the problem is as such. i've imported the right packages sufficient to construct an XSSFworkbook object. i added the right jars in eclipse so it will be able to load these imports: import org.apache.poi.ss.usermodel.*; import org.apache.poi.xssf.usermodel.*; but then when i do the following: Workbook wb = new XSSFWorkbook(); FileOutputStream fileOut = new FileOutputStream("workbook123.xlsx"); wb.write(fileOut); fileOut.close(); it is able to run smooth from the eclips point of view however in the runtime i get this error: at POIWrite.main(POIWrite.java:13) Caused by: java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 1 more i thought it was a problem of package loading but i saw two other dudes who ran into this exact error, all of them in eclipse. http://www.mail-archive.com/user@xmlbeans.apache.org/msg01944.html http://forums.sun.com/thread.jspa?threadID=5389309 btw with HSSFworkbook things run smooth as smooth can get. anyway, i hope this but will be fixed next version cause eclipse is my favorite environment for java.
You need to import all the dependencies too. They're all in the binary download, and listed in http://poi.apache.org/overview.html