How does the condition functionality work in Logback?

Question

I use this logback configuration file:

<configuration>
  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%-10.-10thread] %-5level %-30logger{1} - %msg%n</pattern>
    </encoder>
  </appender>

<if condition='isDefined("fileout-dir")'><then>
  <appender name="SIFT" class="ch.qos.logback.classic.sift.SiftingAppender">
     <discriminator  class="edu.kit.sdq.storagebenchmarkharness.logging.SBHThreadDiscriminator"/>
    <sift>
      <appender name="FILE-${thread}" class="ch.qos.logback.core.FileAppender">
        <file>${fileout-dir:-}${thread}.log</file>
        <append>true</append>
        <layout class="ch.qos.logback.classic.PatternLayout">
          <pattern>%d{HH:mm:ss.SSS} %-5level %-30logger{1} - %msg%n</pattern>
        </layout>
      </appender>
    </sift>
  </appender>
  <root>
    <appender-ref>SIFT</appender-ref>
  </root>
 </then> </if>

  <root level="debug">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

When running my application, I get the following error:

org.codehaus.commons.compiler.CompileException: Line 1, Column 45: A method named "isDefined" is not declared in any enclosing class nor any supertype, nor through a static import
    at org.codehaus.commons.compiler.CompileException: Line 1, Column 45: A method named "isDefined" is not declared in any enclosing class nor any supertype, nor through a static import
    at  at org.codehaus.janino.UnitCompiler.compileError(UnitCompiler.java:9014)
    at  at org.codehaus.janino.UnitCompiler.findIMethod(UnitCompiler.java:6549)
    at  at org.codehaus.janino.UnitCompiler.compileGet2(UnitCompiler.java:3429)
    at  at org.codehaus.janino.UnitCompiler.access$6300(UnitCompiler.java:104)
    at  at org.codehaus.janino.UnitCompiler$11.visitMethodInvocation(UnitCompiler.java:2869)
    at  at org.codehaus.janino.Java$MethodInvocation.accept(Java.java:2831)
    at  at org.codehaus.janino.UnitCompiler.compileGet(UnitCompiler.java:2890)
    at  at org.codehaus.janino.UnitCompiler.compileGetValue(UnitCompiler.java:3897)
    at  at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:1637)
    at  at org.codehaus.janino.UnitCompiler.access$1700(UnitCompiler.java:104)
    at  at org.codehaus.janino.UnitCompiler$5.visitReturnStatement(UnitCompiler.java:877)
    at  at org.codehaus.janino.Java$ReturnStatement.accept(Java.java:1803)
    at  at org.codehaus.janino.UnitCompiler.compile(UnitCompiler.java:888)
    at  at org.codehaus.janino.UnitCompiler.compileStatements(UnitCompiler.java:914)
    at  at org.codehaus.janino.UnitCompiler.compile(UnitCompiler.java:1999)
    at  at org.codehaus.janino.UnitCompiler.compileDeclaredMethods(UnitCompiler.java:789)
    at  at org.codehaus.janino.UnitCompiler.compileDeclaredMethods(UnitCompiler.java:770)
    at  at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:464)
    at  at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:357)
    at  at org.codehaus.janino.UnitCompiler$3.visitPackageMemberClassDeclaration(UnitCompiler.java:312)
    at  at org.codehaus.janino.Java$PackageMemberClassDeclaration.accept(Java.java:770)
    at  at org.codehaus.janino.UnitCompiler.compile(UnitCompiler.java:319)
    at  at org.codehaus.janino.UnitCompiler.compileUnit(UnitCompiler.java:288)
    at  at org.codehaus.janino.SimpleCompiler.compileToClassLoader(SimpleCompiler.java:393)
    at  at org.codehaus.janino.ClassBodyEvaluator.compileToClass(ClassBodyEvaluator.java:311)
    at  at org.codehaus.janino.ClassBodyEvaluator.cook(ClassBodyEvaluator.java:224)
    at  at org.codehaus.janino.SimpleCompiler.cook(SimpleCompiler.java:194)
    at  at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:80)
    at  at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:72)
    at  at ch.qos.logback.core.joran.conditional.PropertyEvalScriptBuilder.build(PropertyEvalScriptBuilder.java:34)
    at  at ch.qos.logback.core.joran.conditional.IfAction.begin(IfAction.java:43)
    at  at ch.qos.logback.core.joran.spi.Interpreter.callBeginAction(Interpreter.java:273)
    at  at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:145)
    at  at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:127)
    at  at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:40)
    at  at ch.qos.logback.core.joran.spi.Interpreter.play(Interpreter.java:332)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:126)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:93)
    at  at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:52)
    at  at ch.qos.logback.classic.util.ContextInitializer.configureByResource(ContextInitializer.java:60)
    at  at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:121)
    at  at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:85)
    at  at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55)
    at  at org.slf4j.LoggerFactory.bind(LoggerFactory.java:121)
    at  at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:111)
    at  at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:268)
    at  at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:241)
    at  at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:254)
    at  at edu.kit.sdq.storagebenchmarkharness.Logger.getLogger(Logger.java:44)
    at  at edu.kit.sdq.storagebenchmarkharness.BenchmarkController.<clinit>(BenchmarkController.java:66)

Why is the method isDefined unkown? The logback docs state that it should exists, and at least one stack overflow thread seems to use it.

I included the most recent version of janino in my classpath because it is needed for the evalution of the expressions. The janino compiler gets loaded as you can see in the error message.

Which version of logback are you using? – Ceki Jun 13 '12 at 16:35 — Ceki, Jun 13 '12 at 16:35

JBCP · Answer 1 · 2013-04-09T19:42:50.540

9

Make sure you are using the latest version of logback. In addition, using conditionals in logback requires the Janino library.

Add this to your pom.xml file to get the dependency:

    <!-- The org.codehaus.janino:commons-compiler:2.6.1 dependency -->
    <!-- will be automatically pulled in by Maven's transitivity rules -->
    <dependency>
        <groupId>org.codehaus.janino</groupId>
        <artifactId>janino</artifactId>
        <version>2.6.1</version>
    </dependency>

edited Apr 09 '13 at 19:42

answered Apr 09 '13 at 19:15

JBCP

13,109
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1

logback's "default value for variables" functionality may be helpful here. See http://logback.qos.ch/manual/configuration.html#defaultValuesForVariables – Ceki Apr 09 '13 at 21:00
Just adding the janino artifact is not enough. The janino page tells you you need to add commons compiler also. – djangofan Nov 22 '17 at 22:18
The [Janino manual](https://janino-compiler.github.io/janino/#packages) shows that only `org.codehaus.janino.janino` needs to be imported. That's because `commons-compiler` is a dependency in Janinio's pom file and will automatically be imported. I realize this may not have been true when the question was asked/answered but now only 1 import is required. – Paul Feb 12 '22 at 21:02

How does the condition functionality work in Logback?

1 Answers1

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