Maven 3.3.9 mvn -version Error:java.lang.UnsupportedClassVersionError

Description

在下载 Maven包，配置了环境变量之后，在命令行执行 mvn -version(or -v) 报错：

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:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
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)

Caused By

JAVA_HOME 中 jdk版本过低。虽然用的是 jdk6，但我下载的 maven 是最新的 3.3.9，把环境变量中的 JAVA_HOME 指向 jdk8，结果正常。

Solution

提高 JAVA_HOME 中 jdk 版本。