(IF YOUR NOT USING MAVEN) Well in this scenario you will need to download the JAR files in zip, extract it and later add the External JAR files in the 'build-path' under the 'Classpath' section. Download the slf4j-api JAR and slf4j-simple JAR from the given website, yeah its not secure but its safe I have used it to download these JAR files when I run into the same problem, http://www.java2s.com/