Replacing JaninoEventEvaluator

[stephan-roolvink]

In 1.5.13 the JaninoEventEvaluator was removed, I'm seeing that documentation regarding creating filters has not been updated, but I really would like to change my filters so they work with 1.5.13 and beyond. Is there somebody who can help me out?

Out filter looks like this now

        <filter class="ch.qos.logback.core.filter.EvaluatorFilter">
            <evaluator>
                <matcher>
                    <Name>requestRejectedException</Name>
                    <regex>RequestRejectedException.*</regex>
                </matcher>
                <expression>requestRejectedException.matches(formattedMessage)</expression>
            </evaluator>
            <OnMismatch>NEUTRAL</OnMismatch>
            <OnMatch>DENY</OnMatch>
        </filter>

[ceki]

Update: An online tool called Janino expression migrator was deployed earlier today, January 5th 2025. It should help users migrate their configuration files using JaninoEventEvaluator.

In general, it should be fairly easy to migrate the functionality of a JaninoEventEvaluator setup to a custom EventEvaluator.

I suggest to subclass EventEvaluatorBase and implement the evaluate(ILoggingEvent) method to return a boolean.

For example, here is an evaluator class approximating your example above.

import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.spi.IThrowableProxy;
import ch.qos.logback.core.boolex.EvaluationException;
import ch.qos.logback.core.boolex.EventEvaluatorBase;

public class ExceptionMatchEvaluator extends EventEvaluatorBase<ILoggingEvent> {

    String exceptionClass;
    private boolean start = false;

    public void start() {
        if (exceptionClass == null) {
            addError("The exceptionClass must be set");
            return;
        }
        start = true;
    }

    public void stop() {
        start = false;
    }

    public boolean isStarted() {
        return start;
    }

    @Override
    public boolean evaluate(ILoggingEvent event) throws NullPointerException, EvaluationException {

        IThrowableProxy throwableProxy = event.getThrowableProxy();
        if (throwableProxy == null) {
            return false;
        }
        return throwableProxy.getClassName().equalsIgnoreCase(exceptionClass);
    }

    public String getExceptionClass() {
        return exceptionClass;
    }

    public void setExceptionClass(String exceptionClass) {
        this.exceptionClass = exceptionClass;
    }
}

And here is a sample logback.xml configuration file screening for java. lang. RuntimeException.

   <configuration>
      <import class="ch. qos.logback.classic.encoder.PatternLayoutEncoder">
      <import class="ch. qos.logback.core.filter.EvaluatorFilter">
      <import class="ch. qos.logback.classic.boolex.ExceptionMatchEvaluator">
      <import class="ch. qos.logback.core.ConsoleAppender">
 
      <appender name="CONSOLE" class="ConsoleAppender">
          <filter class="EvaluatorFilter">
              <evaluator class="ExceptionMatchEvaluator">
                  <exceptionClass>java. lang. RuntimeException</exceptionClass>
              </ evaluator>
              <OnMismatch>DENY</OnMismatch>
              <OnMatch>NEUTRAL</OnMatch>
          </ filter>
 
          <encoder class="PatternLayoutEncoder">
              <pattern>%-4relative [%thread] %-5level %logger -%kvp -%msg%n</pattern>
          </ encoder>
      </ appender>
 
      <root level="INFO">
          <appender-ref ref="CONSOLE">
      </ root>
  </ configuration>

[ceki]

Added ExceptionMatchEvaluator in commit 020610a

Documentation will be updated shortly

[Cesaario]

I had some problems with JaninoEventEvaluator after updating logback to version 1.5.15 but I couldn't solve it with the solution from above. I was able to solve this issue by updating logback-access to version 2.0.5. Just be aware that you will need to rename the package from ch.qos.logback.access:common to ch.qos.logback.access:logback-access-common (the same if you use ch.qos.logback.access:tomcat).

[ceki]

@Cesaario Your comment seems unrelated to the issue at hand, namely the removal of JaninoEventEvaluator. May I suggest to create a new discussion?

[Cesaario]

Sorry about that. It's just because I stumbled upon this discussion when searching for a solution for my problem, so maybe it could be useful for someone with the same problem. I don't think a new discussion is needed.

[ceki]

@stephan-roolvink An online tool called Janino expression migrator was deployed earlier today, January 5th 2025. It should help users migrate their configuration files using JaninoEventEvaluator.

[stephan-roolvink]

Thanks for the answer I was aware of creating an evaluator for this, I was hoping for a way to avoid it as it add more code to maintain.