Can't resolve JDK issue on Mac

[Mike London]

Hi all,

I've updated Tomcat to version 7, the JDK to version 7, and the run-time to version 7.

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Yet, when I run the application's Servlet (http://localhost:8080/TestServlet/MyServlet), I get this error:

type Exception report

message net/test/servlets/MyServlet : Unsupported major.minor version 51.0 (unable to load class net.test.servlets.MyServlet)

description The server encountered an internal error that prevented it from fulfilling this request.

exception

java.lang.UnsupportedClassVersionError: net/test/servlets/MyServlet : Unsupported major.minor version 51.0

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But, doing a javap -verbose gives me (for this Servlet):

SourceFile: "MyServlet.java"
minor version: 0
major version: 51


***** and, at the command line, "java -version" gives me:

java -version
java version "1.7.0_10"
Java(TM) SE Runtime Environment (build 1.7.0_10-b18)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)

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If I run the project directly from the IDE and it brings up the browser, then it works.

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(Tomcat log has no reported problems.)

I noticed that in "/System/Library/Frameworks/JavaVM.framework", under CurrentVersion it still says 1.6 so that could be the problem, but I don't know how to change that.

I was thinking that installing the latest Java 7 to
"/Library/Java/JavaVirtualMachines/jdk1.7.0_10.jdk" would update the current version.

How do you update the current version "setting" on a Mac in /System/Library/Frameworks/JavaVM.framework (if you need to, that is)? Going into System Preferences already says it's 1.7.0.

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Within the IDE (Intellij IDEA 12) everything is set to Java 7 so I'm really at wits end trying to nail this one down. If I change the Java version to Java 6, then the Servlet loads/works.

What else is there to look at?

Look forward to any suggestions.

Thanks in advance.

- m

[Emanuel Kadziela]

Recompile the java files into new classes using the new JDK.

[Mike London]

Emanuel Kadziela wrote:Recompile the java files into new classes using the new JDK.

Maybe you missed the part of my posting where I said the Servlet...

SourceFile: "MyServlet.java"
minor version: 0
major version: 51

(That's correctly Java 7, so that's not the problem.)

Thanks anyway for your reply.

-Mike

[Bear Bibeault]

Are you running Tomcat standalone, or within the IDE?

[Mike London]

Bear Bibeault wrote:Are you running Tomcat standalone, or within the IDE?

Hi Bear,

Lots of blind alleys....another day shot due to Java configuration Bull****.

In any case, the problem was that I needed to substitute the "New" line below at the top of catalina.sh for what was there. You have to be careful since Tomcat puts another /bin in there for you automatically. Once I realized what was happening in the Echo, it was quickly fixed.

# OLD
# export JAVA_HOME=/Library/Java/Home (Pointed to a 1.6 version of the JDK)

#New - works!
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_10.jdk/Contents/Home

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To answer your question, running it from Intellij worked fine since I suppose it manages things better. The problem happened trying to just run the simple Servlet directly in Tomcat. The JSP was fine, but not the Servlet.

In any case, I just got it working 2 minutes ago and logged back on to post this update in case it might help someone else not spend 7 hours pulling their hair out.

Thanks very much, as always, for your kind reply.

-- Mike

[Bear Bibeault]

Cool, glad that you solved it.

And thanks for reporting back with the solution. Good show!

[Mike London]

Bear Bibeault wrote:Cool, glad that you solved it.

And thanks for reporting back with the solution. Good show!

You bet. Seems like a relatively often occurring problem. Hopefully people will find my post.

Have a good one!

Thanks again.

- Mike