Exception in thread "main" java.lang.NoClassDefFoundError: org/xmlpull/v1/XmlPullParserFactory

I’m trying to create a basic server-side application which uses the Smack library to log into an Openfire server. I get the following exception when I try to compile and run:

Exception in thread “main” java.lang.NoClassDefFoundError: org/xmlpull/v1/XmlPullParserFactory

at org.jivesoftware.smack.SmackConfiguration.(SmackConfiguration.java:74)

at org.jivesoftware.smack.Connection.(Connection.java:118)

at org.jivesoftware.smack.ConnectionConfiguration.(ConnectionConfiguration.j ava:73)

Caused by: java.lang.ClassNotFoundException: org.xmlpull.v1.XmlPullParserFactory

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)

… 5 more

I’ve looked down into the smack.jar library, and I see that there is indeed not an XmlPullParserFactory class. Am I missing something? Has anyone else had this problem?