[rules-users] Class loader problem

Hemanth kumar hemanth at saha.in
Tue Nov 3 05:27:13 EST 2009


hi,
Im working on a sample test project.
In that im dynamically creating a class ( fact) and compiling it.

here is my test project
--------------------------------------------------------------------------------------
mainJavaclass


public void runRule()
         {
                 try {
                            System.out.println("\nRunning rule\n");
                               
                                // go !
                                                               
                                URL[] urls = new URL[]{ new
URL("file://"+path) };
                               
                                URLClassLoader ucl =  new
URLClassLoader(urls);
                                Class<?> clazz  =
ucl.loadClass("test.Message");
                                Object classObj = clazz.newInstance();
                               
                               
                                Method method =
clazz.getDeclaredMethod("setMessage", new Class[]{String.class});
                               
                                //System.out.println("facts loaded\n");
               
                                method.invoke(classObj, new
Object[]{"Hello"});
                                                                 
                               
                                log.info("==== Calling Rule Runner ======");
                               
                                Collection facts = new ArrayList();
                                facts.add(classObj);
                               
                               
                                // Load and fire our rules files against the
data
                                new
RuleRunner().runStatelessRules(RULES_FILES, null, facts, null, null,
logger);
                               
                        }
                  catch (Throwable t) {
                                t.printStackTrace();
                        }
                       
         }

----------------------------------------------------------------------
Fact

package test;
public class Message{
private String message;
public String getMessage(){
return this.message;
}

public void setMessage(String message) {
this.message = message;
}

}


------------------------------------------------------------------------
sample rule

package test
import test.Message;

rule "Your First Rule"
     dialect "mvel"
     when
          m:Message(message != "Good Bye"  )
     then
          System.out.println("First Rule fired    "+m.message );
          modify(m){ message = "Good Bye"};
end
-----------------------------------------------------------------
http://old.nabble.com/file/p26160051/console.PNG console.PNG 

what happens is when i was running the project inside eclipse IDE it works
fine but when i hosted in tomcat and calling from outside ide the rule is
not getting fired.
I think the dyanamically loaded class is not recognised by the rule engine.

suggest me any ideas or post an working example

Hemanth
-- 
View this message in context: http://old.nabble.com/Class-loader-problem-tp26160051p26160051.html
Sent from the drools - user mailing list archive at Nabble.com.




More information about the rules-users mailing list