

C:\Users\Administrator>mvn -version
Apache Maven 3.0.5 (r01de14724cdef164cd33c7c8c2fe155faf9602da; 2013-02-19 21:51:
28+0800)
Maven home: D:\apache-maven-3.0.5\bin\..
Java version: 1.6.0_43, vendor: Sun Microsystems Inc.
Java home: D:\Program Files (x86)\Java\jdk1.6.0_43\jre
Default locale: zh_CN, platform encoding: GBK
OS name: "windows 7", version: "6.1", arch: "x86", family: "windows"