java.lang.UnsupportedClassVersionError: exception while installing java 1.6 with 1.7 already installed?

Question

I have got java 1.7 already installed in my computer(Ubuntu 12.04) and with Java_Home and path properly set.Now I want to install java 1.6 as well because one application I want to use runs only with java1.6.

Here is what I have done so far,
1: I download jdk1.6 and extracted it.
2: Modified the java_home and path to include to point to jdk 1.6.
3: Ran these update-alternative commands

sudo update-alternatives --set java /usr/local/java/jdk1.6.0_45/bin/java
sudo update-alternatives --set javac /usr/local/java/jdk1.6.0_20/bin/javac

Now when I do java -version, I see correct version and I can also compile properly but I do java className I get the following error

Exception in thread "main" java.lang.UnsupportedClassVersionError: three : 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: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)

My path variable looks like this

/usr/local/bin:/usr/bin:/bin:/usr/games:/usr/local/java/jdk1.7.0_40/bin:/usr/local/java/jre1.7.0_40/bin:/usr/local/java/jdk1.6.0_45/bin:/usr/local/java/jdk1.6.0_45/bin

I read somewhere that if java 1.7 comes before 1.6 in path, there will be a conflict. Could that be the case? In that case,how to remove that from path variable?

Milad Qasemi · Accepted Answer · 2014-11-15 14:20:54Z

1

you have both jdk 1.6 and 1.7 in your path remove the older version from the path

answered Nov 15, 2014 at 14:20

Milad Qasemi

3,0593 gold badges15 silver badges17 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Sahil Over a year ago

how do I remove it from path? I just add path in .profile. Also can't I have two java version installed?

Milad Qasemi Over a year ago

if this /home/wrong/dir/ is the directory you want to delete do this PATH=echo $PATH | sed -e 's/:\/home\/wrong\/dir\/$//'

Sahil Over a year ago

why did you put a $ in sed?

Collectives™ on Stack Overflow

java.lang.UnsupportedClassVersionError: exception while installing java 1.6 with 1.7 already installed?

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related