Java. Lang. Noclassdeffounderror: Org. Slf4J. Loggerfactory

Add a SLF4J implementation (as you only have its API):

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.26</version>
</dependency>

You have to provide one of the various SLF4J implementation .jar files in the classpath, as well as the interface .jar file. This is documented.

Download slf4j-1.7.5.zip

It holds different jar files.

Go to -> Integration folder after extracting zip and include following jar files

1. slf4j-api-2.0.99
2. slf4j-simple-1.6.99
3. junit-3.8.1

Right click on project properties and follow below steps Project Properties" --> "Deployment Assembly", adding "Java Build Path Entries -> Maven Dependencies

I tried other solutions and the exception didn't go away. So I decompiled the entire jose4j 0.6.5 jar with a Java Decomplier and look at its pom.xml.

I realised it has a specific dependency on slf4j-api, version 1.7.21:

So in my project's pom.xml, I added the exact same dependency, updated my Maven project so that it downloads this jar into my repository and the exception was gone.

However it may bring up another error caused by slf4j itself:

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

To overcome this issue, I added the following into my project's pom.xml. So altogether you need to add the following to your pom.xml and my jose4j ran without anymore issues:

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.21</version>
</dependency>   

<dependency>
   <groupId>org.slf4j</groupId>
   <artifactId>slf4j-simple</artifactId>
   <version>1.6.4</version>
</dependency>

Remember to update your Maven project after amending your pom.xml.

(Right-click Project folder in Eclipse -> Maven -> Update Project..)

I also had the similar problem. I had a maven project and was testing rabbitmq. Firstly it showed me the similar error then I added all the SLF4J dependencies in the maven project and then error changed to "Maven SLF4J: Class path contains multiple SLF4J bindings". Here is the complete list of dependencies from pom.xlm

<dependencies>
    <dependency>
        <groupId>com.rabbitmq</groupId>
        <artifactId>amqp-client</artifactId>
        <version>4.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.0</version>
    </dependency>
    <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-simple</artifactId>
       <version>1.7.21</version>
       <scope>compile</scope>
    </dependency>
</dependencies> 

It worked finally.

I was facing a similar issue and below line fixed the issue for me.

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

Edit: I realized that I was using spring boot and the version of the dependency was getting pulled from spring-boot-starter-parent.

You can use bellow dependency

<dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.7.7</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.7</version>
    </dependency>

Add the following jars to the class path or lib folder

1. slf4j-api-1.7.2.jar
2. slf4j-jdk14-1.7.2.jar

The perfect solution which works undoubtedly is to just add these packages to your app:

after adding so you may encounter following WARNING which you can simply ignore!

SLF4J: No SLF4J providers were found. SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See for further details.

credits:

This error occurs because of referenced jars are not checked in our project's order and export tab.

Choose Project ->ALT+Enter->Java Build Path ->Order and Export->check necessary jar files into your project.

Finally clean your project and run.It will run successfully.

To be more specific if you are missing the class com.vaadin.external.org.slf4j.LoggerFactory add the below dependency.

<dependency>
    <groupId>com.vaadin.external.slf4j</groupId>
    <artifactId>vaadin-slf4j-jdk14</artifactId>
    <version>1.6.1</version>
</dependency>

If you are missing any other org.slf4j.LoggerFactory, just go to Maven central class name search and search for the exact class name to determine what exact dependency you are missing.

When we use the slf4j api jar, we need any of the logger implementations like log4j. On my system, we have the complete set and it works fine.

1. slf4j-api-1.5.6.jar
2. slf4j-log4j12-1.5.6.jar
3. **log4j-1.2.15.jar**

I believe the answer is outlined on the slf4j web-site (Failed to load class org.slf4j.impl.StaticLoggerBinder)

For a very quick solution I suggest adding no-operation (NOP) logger implementation (slf4j-nop.jar)

For example, if using maven:

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

use maven it will download all the required jar files for you.

in this case you need the below jar files:

slf4j-log4j12-1.6.1.jar slf4j-api-1.6.1.jar

These jars will also depend on the cassandra version which you are running. There are dependencies with cassandra version , jar version and jdk version you use.

You can use : jdk1.6 with : cassandra 1.1.12 and the above jars.

make sure your MANIFEST.MF contains the name of the referenced jar in my application was slf4j-api-*. jar.

You need slf4j-api library. For most cases only slf4j-api and slf4j-jkd14 are only required:

Here you can download the version 1.7.2:

slf4j-api-1.7.2.jar
slf4j-jkd14-1.7.2jar

If you need an example to see how these are used, refers to this tutorial:

All the code for the tutorial is available

get the compatible version of this jar slf4j-jdk14 and add it as a dependency. this solved the problem for me.

You need slf4j-api library and slf4j-log4j12-1.7.25 jar. Copy this jars in your project-> WEBINF-> lib folder and in tomcat server lib folder to execute successfully.

When you copy dependency from maven repository there is:

<scope>test</scope>

Try to remove it from dependencies in pom.xml like this.

<!--  -->
<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.2.3</version>
</dependency>

This works for me. I hope it would be helpful for someone else.

this worked for me /properties/maven uncheck resolve dependencies from Workspace projects.

First, check the dependency hierarchy than to exclude all slf4j jars from other dependencies and add separate slf4j as dependencies.

If you are facing java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory

Add slf4j-log4j12 jar in the library folder of the project