Determining if a class is an event or not
by Edson Tirelli
All,
I reached a point where I need to make a design decision and would like
your opinion about it.
Imagine the following scenario:
A user has a domain model like this:
package a.b.c;
public interface Event { ... }
package x.y.z;
public class MyEvent implements a.b.c.Event {...}
Then, in his DRL file he writes:
package p.q.r;
import event a.b.c.*;
rule X
when
Event( ... )
then
...
end
So, it is clear that a.b.c.Event should be handled as an event by the
engine.
At runtime, the user asserts an object of the class x.y.z.MyEvent into
the working memory. Seems clear to me (and probably to the user) that
MyEvent should be handled as an event, since by DRL semantics, a.b.c.* are
all events, and by OO class hierarchy concept, since a.b.c.Event is an
event, x.y.z.MyEvent is an event too.
My question is: how the engine knows that MyEvent is an event, since it
only has the x.y.z.MyEvent class as input?
The only answer I have is that when the first MyEvent instance is
asserted into the working memory, we must get the class name and iterate
over all event import declarations checking for a match. In case no one is
found, we need to repeat the process for each interface and each class up in
the MyEvent hierarchy. Once this process is complete, we cache the results
in the ObjectTypeConf.
This may be a quite heavy process to be executed each time a fact of a
different class is asserted in the working memory for the first time, but I
can't think a different user-friendly way to solve the question.
The alternatives would be intrusive, IMO, breaking the drools premise to
work with user-defined POJOs as facts: use anotations to annotate classes
that are events, or mandate users implement a specific interface for events.
Any better idea?
[]s
Edson
--
Edson Tirelli
Software Engineer - JBoss Rules Core Developer
Office: +55 11 3529-6000
Mobile: +55 11 9287-5646
JBoss, a division of Red Hat @ www.jboss.com
18 years, 1 month
Drools with j2sdk1.4
by PN Subramanian
Hi,
While going through the manual for Drools 4.0, i came across this
"Drools works with JDK1.5 and above. ..." -
We use j2sdk1.4/j2ee 1.4 in our project - can we use Drools ? Would the
feature set be limited ?
--
P.N.Subramanian
18 years, 1 month
"First CfP of ANSyM 2008: Adaptive Networked Systems and Media"
by nicolae oana
[We apologize in advance if you receive multiple copies of this CFP]
ANSyM2008: Adaptive Networked Systems and Media
------------------------------------------------
June 18-20, 2008, Wroclaw, Poland
http://oxygen.informatik.tu-cottbus.de/ANSyM2008
Special session within the framework of IEA/AIE 2008 conference
http://www.iea-aie.pwr.wroc.pl/
Please submit your paper here:
http://www.iea-aie.pwr.wroc.pl/conftool
Session Organizers
------------------
Dan Popescu, http://automation.ucv.ro/membri/Dan%20Popescu/DPopescu.htm
University of Craiova, Romania, dpopescu(a)automation.ucv.ro
Costin Badica, http://software.ucv.ro/~badica_costin
University of Craiova, Romania, badica_costin(a)software.ucv.ro
Adrian Giurca, http://www.informatik.tu-cottbus.de/~agiurca/
Brandenburg University of Technology, Germany, giurca(a)tu-cottbus.de
Call for Papers
---------------
Adaptability is a generic property of a system that consists in the systems capability to self-adjust its behavior according to its input, load or users in order to meet certain performance criteria. Adaptability has been described as a characteristic of autonomous behavior and is often related to possessing learning capabilities through analysis of past behaviors and interactions. Adaptability has been intensely studied by various areas of engineering including artificial intelligence, control systems and human centered systems. Adaptability has been set as an important requirement for systems devised to work in new generation global networked and distributed environments like wireless networks, P2P networks, Web systems, multi-agent systems, grids, etc. Such systems are expected to pose new challenges for the development and application of adaptation techniques, due to their special characteristics including: interconnectivity, interactivity, distribution, heterogeneity
an
default-tolerance.
This special session welcomes submissions covering all aspects of adaptability in networked systems and media, including (but not limited to):
- Self-configuring and self-structuring systems
- Adaptive control in communication networks
- Adaptive networked control systems
- Rule-based adaptive systems
- Computational intelligence and adaptability
- Adaptability in multi-agent systems
- Personalized and adaptive hypermedia
- Adaptive information provisioning
- Adaptive coordination
- Adaptability in e-services, including e-learning and e-commerce
- Adaptive negotiation
- Context-aware systems
- Machine learning methods for adaptive systems
- Adaptive security systems
Papers acceptance will be judged based on their relevance, clarity of presentation, originality and accuracy of results and proposed solutions.
The papers will be published in the IEA/AIE 2008 conference proceedings, in a bound volume by Springer Verlag in their Lecture Notes in Artificial Intelligence series.
Important dates
---------------
Papers submission: November 15, 2007
Notification of acceptance: February 1, 2008
Final submission: February 28, 2008
Workshop date: To be announced (Inside June 18-20, 2008)
Program Committee
-----------------
Rajendra Akerkar, Technomathematics Research Foundation, India
Steve Banks, University of Sheffield, UK
Dumitru Burdescu, University of Craiova, Romania
Dorian Cojocaru, University of Craiova, Romania
Jens Dietrich, Institute of Information Sciences and Technology, New Zealand
Petr Dostal, Tomas Bata University in Zlin, Czech Republic
Dragan Gasevic, Athabasca University, Canada
Maria Ganzha, Elblag University of Humanities and Economics, Poland
Dariusz Krol, Wroclaw University of Technology, Poland
Ronaldo Menezes, Florida Institute of Technology, USA
Masoud Mohammadian, University of Canberra, Australia
Grzegorz J. Nalepa, AGH University of Science and Technology, Poland
Philippe Trigano, University of Technology of Compiegne, France
Marcin Paprzycki, Systems Research Institute, Polish Academy of Science, Poland
Janusz Sobecki, Wroclaw University of Technology, Poland
Vladimir Rasvan, University of Craiova, Romania
Athanasios Vasilakos, University of Western Macedonia, Greece
Gerd Wagner, Brandenburg University of Technology at Cottbus, Germany
__________________________________________________
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18 years, 1 month
Using JAAS with BRMS on Weblogic
by Harris Trevor
We are using BRMS on Weblogic 9.2 and we want to use JAAS
authentication. We have configured components.xml to include the line:
<security:identity authenticate-method="#{authenticator.authenticate}"
jaas-config-name="myrealm"/>
We get an error message "An error has occurred on the server. See
serverl log for details."
The server log shows
<26-Oct-2007 15:22:32 o'clock BST> <Error> <ServletContext-/drools2>
<000000> <E
xception while dispatching incoming RPC call
java.lang.IllegalArgumentException: No Configuration was registered that
can han
dle the configuration named myrealm
at
com.bea.common.security.jdkutils.JAASConfiguration.getAppConfiguratio
nEntry(JAASConfiguration.java:103)
at
javax.security.auth.login.LoginContext.init(LoginContext.java:243)
at
javax.security.auth.login.LoginContext.<init>(LoginContext.java:367)
at
javax.security.auth.login.LoginContext.<init>(LoginContext.java:444)
at
org.jboss.seam.security.Identity.getLoginContext(Identity.java:313)
Truncated. see log file for complete stacktrace
>
"myrealm" is what weblogic call a security realm is the same as a jaas
configuration name.
Regards Trevor Harris.
18 years, 1 month
