title: how to open an existing .xlsx file using apache poi
body: <p>I have aproblem in apache poi.</p>
  
  <p>The problem is, I want to open an existing .xlsx file using apache poi in my java program.while doing, java raising below mentioned exception...</p>
  
  <p>Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException</p>
  
  <pre><code>    Caused by: java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException
      at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
      ... 2 more
  </code></pre>
  
  <p>I am using excel 2003 and just convert my .xls to .xlsx(Excel 2007 workbook) file using saveas command in excel.</p>