My application is to be deployed on both tcServer and WebSphere 6.1. This application uses ehCache and so requires slf4j as a dependency. As a result I've added the slf4j-api.jar (1.6) jar to my war file bundle.
The application works fine in tcServer except for the following 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.
However, when I deploy in WebSphere I get a java.lang.NoClassDefFoundError: org.slf4j.impl.StaticLoggerBinder.
Also accompanied by Failed to load class "org.slf4j.impl.StaticMDCBinder"
I've checked the classpaths of both application servers and there is no other slf4j jar.
Does anyone have any ideas what may be happening here?
Sometime we should see the note from the warnin SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details..
This happens when no appropriate SLF4J binding could be found on the class path
You can search the reason why this warning comes.
Adding one of the jar from *slf4j-nop.jar, slf4j-simple.jar, slf4j-log4j12.jar, slf4j-jdk14.jar or logback-classic.jar* to the class path should solve the problem.
compile "org.slf4j:slf4j-simple:1.6.1"
for example add the above code to your build.gradle or the corresponding code to pom.xml for maven project.
I got into this issue when I get the following 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.
when I was using slf4j-api-1.7.5.jar in my libs.
Inspite I tried with the whole suggested complement jars, like slf4j-log4j12-1.7.5.jar, slf4j-simple-1.7.5 the error message still persisted. The problem finally was solved when I added slf4j-jdk14-1.7.5.jar to the java libs.
Get the whole slf4j package at http://www.slf4j.org/download.html
For me the issue was: Using Hibernate, I saw that it already used slf4j, and it was in my classpath already, so I decided to use it. The next step - adding imlementor for slf4j, so I added to maven:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.7.25</version>
</dependency>
But it failed with error! SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”
The solution was: Hibernate's dependency of slf4j was version 1.7.26, and I added minor version dependency 1.7.25. So when I fixed this - all became OK
As SLF4J Manual states
The Simple Logging Facade for Java (SLF4J) serves as a simple facade or abstraction for various logging frameworks, such as java.util.logging, logback and log4j.
and
The warning will disappear as soon as you add a binding to your class path.
So you should choose which binding do you want to use.
NoOp binding (slf4j-nop)
Binding for NOP, silently discarding all logging.
Check fresh version at https://search.maven.org/search?q=g:org.slf4j%20AND%20a:slf4j-nop&core=gav
Simple binding (slf4j-simple)
outputs all events to System.err. Only messages of level INFO and higher are printed. This binding may be useful in the context of small applications.
Check fresh version at https://search.maven.org/search?q=g:org.slf4j%20AND%20a:slf4j-simple&core=gav
Bindings for the logging frameworks (java.util.logging, logback, log4j)
You need one of these bindings if you are going to write log to a file.
See description and instructions at https://www.slf4j.org/manual.html#projectDep
My opinion
I would recommend Logback because it's a successor to the log4j project.
Check latest version of the binding for it at https://search.maven.org/search?q=g:ch.qos.logback%20AND%20a:logback-classic&core=gav
You get console output out of the box but if you need to write logs into file just put FileAppender configuration to the src/main/resources/logback.xml or to the src/test/resources/logback-test.xml just like this:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<!-- encoders are assigned the type
ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<appender name="FILE" class="ch.qos.logback.core.FileAppender">
<file>logs/logs.log</file>
<encoder>
<pattern>%date %level [%thread] %logger{10} - %msg%n</pattern>
</encoder>
</appender>
<root level="debug">
<appender-ref ref="STDOUT" />
<appender-ref ref="FILE" />
</root>
<logger level="DEBUG" name="com.myapp"/>
</configuration>
(See detailed description in manual: https://logback.qos.ch/manual/configuration.html)
I did not add any dependencies, I just change the way I was consuming them.
(Uncomment this code if you are using elastic search version < 7.0)
IndexRequest indexRequest = new IndexRequest(
"twitter",
"tweets",
id // this is to make our consumer idempotent
).source(record.value(), XContentType.JSON);
IndexRequest indexRequest = new IndexRequest("tweets")
.source(record.value(), XContentType.JSON)
.id(id); // this is to make our consumer idempotent
I am using bulkrequest and with that I remove that error.
Quite a few answers here recommend adding the slf4j-simple dependency to your maven pom file. You might want to check for the most current version.
At https://mvnrepository.com/artifact/org.slf4j/slf4j-simple you'll find the latest version of the SLF4J Simple Binding. Pick the one that suites you best (still 1.7.30 from 2019-12 is the stable version as of 2020-10) and include it to your pom.xml.
For your convenience some dependencies are shown here - but they might not be up-to-date when you read this!
Alpha Version of 2019-10
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>2.0.0-alpha1</version>
</dependency>
Beta Version of Feb 2019
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.8.0-beta4</version>
</dependency>
Stable Version 2019-12
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.30</version>
</dependency>
I removed the scope test part thanks to the comment below.
I was facing same error. I have configured slf4j-api, slf4j-log4j12 and log4j, in my local development. All configuration was fine, but slf4j-log4j12 dependency which I copied from mvnrepository had test scope <scope>test</scope>. When I removed this every thing is fine.
Some times silly mistakes breaks our head ;)
As per the SLF4J Error Codes
Failed to load class org.slf4j.impl.StaticLoggerBinder This warning message is reported when the org.slf4j.impl.StaticLoggerBinder class could not be loaded into memory. This happens when no appropriate SLF4J binding 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 slf4j-api versions 2.0.x and later use the ServiceLoader mechanism. Backends such as logback 1.3 and later which target slf4j-api 2.x, do not ship with org.slf4j.impl.StaticLoggerBinder. If you place a logging backend which targets slf4j-api 2.0.x, you need slf4j-api-2.x.jar on the classpath. See also relevant faq entry.
SINCE 1.6.0 As of SLF4J version 1.6, in the absence of a binding, SLF4J will default to a no-operation (NOP) logger implementation.
If you are responsible for packaging an application and do not care about logging, then placing slf4j-nop.jar on the class path of your application will get rid of this warning message. Note that embedded components such as libraries or frameworks should not declare a dependency on any SLF4J binding but only depend on slf4j-api. When a library declares a compile-time dependency on a SLF4J binding, it imposes that binding on the end-user, thus negating SLF4J's purpose.
I added this dependency to resolve this issue:
https://mvnrepository.com/artifact/org.slf4j/slf4j-simple/1.7.25
Please add the following dependencies to pom to resolve this issue.
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.25</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.25</version>
</dependency>
I solve it adding this library: slf4j-simple-1.7.25.jar You can download this in official web https://www.slf4j.org/download.html
SLF4j is an abstraction for various logging frameworks. Hence apart from having slf4j you need to include any of your logging framework like log4j or logback (etc) in your classpath.
To have an idea refer the First Baby Step in http://logback.qos.ch/manual/introduction.html
Slf4j is a facade for the underlying logging frameworks like log4j, logback, java.util.logging.
To connect with underlying frameworks, slf4j uses a binding.
The above error is thrown if the binding jar is missed. You can download this jar and add it to classpath.
For maven dependency,
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.21</version>
</dependency>
This dependency in addition to slf4j-log4j12-1.7.21.jar,it will pull slf4j-api-1.7.21.jar as well as log4j-1.2.17.jar into your project
Reference: http://www.slf4j.org/manual.html
the solution is indicated on their official website :
Failed to load class org.slf4j.impl.StaticLoggerBinder
This warning message is reported when the org.slf4j.impl.StaticLoggerBinder class could not be loaded into memory. This happens when no appropriate SLF4J binding 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. SINCE 1.6.0 As of SLF4J version 1.6, in the absence of a binding, SLF4J will default to a no-operation (NOP) logger implementation. If you are responsible for packaging an application and do not care about logging, then placing slf4j-nop.jar on the class path of your application will get rid of this warning message. Note that embedded components such as libraries or frameworks should not declare a dependency on any SLF4J binding but only depend on slf4j-api. When a library declares a compile-time dependency on a SLF4J binding, it imposes that binding on the end-user, thus negating SLF4J's purpose.
solution : I have added to my project using maven research on intellij and i have chosen the slf4j-jdk14.jar.
encountered the same problem on payara 5.191
jcl-over-slf4j together with slf4j-log4j12 solved the problem
<properties>
<slf4j.version>1.7.29</slf4j.version>
</properties>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${slf4j.version}</version>
</dependency>
If you are using maven to dependency management so you can just add following dependency in pom.xml
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.5.6</version>
</dependency>
For non-Maven users Just download the library and put it into your project classpath.
Here you can see details: http://www.mkyong.com/wicket/java-lang-classnotfoundexception-org-slf4j-impl-staticloggerbinder/
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.21</version>
</dependency>
Put above mentioned dependency in pom.xml file
I use Jena and I add the fellowing dependence to pom.xml
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.0.13</version>
</dependency>
I try to add slf4j-simple but it just disappear the "SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”" error but logback-classic show more detail infomation.
I am working in a project Struts2+Spring. So it need a dependency slf4j-api-1.7.5.jar.
If I run the project, I am getting error like
Failed to load class "org.slf4j.impl.StaticLoggerBinder"
I solved my problem by adding the slf4j-log4j12-1.7.5.jar.
So add this jar in your project to solve the issue.
According to SLF4J official documentation
Failed to load class org.slf4j.impl.StaticLoggerBinder
This warning message is reported when the org.slf4j.impl.StaticLoggerBinder class could not be loaded into memory. This happens when no appropriate SLF4J binding 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.
Simply add this jar along with slf4j api.jar to your classpath to get things done. Best of luck
I was facing the similar problem with Spring-boot-2 applications with Java 9 library.
Adding the following dependency in my pom.xml solved the issue for me:
<dependency>
<groupId>com.googlecode.slf4j-maven-plugin-log</groupId>
<artifactId>slf4j-maven-plugin-log</artifactId>
<version>1.0.0</version>
</dependency>
Simply add this to your pom.xml:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.21</version>
</dependency>
As an alternative to the jar inclusion and pure maven solutions, you can include it from maven with gradle.
1.7.25// https://mvnrepository.com/artifact/org.slf4j/slf4j-simple
api group: 'org.slf4j', name: 'slf4j-simple', version: '1.7.25'
Put this within the dependencies of your build.gradle file.
Most likely your problem was because of <scope>test</scope> (in some cases also <scope>provided</scope>), as mentioned @thangaraj.
Documentation says:
This scope indicates that the dependency is not required for normal use of the application, and is only available for the test compilation and execution phases. Test dependencies aren’t transitive and are only present for test and execution classpaths.
So, if you don't need dependecies for test purposes then you can use instead of (what you will see in mvnrepository):
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-nop</artifactId>
<version>1.7.24</version>
<scope>test</scope>
</dependency>
Without any scopes (by default would be compile scope when no other scope is provided):
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-nop</artifactId>
<version>1.7.25</version>
</dependency>
This is the same as:
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-nop</artifactId>
<version>1.7.25</version>
<scope>compile</scope>
</dependency>
You need to add following jar file in your classpath: slf4j-simple-1.6.2.jar. If you don't have it, please download it. Please refer to http://www.slf4j.org/codes.html#multiple_bindings
This is for those who came here from google search.
If you use maven just add the following
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.5</version>
</dependency>
Or
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.6.4</version>
</dependency>
In the Websphere case, you have an older version of slf4j-api.jar, 1.4.x. or 1.5.x lying around somewhere. The behavior you observe on tcServer, that is fail-over to NOP, occurs on slf4j versions 1.6.0 and later. Make sure that you are using slf4j-api-1.6.x.jar on all platforms and that no older version of slf4j-api is placed on the class path.
Here are my 5 cents...
I had the same issues while running tests. So I've fixed it by adding an implementation for the test runtime only. I'm using gradle for this project.
// https://mvnrepository.com/artifact/ch.qos.logback/logback-classic
testRuntimeOnly group: 'ch.qos.logback', name: 'logback-classic', version: '1.2.3'
I know this post is a little old, but in case anyone else runs into this problem:
Add slf4j-jdk14-X.X.X.jar to your CLASSPATH (where X.X.X is the version number - e.g. slf4j-jdk14-1.7.5.jar).
HTH Peter
put file slf4j-log4j12-1.6.4.jar in the classpath will do the trick.
Source: Stackoverflow.com