Logging exceptions when firing rules with ConsequenceExceptionHandler

I have my drools server configured via spring/camel and I'd like to be able log to a file all runtime exceptions that occur when rules are fired, along with details about the state of the working memory at the time of the exception.

I found that drools version >= 5.2 of drools-spring does allow for the setting of a custom ConsequenceExceptionHandler class in the spring configuration:

https://issues.jboss.org/browse/JBRULES-2674

I'm having some trouble (some of which related from migrating from drools 5.1 to 5.2) so I was wondering if anyone has done the logging of exceptions before and could share some implementation details. Or if someone can tell me if there's a better way to achieve this than through a c开发者_如何学编程ustom exception handler.

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In my project (I think I'll have to write about it on my blog http://toomuchcoding.blogspot.com where I have some articles about Drools) I wrote a custom Listener in the following manner (I think I found a nice tutorial over here http://members.inode.at/w.laun/drools/CustomConsequenceExceptionHandlingHowTo.html)

I defined my KnowledgeBase as a bean in my applicationContext:

<drools:kbase id="fxKBase">
    <drools:resources>
        <drools:resource type="DRL" source="classpath:path/first.drl"/>
        <drools:resource type="DRL" source="classpath:path/second.drl"/>
    </drools:resources>
    <drools:configuration>
        <drools:consequenceExceptionHandler handler="a.b.c.MyConsequenceExceptionHandler" />
    </drools:configuration>
</drools:kbase>

Then I defined MyConsequenceExceptionHandler

public class MyConsequenceExceptionHandler implements ConsequenceExceptionHandler {
@Override
public void handleException(Activation activation, WorkingMemory workingMemory, Exception exception) {
    throw new MyConsequenceException(activation, workingMemory, exception);
}

and the MyConsequenceException:

public class MyConsequenceException extends RuntimeException {
private final WorkingMemory workingMemory;
private final Activation activation;

public MyConsequenceException(final Activation activation, final WorkingMemory workingMemory, final Exception exception) {
    super(exception);
    this.activation = activation;
    this.workingMemory = workingMemory;
}

@Override
public String getMessage() {
    StringBuilder sb = new StringBuilder( "Exception executing consequence for " );
    if( activation != null && ( activation.getRule() ) != null ){
        Rule rule = activation.getRule();
        String ruleName = rule.getName();
        sb.append("rule [\"").append( ruleName ).append( "\"]. " );
    } else {
        sb.append( "rule, name unknown" );
    }
    Throwable throwable = ExceptionUtils.getRootCause(getCause());
    sb.append("The thrown exception is [").append(throwable).append("]. ");
    return sb.toString();
}

@Override
public String toString() {
    return getMessage();
} 

}

In that way when an exception is thrown you will get a custom message of your choosing.