Synchronization error "Unsupported major.minor version 51.0"

[Former Member]

Hello everybody,

Error:

After specifying the Mobilink server to use synchronization scripts I get this error: "Unsupported major.minor version 51.0"

Command to compile:

I wrote the Java code and compile using this command in the command line:

javac -classpath "%SQLANY12%\\java\\mlscript.jar" MobielCMPSynchronization.java

Cause of the problem:

I googled around and find out this has to do with the Java JDK version compatibility problem: "It means that you compiled your classes under a specific JDK, but then try to run them under older version of JDK." I have JDK7 installed and use JDK7 to compile the code. Why does it generate this error, since I don't compile and run against different JDK versions...

Tried the following:

So what I did was I downloaded & installed the older JDK version which is JDK 6.0. In the Eclipse project I specify the JRE to the version 6 (JavaSE-1.6) as the execution environment. So the compiler is using the 1.6 version. I use the command line to run the compile Java classes command.

I'm still getting this error. 😞 Any idea what I can do next... I'm confused now since I have two versions of the JDK now.

[VolkerBarth]

You could use mlsrv12 -sl java with the -jrepath option to specify the right JRE - if it isn't the default one included with SQL Anywhere 12. - Are the settings of JAVA_HOME different?

[Former Member]

What is the default JRE being used by SQLAnywhere 12? How can I check the settings of JAVA_HOME?

[chris_keating]

The other option, if you are not using any JDK1.7 specific features, is to compile with the -target option so that you force it to run against an older JRE.

[VolkerBarth]

From the cited doc:

-jrepath
Override the default JRE path, which is the directory %SQLANY12%\\Sun\\jre160_chip (where chip is a supported chip, such as x86).

For the JAVA_HOME, as with any other environment varible in Windows, check within a cmd window with SET JAVA_HOME, or use the Workplace properties dialogs.

[Former Member]

I have overriden the -jrepath:

mlsrv12 -c "dsn=mobiel-cmp;uid=xxx;pwd=xxx" -x http(host=109.205.192.234;port=3306) -v -sl java (-cp "c:\\Users\\yanling.ch_expericom\\Desktop\\SQLAnywhere db\\synchronization scripts" -jrepath "%SQLANY12%\\Sun\\jre160_x64")

But still getting this error...

[Former Member]

When I compile forcing it to use 1.6 version I get this error:

javac: target release 1.6 conflicts with default source release 1.7

[VolkerBarth]

IMHO, the given command line just sets the JRE to the default one... I would have expected that you set it to your freshly downloaded JRE.

[Former Member · Accepted solution]

Ok, I fixed this problem by removing the 1.7 version in the control panel > remove software.

Compiled the class using -target 1.6 and specified the -jrepath to use "%SQLANY12%Sunjre160_x64" as value when starting the Mobilink server.

[VolkerBarth · Accepted solution]

Just to close this "completely": Does this work without specifying the -jrepath, too?

I would think so as the specified version should be used by default.

[Former Member · Accepted solution]

Yes, it works without specifying the -jrepath.