Android Question Simple Library Compiler: "package does not exist"

I've used the tutorial for creating some simple B4A libraries without any problems. They didn't do much, I just wanted to make sure I understood how to do it.

Now I'm working on a real project and I've run into a snag. I downloaded the Apache Commons IO library and referenced it in my Eclipse project (Build Path > Configure Build Paths > Libraries > Add External JAR). I then imported it into my project:
I used the FileUtils class of this library in my project. Eclipse doesn't show any errors or warnings regarding the way I've used it but when I try to compile it with the Simple Library Compiler (great tool!), I get the following message:

Starting step: Compiling Java code.
javac 1.8.0_45
D:\eclipse_proj\forecast\src\com\frigginjiggy\forecast\Update.java:5: error: package org.apache.commons.io does not exist
import org.apache.commons.io.*;
^
1 error

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Can someone tell me if I've missed something, or done something wrong?