java - Maven Installation OSX Error Unsupported major.minor version 51.0

Question

I installed maven by following this steps:(a tutorial)

JAVA_HOME=/Library/Java/Home
export M2_HOME=/Users/steven/zimmermann/maven
export M2=$M2_HOME/bin
export PATH=$M2:$PATH

echo $JAVA_HOME
echo $M2_HOME
echo $M2
echo $PATH

nano .bash_profile

then I wrote the echo in the .bash_profile sth like this:

JAVA_HOME=/usr/libexec/java_home
M2_HOME=/path/to/your/apache-maven-3.x.x
M2=/path/to/your/apache-maven-3.x.x/bin
PATH=/path/to/maven/bin:/$….bla-bla-bla…

and also I wrote this in the .bashrc

export M2_HOME=/Users/steven/zimmermann/maven
export M2=$M2_HOME/bin
export PATH=$M2:$PATH

now when I want to check the version (mvn -v) I get the following exception: I think there are some versions wrong, but I don't know.

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    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(ClassRealm.java:401)
    at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(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(Launcher.java:144)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)

Additional information:

java -version

java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

javac -version

javac 1.8.0_40

Answer 1

The problem is because you haven't set JAVA_HOME in Mac properly. In order to do that, you should do set it like this:

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home

In my case my JDK installation is jdk1.8.0_40, make sure you type yours.

Then you can use maven commands.

Regards!