HADOOP部署后运行报错？

RHEL5.8+JRE1.7+HADOOP2.6.5(3.1.0也一样报错后，改用V2.6.5版本)
运行报错如下：

hadoop@hmaster>hadoop fs -help

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/fs/FsShell : 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)

hadoop@hmaster>