I'm working on a basic Java project to make me more comfortable with the language (I've just started learning), and have come across a problem when trying to use a 3rd party library - I'm trying to use Apache's Lang library. I'm not using Eclipse to write my program, which I believe has a tool which makes it easy to use 3rd party libraries, so I'm not sure how I can use this library. When I try to use it, the 2 errors I receive are 'error: package org.apache.commons.lang3 does not exist', and 'error: cannot find symbol' on the line in which I call the StringUtils class (part of the Lang library). How can I use the library? (I am definitely a beginner in Java).