Meta Data Source HELP

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Ciao,
i have a problem with Meta Data Source

I have created 2 snmp data source (both return a Numeric data type)
then i tried to sum these values with a metadata source that return a Numeric data type

return p1.value + p2.value;

but whenever i validate the script, i get a error.

I tried with the example that is descibed in the contextual help

return p1.value;

but don't work :(

What could be the problem?
Can you help me??

What is the error message you get?

Is an "empty" error :(, I don't understand

I attached the snapshot

Attachment: download link

Ah. Can you check the tomcat console for a stack trace?

I attached the section of logcatalina when i tried to check the script

Attachment: download link

What version of Mango are you using?

Assuming you're using 1.8.0, it seems that your environment cannot create a Javascript engine. The null its complaining about is the JS engine itself. What O/S and Java version are you using?

when I installed mango i used the mango-1.8.0.tar.gz packet

Centos release 5.3 (final)
java version 1.6.0

I tried to install the old versions of "Java Runtime Environment":

jre-6u10-xxxxx
jre-6u14-xxxxx
jre-6u17-xxxxx
jre-6u18-xxxxx

but the error continues to exist.

The error, could be caused by tomcat?

What could be the best configuration?

Ciao

Script engines come as part of your java installation. There are a few things you can look for, but probably the easiest thing to do is to run something like this:

    public static void main(String[] args) throws Exception {
        ScriptEngineManager manager = new ScriptEngineManager();
        for (ScriptEngineFactory factory : manager.getEngineFactories()) {
            System.out.println(factory.getEngineName() + " - " + factory.getLanguageName());
        }
    }

This will list out available script engines, at least verifying (or not) the existence of a Javascript engine.

Imports:

import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;

I launched the test

start test .....
...... stop test

there aren't script engines !!!! :(

How must it do?

ciao

Weird. What does it say when you run "java -version"? Confirm that the correct java version is running. You might also check that the rt.jar file contains entries in the com.sun.script package. I've never come across this before, so i'm not sure what the solution is.

Maybe you have a look at the startup script of tomcat /etc/init.c/tomcat*.
They may do things like debian/ubuntu and change the jre/jdk there?

see:http://mango.serotoninsoftware.com/forum/posts/list/331.page
for that thread.

Arne

I found the problem!
Excuse me, but it is my error: i'm new with java!

I have executed the command

java -version

and i have noticed that the version was not the jre1.6.0_17 but jre1.6.0-openjdk: this because when i installed all java world I didn't set the JAVA_HOME variable and it remained the configuration of java of centos distribution (i don't know well the mechanisms of management of Centos related to java ,openJDK).
However, now I have setted JAVA_HOME=/usr/java/latest/ in the script to start tomcat and all work fine!!!

Thanks again, your advices have been very precious!!!

Ciao

peppemath

Glad to hear. Thanks for closing off.