4:52 p.m.
So I'm playing with Drools in Equinox OSGi, and so far it's behaving quite
nicely - one bit of weirdness though.
What I'm trying to do:
I have a bundle with a 'flow manager' that listens for instances of
WorkItemHandler in the service broker (well, really my own subinterface that
has a getName method). It also listens for new bundles with a
META-INF/drools directory with *.rf files in them, and parses the .rf files
it finds there.
The Flow Manager is itself published as an OSGI Service with a 'perform'
method. It encapsulates all of its Drools calls within the perform method
though - they aren't exposed to clients.
My test involves a simple start->work item->end workflow.
I pass in an instance of a class "Tablex" that can be saved to hibernate. I
also pass in a String that has the table name, and an empty List to get the
results.
My .rf file tries to import Tablex. It declares the three values I mention
above, and maps them to the work item in the work item definition.
<p>
<imports>
<import name="my.pkg.Tablex" />
</imports>
...
<variable name="my.pkg.newrecord" >
<type
name="org.drools.process.core.datatype.impl.type.ObjectDataType"
className="my.pkg.Tablex"/>
</variable>
...
<workItem id="2" name="DBWorkItem" x="165"
y="374" width="80"
height="40" >
<work name="DBWorkItem" >
</work>
<mapping type="in" from="my.pkg.tablename"
to="my.pkg.tablename" />
<mapping type="in" from="my.pkg.newrecord"
to="my.pkg.newrecord"/>
<mapping type="in" from="my.pkg.outlist"
to="my.pkg.outlist"/>
</workItem>
</p>
In my manifest for my .rf file and for the flow manager (where the parsing
occurs) I Import-Package Tablex's package.
When my flow manager tries parsing the rule, it gives an error saying the
the import failed. BUT, everything still works, and my WorkItemHandler works
correctly (the WorkItemHandler imports Tablex itself, since it needs to
manipulate it).
If I declare my Tablex variable as a java.util.Object in the ruleflow then I
don't get the error and things also still work.
If I declare my Tablex as Tablex in the rule flow AND import it in the class
that does the parsing (it's already 'OSGI' imported to the parsing bundle,
but now I'm doing a plain old Java import on it) then everything works fine
with no error message.
Kind of a hybrid question but I figured I'd start with the Drools folks.
Any ideas would be appreciated.
Thanks,
Mike
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5:25 p.m.
Update: The plot thickens.
Sometimes when I'm importing my domain class in the rulesflow, it works, and
sometimes it does not.
This seems to be tied to the class loader that happens to be in the current
thread context. Sometimes it is
org.eclipse.core.runtime.internal.adaptor.ContextFinder and sometimes it is
another type. I don't know what class the 'other type' is because it
overrides Object's toString()and I was just doing
getClassLoader().toString(). I've changed it to
getClassLoader().getClass().getName() so I can see what the real object is
if it happens again
msully wrote:
So I'm playing with Drools in Equinox OSGi, and so far it's behaving quite
nicely - one bit of weirdness though.
What I'm trying to do:
I have a bundle with a 'flow manager' that listens for instances of
WorkItemHandler in the service broker (well, really my own subinterface
that has a getName method). It also listens for new bundles with a
META-INF/drools directory with *.rf files in them, and parses the .rf
files it finds there.
The Flow Manager is itself published as an OSGI Service with a 'perform'
method. It encapsulates all of its Drools calls within the perform method
though - they aren't exposed to clients.
My test involves a simple start->work item->end workflow.
I pass in an instance of a class "Tablex" that can be saved to hibernate.
I also pass in a String that has the table name, and an empty List to get
the results.
My .rf file tries to import Tablex. It declares the three values I
mention above, and maps them to the work item in the work item definition.
<p>
<imports>
<import name="my.pkg.Tablex" />
</imports>
...
<variable name="my.pkg.newrecord" >
<type
name="org.drools.process.core.datatype.impl.type.ObjectDataType"
className="my.pkg.Tablex"/>
</variable>
...
<workItem id="2" name="DBWorkItem" x="165"
y="374" width="80"
height="40" >
<work name="DBWorkItem" >
</work>
<mapping type="in" from="my.pkg.tablename"
to="my.pkg.tablename" />
<mapping type="in" from="my.pkg.newrecord"
to="my.pkg.newrecord"/>
<mapping type="in" from="my.pkg.outlist"
to="my.pkg.outlist"/>
</workItem>
</p>
In my manifest for my .rf file and for the flow manager (where the parsing
occurs) I Import-Package Tablex's package.
When my flow manager tries parsing the rule, it gives an error saying the
the import failed. BUT, everything still works, and my WorkItemHandler
works correctly (the WorkItemHandler imports Tablex itself, since it needs
to manipulate it).
If I declare my Tablex variable as a java.util.Object in the ruleflow then
I don't get the error and things also still work.
If I declare my Tablex as Tablex in the rule flow AND import it in the
class that does the parsing (it's already 'OSGI' imported to the parsing
bundle, but now I'm doing a plain old Java import on it) then everything
works fine with no error message.
Kind of a hybrid question but I figured I'd start with the Drools folks.
Any ideas would be appreciated.
Thanks,
Mike
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5:29 p.m.
Here's the ClassLoader that let's the import work:
org.springframework.osgi.util.BundleDelegatingClassLoader
OK, I realize this is starting to seem like a question for another board,
but I figured I'd put all the info here since I started here.
If I find the solution elsewhere, I'll share here.
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6:47 a.m.
Let me start by saying that I am unfamiliar with Drools Flow but I
encountered a similar issue when using Drools Expert in Eclipse, which is
due to the ClassLoader behavior defined by OSGi v4. Drools attempts to
access a Class through a reference to a ClassLoader, which by default is its
bundle ClassLoader. MVEL attempts to access a Class through the context
ClassLoader, which OSGi sets to the bundle's ClassLoader. The problem arises
because neither the Drools bundle nor the MVEL bundle (I have each Drools
artifact in a separate bundle) declare a dependency on the package
containing your classes. Therefore, OSGi does not add that package to the
bundle's ClassLoader and you get a ClassNotFoundException when Drools
attempts to find the Class.
I worked around this issue by doing several things:
1) Created an implementation of ClassLoader that delegates to the bundle
(BundleClassLoader).
2) Created a composite ClassLoader that contains many bundle ClassLoaders
(CompositeClassLoader).
3) For each bundle containing a rule or fact, wrap it in a BundleClassLoader
and add it to the CompositeClassLoader.
4) Pass the CompositeClassLoader to Drools when creating the
KnowledgeBuilder.
5) Wrap the Drools facades in a Class that sets the context ClassLoader
before each method invocation and restores the original context ClassLoader
afterwards.
This takes care of most but not all of the issues. Specifically, some
invocations of MVEL still fail but the system works. Unfortunately, I have
trouble consistently reproducing the issue so I have been unable to track it
down. It may no longer exist in the latest Drools; I encountered this issue
in the M3 build last December.
I have included my implementation of BundleClassLoader below as well as an
example of a wrapper method:
@Override
public ProcessInstance startProcess(final String processId, final
Map<String, Object> parameters) {
ClassLoader old = Thread.currentThread().getContextClassLoader();
try {
Thread.currentThread().setContextClassLoader(getEngineClassLoader());
return super.startProcess(processId, parameters);
} finally {
Thread.currentThread().setContextClassLoader(old);
}
}
The getEngineClassLoader() method returns the CompositeClassLoader, which I
built in the Activator.
----------------------------------------------------------------------------
----------------------------------
/**
* Wraps a Bundle; making it appear as a ClassLoader.
* <p/>
* This is an adaptation of the technique described in the article <i>
* <a href='http://wiki.eclipse.org/BundleProxyClassLoader_recipe'>
* BundleProxyClassLoader recipe</a></i>. The main changes were to add
* comments and declarations for generic types.
*
* @author Simon Kaegi
* @author Faron Dutton
*/
public class BundleProxyClassLoader extends ClassLoader implements
DroolsClassLoader {
private final Bundle bundle;
/**
* Initializes a new instance of this class.
*
* @param bundle the bundle to wrap
* @throws IllegalArgumentException if bundle is <code>null</code>
*/
public BundleProxyClassLoader(final Bundle bundle) {
this(bundle, null);
}
/**
* Initializes a new instance of this class.
*
* @param bundle the bundle to wrap
* @param parent the parent class loader. may be <code>null</code>
* @throws IllegalArgumentException if bundle is <code>null</code>
*/
public BundleProxyClassLoader(final Bundle bundle, final ClassLoader
parent) {
super(parent);
this.bundle = bundle;
if (this.bundle == null) {
throw new IllegalArgumentException("bundle cannot be null");
}
}
/* (non-Javadoc)
* Both ClassLoader.getResources(...) and bundle.getResources(...)
* consult the boot class loader. As a result, BundleProxyClassLoader.
* getResources(...) might return duplicate results from the boot
* class loader. Prior to Java 5 Classloader.getResources was marked
* final. If your target environment requires at least Java 5 you
* can prevent the occurrence of duplicate boot class loader resources
* by overriding ClassLoader.getResources(...) instead of
* ClassLoader.findResources(...).
*
* @see java.lang.ClassLoader#findResources(java.lang.String)
*/
@SuppressWarnings("unchecked")
protected Enumeration<URL> findResources(final String name) throws
IOException {
return bundle.getResources(name);
}
/* (non-Javadoc)
* @see java.lang.ClassLoader#findResource(java.lang.String)
*/
protected URL findResource(final String name) {
return bundle.getResource(name);
}
/* (non-Javadoc)
* @see java.lang.ClassLoader#findClass(java.lang.String)
*/
protected Class<?> findClass(final String name) throws
ClassNotFoundException {
return bundle.loadClass(name);
}
/* (non-Javadoc)
* @see java.lang.ClassLoader#getResource(java.lang.String)
*/
public URL getResource(final String name) {
return (getParent() == null) ? findResource(name) :
super.getResource(name);
}
/* (non-Javadoc)
* @see java.lang.ClassLoader#loadClass(java.lang.String, boolean)
*/
@Override
public synchronized Class<?> loadClass(final String name, final boolean
resolve) throws ClassNotFoundException {
Class<?> clazz = (getParent() == null) ? findClass(name) :
super.loadClass(name, false);
if (resolve) {
super.resolveClass(clazz);
}
return clazz;
}
/* (non-Javadoc)
* @see
org.drools.rule.DroolsClassLoader#fastFindClass(java.lang.String)
*/
public Class<?> fastFindClass(final String name) {
try {
return bundle.loadClass(name);
} catch (ClassNotFoundException e) {
return null;
}
}
}
9:57 a.m.
Thanks - I started to try something like this, but I found that Drools
Package Builder was using its class classloader for the context - so I
started to override it but Eclipse isn't letting me import PackageBuilder
into my java class.
When I tried getting drools working in OSGI, I found that several different
jars had the same package. The only way I know to get OSGi to resolve this
is to make some of the jars fragments against the remaining one. But when I
do this, Eclipse lets me import-package the package I need to inherit from
in the manifest builder, but it doesn't let me do the import in the Java
editor.
Did you encounter the package issue with the jars? Is there a better way to
solve that?
Thanks,
mike
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12:04 p.m.
New subject: OSGI, classloading, and imports in KnowledgeBuilder
The only way that I have found that works is using Require-Bundle instead
of Import-Package. This ensures that you can see all the classes in
a 'split' package.
1:26 p.m.
New subject: OSGI, classloading, and imports in KnowledgeBuilder
fgdutton(a)gmail.com wrote:
The only way that I have found that works is using Require-Bundle
instead of Import-Package. This ensures that you can see all the
classes in a 'split' package.
If someone is willing to work with us, we
will do all the necessary
changes to get everything working properly out of the box. but we do
need this as a community effort, as we are stretched everywhere else.
Mark
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10:21 a.m.
Faron - I think I fixed my problem (and without the PackageBuilder stuff) but
I think I cheated :)
In my BundleListener, when I find a Bundle with an .rf file I want to
compile, I do this:
Create an instance of a new Classloader that first delegates class loading
to my BundleListener's Bundle, and if that fails, delegates to the .rf files
Bundle. I pass this class loader in using a KnowledgeBuilderConfiguration.
BundleClassLoader bclassLoader = new
BundleClassLoader(bundleContext.getBundle(), bundle);
KnowledgeBuilderConfiguration conf =
KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
bclassLoader);
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder(conf);
The Classloader looks much like yours, but each overridden call looks like:
protected Class<?> findClass(final String name) throws
ClassNotFoundException {
try {
Class<?> clazz = primeBundle.loadClass(name);
return clazz;
} catch (ClassNotFoundException c) {
if (secondBundle != null) {
Class<?> clazz2 = secondBundle.loadClass(name);
return clazz2;
} else {
logger.info("Second is null");
throw c;
}
}
}
Now only my bundles containing rules need to import the classes they need -
my bundle containing the 'FlowManager' that wraps the call to perform does
not. It allows my core Flow bundle to be totally agnostic to the data
processed in it, while its clients, WorkItemHandlers and flow definition
bundles only import the classes they need. Hopefully this is a lasting
solution - my Drools usage isn't very complex right now.
I imagine I'd have to get a little more complex if I were to use any
abilities where Drools had to create instances of my domain objects at
process time, but right now that is all handled by WorkItemHandlers that are
registered as services from their own bundles.
Mark - I'd love to help, but I'm just starting with Drools and OSGi right
now, so I'm not sure I know enough yet.
Mike
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3:29 a.m.
[...] Therefore, OSGi does not add that package to the
bundle's ClassLoader and you get a ClassNotFoundException when Drools
attempts to find the Class.
Even when adding the Drools runtime jars in the bundle using them I run
into problems.
When using Drools (version 5.0.1) from within an OSGi context the
NoClassDefFoundError seems unavoidable. The really strange thing is that
the error is triggered by drools itself and in an attempt to access a
class from within the very same jar file. Have a look at the foolowing
stacktrace:
java.lang.NoClassDefFoundError:
org/drools/base/extractors/BaseObjectClassFieldReader
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at
org.drools.base.ClassFieldAccessorCache$ByteArrayClassLoader.defineClass(ClassFieldAccessorCache.java:367)
at
org.drools.base.ClassFieldAccessorFactory.getClassFieldReader(ClassFieldAccessorFactory.java:135)
at
org.drools.base.ClassFieldAccessorCache$CacheEntry.getReadAccessor(ClassFieldAccessorCache.java:315)
at
org.drools.base.ClassFieldAccessorCache.getReadAcessor(ClassFieldAccessorCache.java:245)
at
org.drools.base.ClassFieldAccessorStore.wire(ClassFieldAccessorStore.java:379)
at
org.drools.base.ClassFieldAccessorStore.getReader(ClassFieldAccessorStore.java:97)
at
org.drools.base.ClassFieldAccessorStore.getReader(ClassFieldAccessorStore.java:74)
at
org.drools.rule.builder.PatternBuilder.getFieldReadAccessor(PatternBuilder.java:1031)
at
org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:326)
at
org.drools.rule.builder.PatternBuilder.buildConstraint(PatternBuilder.java:239)
at
org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:196)
at
org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:104)
at
org.drools.rule.builder.GroupElementBuilder.build(GroupElementBuilder.java:69)
at org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:68)
at
org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:1159)
at
org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:649)
at
org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:278)
at
org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:510)
at
org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:31)
at
com.apc.config.configurator.rules.decisiontable.DecisionTableHelper.<init>(DecisionTableHelper.java:53)
The actual Drools code is a simple use of a DecisionTable:
public DecisionTableHelper(String path) {
DecisionTableConfiguration dtableconfiguration =
KnowledgeBuilderFactory.newDecisionTableConfiguration();
dtableconfiguration.setInputType(DecisionTableInputType.XLS);
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
Resource pathResource = ResourceFactory.newClassPathResource(path,
getClass());
kbuilder.add(pathResource, ResourceType.DTABLE,
dtableconfiguration);
if ( kbuilder.hasErrors() ) {
System.err.print( kbuilder.getErrors() );
return;
}
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages( kbuilder.getKnowledgePackages() );
ksession = kbase.newStatelessKnowledgeSession();
}
As seen from the stack trace the problem occurs when adding the resource
to the KnowledgeBuilder.
Originally I attempted to created a Drools 5.0.1 OSGi bundle that I could
just add to the Eclipse targetplatform. However – as a result of the above
described issue – the setup is now reduced to adding the Drools runtime
jars directly to the bundle in which they are to be used. The problem
remains.
I have read Faron Duttons post regarding the ClassLoader behavior of OSGi.
I have added the BundleProxyClassLoader from the post and tried creating a
KnowledgeBuilderConfiguration based on this ClassLoader. It seems however
that the problem remains as the ByteArrayClassLoader (where the issue is
triggerd) does not use the ClassLoader specified in the
KnowledgeBuilderConfiguration.
Can anyone sketch a setup so that I can use Drools from within an Eclipse
plugin?
/Lasse
4:22 a.m.
Can anyone sketch a setup so that I can use Drools from within an
Eclipse
plugin?
I've got it running. You need to make sure your classloaders are the
right ones.
I use the
new PackageBuilderConfiguration(Classloader, Properties)
ctor (if you're setting CL later, Properties may fail to apply) and
new RuleBaseConfiguration(Classloader)
respectively. I guess the knowledge-based apis have matching ctors. I
use the classloader of my project, which imports the needed drools
namespaces. That last part may need some time, but I's doable.
Cheers,
Simon
6:03 a.m.
> Can anyone sketch a setup so that I can use Drools from within
an
Eclipse
> plugin?
I've got it running. You need to make sure your classloaders are the
right ones.
I use the
new PackageBuilderConfiguration(Classloader, Properties)
ctor (if you're setting CL later, Properties may fail to apply) and
new RuleBaseConfiguration(Classloader)
respectively. I guess the knowledge-based apis have matching ctors. I
use the classloader of my project, which imports the needed drools
namespaces. That last part may need some time, but I's doable.
I have tried the following:
KnowledgeBuilderConfiguration builderConfiguration =
KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
getClass().getClassLoader());
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder(builderConfiguration);
Resource pathResource = ResourceFactory.newClassPathResource(path,
getClass());
kbuilder.add(pathResource, ResourceType.DTABLE, dtableconfiguration);
However it still fails ...
Does this compare to what you are doing? Are you able to do DecisionTables
as well?
regards
Lasse
7:39 a.m.
Lasse.Wallentin(a)apcc.com wrote:
>> Can anyone sketch a setup so that I can use Drools from
within an
Eclipse
>> plugin?
> I've got it running. You need to make sure your classloaders are the
> right ones.
> I use the
> new PackageBuilderConfiguration(Classloader, Properties)
>
> ctor (if you're setting CL later, Properties may fail to apply) and
>
> new RuleBaseConfiguration(Classloader)
>
> respectively. I guess the knowledge-based apis have matching ctors. I
> use the classloader of my project, which imports the needed drools
> namespaces. That last part may need some time, but I's doable.
>
I have tried the following:
KnowledgeBuilderConfiguration builderConfiguration =
KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
getClass().getClassLoader());
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder(builderConfiguration);
Resource pathResource = ResourceFactory.newClassPathResource(path,
getClass());
kbuilder.add(pathResource, ResourceType.DTABLE, dtableconfiguration);
However it still fails ...
Does this compare to what you are doing? Are you able to do DecisionTables
as well?
Roughly; I use neither knowledge API nor tables. However I guess
you're
not importing org.drools.base.extractors, so your classloader won't let
drools load that class. There was a heap of drools stuff I've never
heard of but had to import before it worked.
HTH,
Simon
9:09 a.m.
Lasse Wallentin | APC by Schneider Electric | Senior Software
Developer
Phone: ++45 72 190 134 | Mobile: ++45 41 37 7974
Email: lasse.wallentin(a)apc.com | Address: Silcon Allé 1, DK-6000
Kolding
*** Please consider the environment before printing this e-mail
rules-users-bounces(a)lists.jboss.org wrote on 12-08-2009 14:39:12:
Lasse.Wallentin(a)apcc.com wrote:
>>> Can anyone sketch a setup so that I can use Drools from within an
> Eclipse
>>> plugin?
>> I've got it running. You need to make sure your classloaders are the
>> right ones.
>> I use the
>> new PackageBuilderConfiguration(Classloader, Properties)
>>
>> ctor (if you're setting CL later, Properties may fail to apply) and
>>
>> new RuleBaseConfiguration(Classloader)
>>
>> respectively. I guess the knowledge-based apis have matching ctors. I
>> use the classloader of my project, which imports the needed drools
>> namespaces. That last part may need some time, but I's doable.
>>
>
> I have tried the following:
>
> KnowledgeBuilderConfiguration builderConfiguration =
> KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
> getClass().getClassLoader());
> KnowledgeBuilder kbuilder =
> KnowledgeBuilderFactory.newKnowledgeBuilder(builderConfiguration);
> Resource pathResource = ResourceFactory.newClassPathResource(path,
> getClass());
> kbuilder.add(pathResource, ResourceType.DTABLE, dtableconfiguration);
>
> However it still fails ...
>
> Does this compare to what you are doing? Are you able to do
DecisionTables
> as well?
Roughly; I use neither knowledge API nor tables. However I guess you're
not importing org.drools.base.extractors, so your classloader won't let
drools load that class. There was a heap of drools stuff I've never
heard of but had to import before it worked.
I have tried importing all packages this does not change anything.
/Lasse
3:30 p.m.
I have tried the following:
KnowledgeBuilderConfiguration builderConfiguration =
KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
getClass().getClassLoader());
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder(builderConfiguration);
Resource pathResource = ResourceFactory.newClassPathResource(path,
getClass());
kbuilder.add(pathResource, ResourceType.DTABLE, dtableconfiguration);
However it still fails ...
Does this compare to what you are doing? Are you able to do
DecisionTables
as well?
Ok, I finally got it running. I had missed an import in the excel sheet so
I had a dependency on another bundle.
All this debugging has made me understand (and appreciate) the solution
sketched earlier by Faron Dutton more clearly. However it still seems a
bit involved when just a few decisiontables is needed - don't you think?
regards
Lasse
12:17 p.m.
Lasse.Wallentin(a)apcc.com wrote:
Ok, I finally got it running. I had missed an import in the excel
sheet so
I had a dependency on another bundle.
Cool!
All this debugging has made me understand (and appreciate) the
solution
sketched earlier by Faron Dutton more clearly. However it still seems a
bit involved when just a few decisiontables is needed - don't you think?
I
think that under OSGi in gereral, the classloader becomes much more
important. Luckily drools is prepared for that, but it still pushes OSGi
a fair bit - with us witnessing the fallout.
Basically you need a classloader which can access you classes _and_ all
drools internals. Probably we could combine them somehow. Thought,
googled :)
http://www.osgi.org/blog/2008/08/classy-solutions-to-tricky-proxies.html
I'm not too content with my setup as well, maybe you can sketch yours as
it's running now? I'm gonna the try above solution, maybe we can
establish some best practise.
Cheers,
Simon
8:13 p.m.
We'd really like to improve out OSGi friendlyness. From getting Drools
to work perfectly as an OSGi service, to getting our build system to
publish all the necessary bundles. But we need people in the commnity to
help us, you know where to find us if you want to help out, as we have
so much other core stuff to do :)
http://wwws.jboss.org/drools/irc.html
Mark
Simon Thum wrote:
Lasse.Wallentin(a)apcc.com wrote:
> Ok, I finally got it running. I had missed an import in the excel sheet so
> I had a dependency on another bundle.
>
Cool!
> All this debugging has made me understand (and appreciate) the solution
> sketched earlier by Faron Dutton more clearly. However it still seems a
> bit involved when just a few decisiontables is needed - don't you think?
>
I think that under OSGi in gereral, the classloader becomes much more
important. Luckily drools is prepared for that, but it still pushes OSGi
a fair bit - with us witnessing the fallout.
Basically you need a classloader which can access you classes _and_ all
drools internals. Probably we could combine them somehow. Thought,
googled :)
http://www.osgi.org/blog/2008/08/classy-solutions-to-tricky-proxies.html
I'm not too content with my setup as well, maybe you can sketch yours as
it's running now? I'm gonna the try above solution, maybe we can
establish some best practise.
Cheers,
Simon
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1:40 a.m.
Mark Proctor <mproctor(a)codehaus.org> wrote on 14-08-2009 03:13:42:
We'd really like to improve out OSGi friendlyness. From getting
Drools to work perfectly as an OSGi service, to getting our build
system to publish all the necessary bundles. But we need people in
the commnity to help us, you know where to find us if you want to
help out, as we have so much other core stuff to do :)
http://wwws.jboss.org/drools/irc.html
I would love to help out on this issue - I'll put in on my TODO list ;-)
/Lasse
4:06 a.m.
Lasse.Wallentin(a)apcc.com schrieb:
Mark Proctor <mproctor(a)codehaus.org> wrote on 14-08-2009
03:13:42:
> We'd really like to improve out OSGi friendlyness. From getting
> Drools to work perfectly as an OSGi service, to getting our build
> system to publish all the necessary bundles. But we need people in
> the commnity to help us, you know where to find us if you want to
> help out, as we have so much other core stuff to do :)
> http://wwws.jboss.org/drools/irc.html
>
I would love to help out on this issue - I'll put in on my TODO list ;-)
/Lasse
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I would also love to help - it's on my TODO list, too ;-)
--
ekke (ekkehard gentz)
independent software-architect
senior erp-consultant
eclipse | osgi | equinox | mdsd | oaw | emf | uml
max-josefs-platz 30, D-83022 rosenheim, germany
mailto:ekke@ekkes-corner.org
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twitter: @ekkescorner
skype: ekkes-corner
Steuer-Nr: 156/220/30931 FA Rosenheim, UST-ID: DE189929490
11:15 a.m.
New subject: build from svn - report
Hi,
I am trying to build latest source from svn, in order to try new rulesflow features. I am
following instructions provided in README.txt
I have maven 2.0.9 and execute:
mvn -Declipse -Ddocumentation clean install
-DlocalEclipseDrop=C:/Users/agaton/tools
It seems that it does not work with jdk 1.5.0_16 and Windows Vista Business SP2.
[INFO] [compiler:compile]
[INFO] Compiling 339 source files to
C:\Users\agaton\projects\jbossrules\drools-compiler\target\classes
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure
Failure executing javac, but could not parse the error:
The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
at com.sun.tools.javac.jvm.Items.makeLocalItem(Items.java:111)
at com.sun.tools.javac.jvm.Gen.visitIdent(Gen.java:2066)
at com.sun.tools.javac.tree.Tree$Ident.accept(Tree.java:1003)
at com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:811)
at com.sun.tools.javac.jvm.Gen.visitBinary(Gen.java:1906)
at com.sun.tools.javac.tree.Tree$Binary.accept(Tree.java:926)
Then, if I switch JAVA_HOME to jdk1.6.0_14
I see two errors in tests:
Tests in error:
testUnmarshallingPerformance(org.drools.integrationtests.LargeRuleBaseSerializationTest)
testUnmarshallWithCompressionPerformance(org.drools.integrationtests.LargeRuleBaseSerializationTest)
Tests run: 1244, Failures: 0, Errors: 2, Skipped: 1
Then, I tried to run second command:
mvn -Ddocumentation -Declipse -DskipTests package javadoc:javadoc assembly:assembly
-DlocalEclipseDrop=C:/Users/agaton/tools/jboss-tools
with:
set MAVEN_OPTS=-Xmx512m
but the maven hangs on one javadoc.
with:
set MAVEN_OPTS=-Xmx1024m
it works ok
best,
Milan
Send instant messages to your online friends http://uk.messenger.yahoo.com
3:50 p.m.
Mark Proctor wrote:
We'd really like to improve out OSGi friendlyness. From getting
Drools
to work perfectly as an OSGi service, to getting our build system to
publish all the necessary bundles. But we need people in the commnity to
help us, you know where to find us if you want to help out, as we have
so much other core stuff to do :)
http://wwws.jboss.org/drools/irc.html
Good to know; I've got some bits up my
sleeves.
FTR, the chained classloader approach forked fine for me, though I can't
recommend the one in the osgi blog article (it doesn't maintain order).
It allow drools usage without overgrown imports. You'll have to knock up
some trivial chained classloader though, but if you're in osgi this
seems to have utility anyway.
Mark
Simon Thum wrote:
> Lasse.Wallentin(a)apcc.com wrote:
>
>> Ok, I finally got it running. I had missed an import in the excel
>> sheet so I had a dependency on another bundle.
>>
> Cool!
>
>
>> All this debugging has made me understand (and appreciate) the
>> solution sketched earlier by Faron Dutton more clearly. However it
>> still seems a bit involved when just a few decisiontables is needed -
>> don't you think?
>>
> I think that under OSGi in gereral, the classloader becomes much more
> important. Luckily drools is prepared for that, but it still pushes OSGi
> a fair bit - with us witnessing the fallout.
>
> Basically you need a classloader which can access you classes _and_ all
> drools internals. Probably we could combine them somehow. Thought,
> googled :)
> http://www.osgi.org/blog/2008/08/classy-solutions-to-tricky-proxies.html
>
> I'm not too content with my setup as well, maybe you can sketch yours as
> it's running now? I'm gonna the try above solution, maybe we can
> establish some best practise.
>
> Cheers,
>
> Simon
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
------------------------------------------------------------------------
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5:34 p.m.
Hi Lasse,
I'm running into the exact same problem as you did. I have an OSGI bundle
where I embed Drools and all the dependencies and I'm deploying it on FUSE
4.0 . I tried passing the classloader posted on this thread to Drools but
still the same problem. I don't understand when you talk about the imports
where they should be placed and which imports.
I'm kind of desperate since I have a deadline next week and I don't know
what else to try. I will appreciate a lot if you could give me some help on
get this working like posting some code about your solution.
KnowledgeBuilderConfiguration builderConfiguration =
KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(null,
getClass().getClassLoader());
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder(builderConfiguration);
Resource pathResource = ResourceFactory.newClassPathResource(path,
getClass());
kbuilder.add(pathResource, ResourceType.DTABLE, dtableconfiguration);
However it still fails ...
Does this compare to what you are doing? Are you able to do
DecisionTables
as well?
Ok, I finally got it running. I had missed an import in the excel
sheet so
I had a dependency on another bundle.
Thanks in advance,
-Marcel
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Sent from the drools - user mailing list archive at Nabble.com.
7:16 a.m.
Hi Marcel,
I'm running into the exact same problem as you did. I have an
OSGI
bundle
where I embed Drools and all the dependencies and I'm deploying
it on
FUSE
4.0 . I tried passing the classloader posted on this thread to Drools
but
still the same problem. I don't understand when you talk about
the
imports
where they should be placed and which imports.
The imports I was talking about was the ones embeded in the Descision
tables.
Depending on your spreadsheet editor the imports may have a tendency to
hide themselves ;-(
A neat trick when working with Decision Tables is to convert them to the
rule format.
Something like the below lines will achieve this:
public String compile(String path) {
String drlStr = "";
try {
Resource pathResource =
ResourceFactory.newClassPathResource(path, getClass());
DecisionTableConfiguration dtableconfiguration =
KnowledgeBuilderFactory.newDecisionTableConfiguration();
dtableconfiguration.setInputType(DecisionTableInputType.XLS);
drlStr =
DecisionTableFactory.loadFromInputStream(pathResource.getInputStream(),
dtableconfiguration);
} catch (IOException e) {
e.printStackTrace();
}
return drlStr;
}
Kind regards
Lasse Wallentin
5559
days inactive
5637
days old
21 comments
9 participants
participants (9)
-
Clandes Tino -
ekke -
Faron Dutton -
fgdutton＠gmail.com
-
Lasse.Wallentin＠APCC.com -
Marcel Casado -
Mark Proctor -
msully -
Simon Thum