java.lang.ClassNotFoundException

[gmeqiminfo]

Hello !

We are look for to use Luaj in our production environments based on tomcat and jboss.
Our POC is this :
We call a lua script in a web application in java 1.6
We used ScriptEngineManager, ScriptEngine to process lua script
In our example, we used commons-lang.jar library added like Web App Librairies (in eclipse)
The basic script which doesn't work is :

String script = "UTILString = luajava.bindClass(\"org.apache.commons.lang.StringUtils\")\n" +
"print( 'UTILString', type(UTILString), UTILString )\n";


When we execute this code in ParserLua.java:

try {
ScriptEngineManager sem = new ScriptEngineManager();
ScriptEngine e = sem.getEngineByName( "luaj" );
ScriptEngineFactory f = e.getFactory();
Bindings scriptBindings = new SimpleBindings();
CompiledScript cs = ((Compilable) e).compile( this.script );
cs.eval( scriptBindings );
} catch (ScriptException e) {
e.printStackTrace();
} catch (LuaError e) {
e.printStackTrace();
}


this code throw this exception:
org.luaj.vm2.LuaError: myscript:4 vm error: java.lang.ClassNotFoundException: ch.hcuge.deja.util.UTILString
at org.luaj.vm2.lib.jse.LuajavaLib.invoke(Unknown Source)
at org.luaj.vm2.lib.VarArgFunction.call(Unknown Source)
at org.luaj.vm2.LuaClosure.execute(Unknown Source)
at org.luaj.vm2.LuaClosure.call(Unknown Source)

the probleme seems to comme from LuajavaLib class :


case BINDCLASS: {
final Class clazz = classForName(args.checkjstring(1));
return JavaClass.forClass(clazz);
}



protected Class classForName(String name) throws ClassNotFoundException {
return Class.forName(name, true, ClassLoader.getSystemClassLoader());
}


=> just the SystemClassLoader is used, and commons-lang is not in !

test in my program before executing cs.eval( scriptBindings ) :

Class c = Class.forName("org.apache.commons.lang.StringUtils", true, ClassLoader.getSystemClassLoader());
=> throw java.lang.ClassNotFoundException

Class c = Class.forName("org.apache.commons.lang.StringUtils", true, this.getClass().getClassLoader());
=>ok

And so, all classes in our framwork lib don't work in a lua script
dao = luajava.newInstance( "ch.xxx.yyy.zzz.dao.DAODocument"); =>throw java.lang.ClassNotFoundException

How can we load from the lua script, user java libraries in a web application?

Thanks for your help.

[gmeqiminfo]

to help someone :

we modifiy LuajavaLib class to add web-app class loader

// load classes using app loader to allow luaj to be used as an extension
protected Class<?> classForName(String name) throws ClassNotFoundException{

    Class<?> c = null;
    try {
        c = Class.forName(name, true, this.getClass().getClassLoader());
    } catch (ClassNotFoundException e) {
        log.error("Attempt to get [" + name + "] from classloader");
    }
    return c;
}