CODEWITHSUNDEEP
javalogginglog4jslf4jlogback
Chris Watts
Chris Watts

Reputation: 2344

Using Logback but Log4j started displaying WARN no Appenders

I am using logback for my logging and it has been working however; the other day I started getting a warning

log4j:WARN No appenders could be found for logger (org.apache.axis.i18n.ProjectResourceBundle). log4j:WARN Please initialize the log4j system properly.

I am not using log4j nor have I ever with this project. I have a logback.xml in my resources folder.

Any ideas on why this warning started to show up?

Upvotes: 18

Views: 19645

Answers (2)

theadam
theadam

Reputation: 4051

You must be using a library that does use log4j. Can you post anything more about your project?

You should probably just put log4j bridge on the classpath. Read more here: http://www.slf4j.org/legacy.html

The jar you want to look into is log4j-over-slf4j. It will bridge log4j API to actually make calls to your implementation of slf4j API (in your case - logback).

If you are using Maven to build your project then it might be as simple as putting

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>log4j-over-slf4j</artifactId>
    <version>1.7.7</version>
</dependency>

in dependencies.

Excluding a library (if needed) would be done in this fashion (this assumes we are talking about the transitive dependency from the jar you've mentioned):

    <dependency>
        <groupId>org.swift.common</groupId>
        <artifactId>jira-soap</artifactId>
        <version>4.4.0</version>
        <exclusions>
            <exclusion>
                <groupId>...</groupId>
                <artifactId>...</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

Upvotes: 20

Avec
Avec

Reputation: 1761

Took me some time to find out since the message was log4j:WARN No appenders could be found for logger

I tried to exclude log4j and I tried the log4j-over-slf4j.

Then I ran mvn dependency:tree and finally found out that mye commons-configuration actually was using commons-logging

[INFO] +- commons-configuration:commons-configuration:jar:1.9:compile
[INFO] |  \- commons-logging:commons-logging:jar:1.1.1:compile
[INFO] +- ch.qos.logback:logback-classic:jar:1.0.13:compile
[INFO] |  +- ch.qos.logback:logback-core:jar:1.0.13:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.5:compile
[INFO] +- org.slf4j:log4j-over-slf4j:jar:1.7.6:compile
[INFO] \- org.apache.commons:commons-lang3:jar:3.1:compile

This became the solution for me.

    <!-- logging with logback (and slf4j)-->
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.0.13</version>
    </dependency>

    <!-- had a dep in commons-configuration -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>jcl-over-slf4j</artifactId>
        <version>1.7.6</version>
    </dependency>

Upvotes: 9

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