[rules-users] Drools fusion how to I catch an Exception

[Wolfgang Laun]

Works for me, i.e., the DRL compiler flags an error.
Checked with 5.2.0, 5.3.0, 5.4.0.
-W


On 05/09/2012, RichardAmbridge <richard.ambridge at gmail.com> wrote:
> If I have a rule that has an error in it, the error isn't being caught by
> the
> compiler and the error doesn't happen as the Object is inserted into the
> session, it only happens after a time period completes, then Drools
> silently
> fails.
> How can I catch these silent failures.
>
> See below for test case.
>
> Notice in the After5 rule there is a mistake in the then part.
> m.status=$m.status;
>
> $m doesn't exist.
>
> If i change this to $m.status=m.status, the compiler detects the error, but
> this way of m.status=$m.status is not found.
>
> When the rule fires it just dies.
> I need to be able to catch the Exception somehow and report it..
>
> Any help really appreciated..
> Thanks
> Ric
>
>
> ----------
> sample.drl:-
> ----------
>
> package com.sample
>
> import com.sample.DroolsTest.Message;
>
> declare Message
>  @role ( event )
> end
> rule "Hello"
>  dialect "mvel"
>
> 	when
> 		m : Message( status == Message.HELLO, myMessage : message )		
> 		
> 	then
> 		System.out.println( "Hello added" );		
> end
>
> rule "After5"
>  dialect "mvel"
>
> 	when
> 		m : Message( status == Message.HELLO, myMessage : message )
> 		not( Message( status == Message.GOODBYE , this after [0s,5s] m ))
> 		
> 	then
> 		System.out.println( "After5 then start" );
> 		m.status=$m.status;
> 		System.out.println( "After5 then stop" );
> 		retract(m);
> end
>
> ----------
> DroolsTest.java:
> ----------
> package com.sample;
>
> import org.drools.KnowledgeBase;
>
> /**
>  * This is a sample class to launch a rule.
>  */
> public class DroolsTest {
>
> 	public static final void main(String[] args) {
> 		try {
> 			// load up the knowledge base
> 			KnowledgeBase kbase = readKnowledgeBase();
> 			StatefulKnowledgeSession ksession = kbase
> 					.newStatefulKnowledgeSession();
> 			KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory
> 					.newFileLogger(ksession, "test");
> 			// go !
> 			Message message = new Message();
> 			message.setMessage("Hello World");
> 			message.setStatus(Message.HELLO);
> 			System.out.println("Inserting message");
> 			ksession.insert(message);
> 			System.out.println("Fire all rules");
> 			ksession.fireAllRules();
> 			System.out.println("Sleep 10");
> 			Thread.sleep(10000);
> 			System.out.println("End sleep");
> 			logger.close();
> 		} catch (Throwable t) {
> 			t.printStackTrace();
> 		}
> 	}
>
> 	private static KnowledgeBase readKnowledgeBase() throws Exception {
> 		KnowledgeBaseConfiguration conf = KnowledgeBaseFactory
> 				.newKnowledgeBaseConfiguration();
> 		conf.setOption(EventProcessingOption.STREAM); // STREAM mode as we are
> 														// dealing with Events	
>
> 		KnowledgeBuilder kbuilder = KnowledgeBuilderFactory
> 				.newKnowledgeBuilder();
> 		kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"),
> 				ResourceType.DRL);
> 		KnowledgeBuilderErrors errors = kbuilder.getErrors();
> 		if (errors.size() > 0) {
> 			for (KnowledgeBuilderError error : errors) {
> 				System.err.println(error);
> 			}
> 			throw new IllegalArgumentException("Could not parse knowledge.");
> 		}
> 		KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(conf);
> 		kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
> 		return kbase;
> 	}
>
> 	public static class Message {
>
> 		public static final int HELLO = 0;
> 		public static final int GOODBYE = 1;
>
> 		private String message;
>
> 		private int status;
>
> 		public String getMessage() {
> 			return this.message;
> 		}
>
> 		public void setMessage(String message) {
> 			this.message = message;
> 		}
>
> 		public int getStatus() {
> 			return this.status;
> 		}
>
> 		public void setStatus(int status) {
> 			this.status = status;
> 		}
>
> 	}
>
> }
>
>
>
> --
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