Hello.

I am trying to implement logback/slf4j and an extremely frustrating thing is occurring when I run my unit tests. All of the log messages are being duplicated. I am aware of the whole additive nature of appenders and I am pretty sure that I am doing things correctly in that regard but the messages continue to duplicate when running unit tests. When I run through a main method, they do not. Here is my configuration and the messages that are displayed when running unit tests.

Dependencies I have included (via Ivy):

<dependency org="org.slf4j" name="slf4j-api" rev="1.6.4"/>
<dependency org="ch.qos.logback" name="logback-core" rev="1.0.0"/>
<dependency org="ch.qos.logback" name="logback-classic" rev="1.0.0"/>

Configuration:

<configuration debug="true">
    <contextName>example-test</contextName>
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} %-5level %logger - %msg%n</pattern>
        </encoder>
    </appender>
    <logger name="com.example" level="debug"/>
    <root level="warn">
        <appender-ref ref="STDOUT"/>
    </root>
</configuration>

Log output when running unit tests:

13:44:23,308 |-INFO in ch.qos.logback.classic.joran.action.ContextNameAction - Setting logger context name as [example-test]
13:44:23,308 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
13:44:23,313 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
13:44:23,344 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
13:44:23,431 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.example] to DEBUG
13:44:23,431 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to WARN
13:44:23,431 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT]
13:44:23,433 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.

13:44:23.453 INFO com.example.project.service.impl.ExampleClassImpl - This is a test.
13:44:23.466 INFO com.example.project.service.impl.ExampleClassImpl - This is a test.

Log output when running under main method:

13:48:16,729 |-INFO in ch.qos.logback.classic.joran.action.ContextNameAction - Setting logger context name as [example-test]
13:48:16,729 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
13:48:16,734 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
13:48:16,760 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
13:48:16,825 |-INFO in ch.qos.logback.classic.joran.action.LoggerAction - Setting level of logger [com.example] to DEBUG
13:48:16,825 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to WARN
13:48:16,825 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT]
13:48:16,827 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.

13:48:16.843 INFO com.example.project.service.impl.ExampleClassImpl - This is a test.

I know that the unit tests are picking up my configuration correctly. When I examine my unit test results, I can see that tests are only being run once so I it is not a duplicate execution of the code. Is there anything special I have to do to stop the duplicates when running unit tests? Thanks for your help.

--Matt--