Download zip file from the following link:

http://download.nextag.com/apache/poi/release/bin/

Then put the poi-3.2-FINAL-20081019.jar,poi-contrib-3.2-FINAL-20081019.jar and poi-scratchpad-3.2-FINAL-20081019.jar files into the following path:

\Java\jdk1.7.0\lib
\Java\jdk1.7.0\jre\lib
\Java\jdk1.7.0\jre\lib\ext
\Java\jre7\lib
\Java\jre7\lib\ext

Then restart the compiler and try the examples from the following link:

Apache POI Examples