Cassandra:java.lang.UnsupportedClassVersionError

Question

I had no problem with cassandra but today I tried to install the latest cassandra ver ,after installing cassandra when i tried to run this command:

sudo cassandra -f

it result in this exception:

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/cassandra/service/CassandraDaemon : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
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$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Could not find the main class: org.apache.cassandra.service.CassandraDaemon. Program        will exit.

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java version "1.6.0_27" 
os:ubuntu 12.04 lts

Answer 1

the trunk version of cassandra uses jdk1.7, previous versions use jdk1.6. If you must use jdk1.6 stick with the cassandra-2.0 line (or earlier)