For OOXML to work you need the POI-OOXML jar which is separately packaged from the POI jar.
Download the POI-OOXML jar from the following location –
http://repo1.maven.org/maven2/org/apache/poi/poi-ooxml/3.11/poi-ooxml-3.11.jar
For Maven2 add the below dependency –
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.11</version>
</dependency>