SLF4J: Failed to load class “org.slf4j.impl.Static

问题:

• Regarding Eclipse IDE (Indigo, Juno and Kepler (32 and 64 bit versions))
• Platforms: Windows, Ubuntu, Mac
• m2e version: 1.1.0.20120530-0009, 1.2.0.20120903-1050, 1.3.0.20130129-0926,
  1.4.0.20130601-0317

---

General info

The above error came after updating the m2e to version 1.1. By removing m2e 1.1 and rolling back to m2e 1.0 everything worked fine. I tried to repeat the problem in Windows and Ubuntu and it gave me the exact same error. Numerous configurations of the slf4j-api and logback were tested but none seem to work.

The error appears in any maven project even without declaring slf4j dependency.

• New Maven Project--> maven-archetype-quickstart

  and

• New Maven Project--> Simple project without archetype selection

  result to

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

---

Testing enviroments and configurations

Tested with Eclipse Indigo and Eclipse Juno (32 and 64 bit both) on Mac, 32 bit on Ubuntu and 64 and 32 bit on Windows. Tested fresh installs of Juno Classic, Juno Modelling tools, Kepler Standard, Kepler Modelling Tools and produced the same error.

The error appears with clean, install, test, deploy, generate-sources, validate , compile , package, integration-test, verify and combinations of the goal clean with the rest goals. It appears also with parameters -e and -X. There was an attempt to delete the m2e repository and download it from scratch but again without success. It should me mentioned that it was tested in 3 different machines and virtual box all the above systems but it produced the same error.

Tried all different logback configurations (from 1.0.4 to 1.0.13) that resolve the slf4j-api and logback-core dependencies, but all produce the same error:

<dependency>
   <groupId>ch.qos.logback</groupId>
   <artifactId>logback-classic</artifactId>
   <version></version>
</dependency>

Tried all different (from 1.6.1 to 1.7.5 ) slf4j-simple configurations.

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

Tried all different (from 1.6.1 to 1.7.5 ) log4j-over-slf4j configurations.

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

Tried all different (from 1.6.1 to 1.7.5 ) slf4j-jdk14 configurations.

<dependency>
   <groupId>org.slf4j</groupId>
   <artifactId>slf4j-jdk14</artifactId>
   <version></version>
   <scope>compile</scope>
</dependency>

Tried all different (from 1.6.1 to 1.7.5 ) slf4j-log4j12 configurations.

<dependency>
     <groupId>org.slf4j</groupId>
     <artifactId>slf4j-log4j12</artifactId>
     <version></version>
     <scope>compile</scope>
</dependency>

Tried slf4j-nop 1.7.5 configuration.

<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-nop</artifactId>
  <version>1.7.5</version>
  <scope>compile</scope>
</dependency>

Last but not least the logs are saved and printed despite the error.

---

Ways to reproduce the error

• Download Eclipse Juno, Indigo or Kepler 32 or 64 bit (All installations will cause the same error).

  • Install m2e - Maven Integration for Eclipse

    • Juno - http://download.eclipse.org/releases/juno
    • Kepler - http://download.eclipse.org/releases/kepler
    • Indigo - http://download.eclipse.org/technology/m2e/releases/ (currently unavailable)

    OR

  • Update your m2e version to 1.1.0.20120530-0009, or 1.2.0.20120903-1050, or 1.3.0.20130129-0926, or 1.4.0.20130601-0317 )

    ---

  • Select File->New->Other->Maven Project->Click Next->Select
    maven-archetype-quickstart from the catalog->Finish

    OR

  • Select File->New->Other->Maven Project->Click Next->Select Create a simple project (skip archetype selection)-> Complete Artifact info-> Finish

• Right Click on the project->Runs As->clean install (or any other goal mentioned above)

The first line on the console will be

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.

P.S. Existing projects will produce the same error after updating the m2e version to 1.1.0.20120530-0009, 1.2.0.20120903-1050, 1.3.0.20130129-0926, 1.4.0.20130601-0317

---

Updates

EDIT

m2e support site:

• The above question was posted as a bug in m2e support site and the answer from Igor Fedorenko was that

  There are no immediate plans to suppress this message.

  For viewing the above bug please refer to m2e official support site

---

EDIT 2

• The above error indication is present also to m2e version 1.2.0.20120903-1050

---

EDIT 3

• The above error indication is present also to m2e version 1.3.0.20130129-0926

---

EDIT 4

• The above error indication is present also to m2e version 1.4.0.20130601-0317

---

EDIT 5

                              ***Reported FIXED***

• The above error is reported as fixed for m2e version 1.5.0/Luna M3(Target Milestone). The version is not yet available for download.
• Luna M3 is scheduled for Nov. 15th.
• Latest dev build are available here
• More information about the m2e milestones you can find at the m2e main repository.

回答1:

I can also confirm this error.

Workaround: is to use external maven inside m2eclipse, instead of it\'s embedded maven.

That is done in three steps:

1 Install maven on local machine (the test-machine was Ubuntu 10.10)

mvn --version

Apache Maven 2.2.1 (rdebian-4) Java version: 1.6.0_20 Java home: /usr/lib/jvm/java-6-openjdk/jre Default locale: de_DE, platform encoding: UTF-8 OS name: \"linux\" version: \"2.6.35-32-generic\" arch: \"amd64\" Family: \"unix\"

2 Run maven externally link how to run maven from console

> cd path-to-pom.xml
> mvn test

    [INFO] Scanning for projects...
    [INFO] ------------------------------------------------------------------------
    [INFO] Building Simple
    [INFO]    task-segment: [test]
    [INFO] ------------------------------------------------------------------------
    [...]
    [INFO] Surefire report directory: [...]/workspace/Simple/target/surefire-reports

    -------------------------------------------------------
     T E S T S
    -------------------------------------------------------
    Running net.tverrbjelke.experiment.MainAppTest
    Hello World
    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.042 sec

    Results :

    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESSFUL
    [INFO] ------------------------------------------------------------------------
    [...]

3 inside m2eclipse: switch from embedded maven to local maven

• find out where local maven home installation dir is (mvn --version, or google for your MAVEN_HOME, for me this helped me that is /usr/share/maven2 )
• in eclipse Menu->Window->Preferences->Maven->Installation-> enter that string. Then you should have switched to your new external maven.
• then run your Project as e.g. \"maven test\".

The error-message should be gone.

回答2:

There is a documentation in SLf4J site to resolve this. I followed that and added slf4j-simple-1.6.1.jar to my aplication along with slf4j-api-1.6.1.jar which i already had.This solved my problem

slf4j

回答3:

If you are using Gradle add this:

dependencies { 
... 
compile \"org.slf4j:slf4j-simple:1.7.9\" 
... 
}

回答4:

Had similar error with the same result with Gradle and was able to solve it by following:

//compile \'org.slf4j:slf4j-api:1.7.1\'
compile group: \'org.apache.logging.log4j\', name: \'log4j-api\', version: \'2.1\'
compile group: \'org.apache.logging.log4j\', name: \'log4j-core\', version: \'2.1\'
compile group: \'org.apache.logging.log4j\', name: \'log4j-slf4j-impl\', version: \'2.1\'

Out-commented line is the one which caused the error output. I believe you can transfer this to Maven.

回答5:

You haven\'t specify version in your maven dependency file may be thats why it is not picking the latest jar
As well as you need another deppendency with slf4j-log4j12 artifact id.
Include this in your pom file

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.5.6</version>
</dependency>

Let me know if error is still not resolved
I also recomend you to see this link

回答6:

Paste this code to your pom.xml file. It works for me.

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

回答7:

Had been over looking the issue having surfaced it. Believe this will be a good read for others who come down here with the same issue:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=387064

回答8:

I had the similar issue for my Spring Boot - Gradle application running on Eclipse Luna. I could resolve it by manually adding an entry in my project\'s .classpath

<classpathentry sourcepath=\"C:/Users/<username>/.gradle/caches/modules-2/files-2.1/org.slf4j/slf4j-simple/1.7.7/3150039466ad03e6ef1c7ec1c2cbb0d96710cf64/slf4j-simple-1.7.7-sources.jar\" kind=\"lib\" path=\"C:/Users/<username>/.gradle/caches/modules-2/files-2.1/org.slf4j/slf4j-simple/1.7.7/8095d0b9f7e0a9cd79a663c740e0f8fb31d0e2c8/slf4j-simple-1.7.7.jar\"/>

Idea is to follow this solution. But how to implement is dependent on case to case. One way of fixing is the one that I used above.

Hope this helps.

回答9:

This is not an error message but a warning. It is very clearly explained in their website as :

This warning, i.e. not an error, message is reported when no SLF4J providers could be found on the class path. Placing one (and only one) of slf4j-nop.jar slf4j-simple.jar, slf4j-log4j12.jar, slf4j-jdk14.jar or logback-classic.jar on the class path should solve the problem. Note that these providers must target slf4j-api 1.8 or later.

In the absence of a provider, SLF4J will default to a no-operation (NOP) logger provider.

https://www.slf4j.org/codes.html#StaticLoggerBinder