Error in running java code in ubuntu

Question

I recently installed the open-jdk 7 in my ubuntu server. But the version is still displayed as :

java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.3) (6b24-1.11.3-1ubuntu0.12.04.1)
OpenJDK Server VM (build 20.0-b12, mixed mode)

And if i try to run a java program i get the foll exception :

Exception in thread "main" java.lang.UnsupportedClassVersionError: hello : Unsupported major.minor version 51.0

Which is the consequence of compiling the program with a higher jdk and trying to run in a lower one. How can i correct this.

Edit:But when i do javac -version I get javac 1.7.0_09 as the response.

There's a javac flag that tells it to compile so it is compatible with lower version. — Krease
– Krease, Commented Jan 6, 2013 at 3:57

Community · Accepted Answer · 2017-04-13 12:22:39Z

1

It sounds like:

1) You have multiple versions of Java installed (which is perfectly OK to do!) ... and ...

2) "javac" is picking up the correct version ... but "java" is picking up a different version.

SOLUTION:

update-java-alternatives

For example, look at this link:

https://askubuntu.com/questions/64329/how-to-replace-openjdk-6-with-openjdk-7

# EXAMPLE:
$ update-java-alternatives -l
java-1.6.0-openjdk 1061 /usr/lib/jvm/java-1.6.0-openjdk
java-1.7.0-openjdk-amd64 1051 /usr/lib/jvm/java-1.7.0-openjdk-amd64
$ sudo update-java-alternatives -s java-1.7.0-openjdk-amd64

edited Apr 13, 2017 at 12:22

CommunityBot

11 silver badge

answered Jan 6, 2013 at 4:10

paulsm4

123k23 gold badges175 silver badges245 bronze badges

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

1 Comment

gautam vegeta Over a year ago

Thanks. Worked like a charm.

hd1 · Accepted Answer · 2013-01-06 03:56:14Z

0

Move the source over and recompile on the ubuntu box?

answered Jan 6, 2013 at 3:56

hd1

34.9k5 gold badges83 silver badges95 bronze badges

1 Comment

gautam vegeta Over a year ago

I did recompile it again but its not working.And how come my jdk version did not change when I installed open-jdk 7. Dosen't version 51.0 indicate that its complied with jdk 7. But when i do javac -version I get javac 1.7.0_09

Icarus · Accepted Answer · 2013-01-06 04:10:52Z

0

Probably the newly installed JDK is in another directory that's not part of your $PATH(very common). I would do a find / -name "javac" and see how many entries are found.

You'll probably find more than one.

answered Jan 6, 2013 at 4:10

Icarus

64k14 gold badges102 silver badges116 bronze badges

Collectives™ on Stack Overflow

Error in running java code in ubuntu

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related