ClassNotFoundException: org.slf4j.LoggerFactory

Better to always download as your first try, the most recent version from the developer's site

I had the same error message you had, and by downloading the jar from the above (slf4j-1.7.2.tar.gz most recent version as of 2012OCT13), untarring, uncompressing, adding 2 jars to build path in eclipse (or adding to classpath in comand line):

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

I was able to run my program.

Try downloading jar from here

You can find, it holds the class you need.

EDIT

Seems like the website has changed its structure. You need to choose which jar file you need for your project.

For slf4j-api jar file for latest version as of now, please visit this link

For slf4j-simple jar file for latest version as of now, please visit this link

i know this is an old Question , but i faced this problem recently and i looked for it in google , and i came across this documentation here from slf4j website .

as it describes the following :

This error 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.

Hope that will help someone .