SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". in a Maven Project

Question

I have a dependency for SLF4J. I am getting this error:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

Here is my maven entry:

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.6.6</version>
    </dependency>

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.6.6</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.16</version>
    </dependency>

Where is the problem?

EDIT: Without log4j dependency I get the following exception

Failed to instantiate SLF4J LoggerFactory
Reported exception:
java.lang.NoClassDefFoundError: org.slf4j.impl.StaticLoggerBinder
    at org.slf4j.LoggerFactory.bind(LoggerFactory.java:121)
    at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:111)
    at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:268)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:241)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:254)
    at org.apache.bval.jsr303.ConfigurationImpl.<clinit>(ConfigurationImpl.java:50)
    at java.lang.J9VMInternals.initializeImpl(Native Method)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:228)
    at org.apache.bval.jsr303.ApacheValidationProvider.createGenericConfiguration(ApacheValidationProvider.java:66)
    at javax.validation.Validation$GenericBootstrapImpl.configure(Validation.java:173)
    at javax.validation.Validation.buildDefaultValidatorFactory(Validation.java:50)
    at com.daimler.zv9.basic.entity.AbstractEntity.<clinit>(AbstractEntity.java:73)
    at java.lang.J9VMInternals.initializeImpl(Native Method)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:228)
    at java.lang.J9VMInternals.initialize(J9VMInternals.java:195)
    at java.lang.Class.forNameImpl(Native Method)
    at java.lang.Class.forName(Class.java:168)

EDIT2: It is an example MAVEN Tree that I get

[INFO] com.myCompany.abc:ABC_Document:ejb:0.0.1-SNAPSHOT
[INFO] +- com.myCompany.abc:ABC_Basic:jar:0.0.1-SNAPSHOT:compile
[INFO] +- com.myCompany.iap:javax.j2ee:jar:5.0.0:provided
[INFO] +- com.myCompany.iap:logging:jar:5.0.0:provided
[INFO] +- com.myCompany.iap:util:jar:5.0.0:provided
[INFO] +- junit:junit:jar:4.8.2:test
[INFO] +- javax.servlet:jstl:jar:1.2:provided
[INFO] +- org.slf4j:slf4j-api:jar:1.6.6:compile
[INFO] +- org.slf4j:slf4j-simple:jar:1.6.6:compile
[INFO] \- org.mockito:mockito-all:jar:1.9.0:test

@basiljames i get the error with mvn openjpa:sql command. it is not installed anywhere. — Kayser, Sep 17 '12 at 11:49
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/16775/discussion-between-basiljames-and-kayser) — basiljames, Sep 17 '12 at 12:25
It looks like the version of slf4j-api that actually runs cannot find slf4j-log4j12 on its classpath. Are you sure that there isn't another slf4j-api.jar in your classpath? — Nicola Musatti, Sep 17 '12 at 12:41
@NicolaMusatti there are also Websphere 8 libraries but there is no slf4j-api.jar between them — Kayser, Sep 17 '12 at 12:46
With WAS 7 I remember solving similar problems by setting an option that reversed classpath traversal, putting application specific libraries first. — Nicola Musatti, Sep 17 '12 at 13:21
@Kayser My answer did not provide a solution to your problem.? — Konstantinos Margaritis, Oct 08 '13 at 17:34

score 43 · Accepted Answer · edited May 23 '17 at 11:47

I am assuming you are using Eclipse as your developing environment.

Eclipse Juno, Indigo and Kepler when using the bundled maven version(m2e), are not suppressing the message SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". This behaviour is present from the m2e version 1.1.0.20120530-0009 and onwards.

Although, this is indicated as an error your logs will be saved normally. The highlighted error will still be present until there is a fix of this bug. More about this in the m2e support site.

The current available solution is to use an external maven version rather than the bundled version of Eclipse. You can find about this solution and more details regarding this bug in the question below which i believe describes the same problem you are facing.

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". error

If the use of external maven version does not work, I advise to delete the content of your local Maven repository. — Kowlown, Feb 24 '15 at 13:22
I had the same problem on Intellij IDEA and the same solution ("use an external maven version rather than the bundled version") works for me. — Dherik, Aug 20 '18 at 15:31

basiljames · Answer 2 · 2012-09-17T12:35:56.260

39

Remove

<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.16</version>
</dependency>

slf4j-log4j12 is the log4j binding for slf4j you dont need to add another log4j dependency.

Added
Provide the log4j configuration in log4j.properties and add it to your class path. There are sample configurations here

or you can change your binding to

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <version>1.6.1</version>
</dependency>

if you are configuring slf4j due to some dependencies requiring it.

edited Sep 17 '12 at 12:35

answered Sep 17 '12 at 11:45

basiljames

4,777
4
24
41

I removed it. I am getting this exception 'Failed to instantiate SLF4J LoggerFactory Reported exception: java.lang.NoClassDefFoundError: org.slf4j.impl.StaticLoggerBinder at org.slf4j.LoggerFactory.bind(LoggerFactory.java:121) at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:111) at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:268)' – Kayser Sep 17 '12 at 11:47
One similar [post](http://stackoverflow.com/questions/7421612/slf4j-failed-to-load-class-org-slf4j-impl-staticloggerbinder) – basiljames Sep 17 '12 at 11:54
When slf4j-log4j is declared a dependency adding log4j as a dependency is unnecessary but it should not hurt either. Moreover, log4j.properties is irrelevant to the question being asked. – Ceki Sep 17 '12 at 20:46
thanks worked for me – Tayab Hussain Jan 20 '17 at 18:29
thanks! It helped me. – Huanfa Chen May 16 '17 at 16:00

score 17 · Answer 3 · answered Feb 21 '13 at 22:48

I ran into this in IntelliJ and fixed it by adding the following to my pom:

<!-- logging dependencies -->
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>${logback.version}</version>
        <exclusions>
            <exclusion>
                <!-- Defined below -->
                <artifactId>slf4j-api</artifactId>
                <groupId>org.slf4j</groupId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>${slf4j.version}</version>
    </dependency>

A better fix would be to use a `dependencyManagement` element which nails down the version for `slf4j-api` — Aaron Digulla, May 21 '15 at 15:19

Ceki · Answer 4 · 2012-09-19T08:59:56.603

2

The message you mention is quite clear:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

SLF4J API could not find a binding, and decided to default to a NOP implementation. In your case slf4j-log4j12.jar was somehow not visible when the LoggerFactory class was loaded into memory, which is admittedly very strange. What does "mvn dependency:tree" tell you?

The various dependency declarations may not even be directly at cause here. I strongly suspect that a pre-1.6 version of slf4j-api.jar is being deployed without your knowledge.

edited Sep 19 '12 at 08:59

answered Sep 17 '12 at 17:45

Ceki

26,753
7
62
71

That is what dependency:tree tells: `[INFO] [INFO] --- maven-dependency-plugin:2.5.1:tree (default-cli) @ GEM_Web --- [INFO] com.mycompany.proj:My_Web:war:0.0.1-SNAPSHOT ... [INFO] +- javax.servlet:jstl:jar:1.2:provided [INFO] +- org.slf4j:slf4j-api:jar:1.6.6:compile [INFO] +- org.slf4j:slf4j-simple:jar:1.6.6:compile [INFO] \- org.mockito:mockito-all:jar:1.9.0:test` – Kayser Sep 18 '12 at 11:38
The above is not very legible. IMO, it should be moved to the question part. – Ceki Sep 19 '12 at 09:00

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". in a Maven Project

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