you can download the commons IO File utility jar using the link below,
http://apache.cs.utah.edu//commons/io/binaries/commons-io-2.4-bin.zip
and slf4j jar using the link,
http://www.slf4j.org/dist/slf4j-1.7.5.zip.
To add the jar to your eclipse project do, Right click on project -> Build path -> Configure Build Path -> java build path -> Libraries -> Add external jar browse the jar path and add all the jar you need. Also, add jars to the lib folder of your project present at WEB-INF/lib