title: What causes java.lang.ClassNotFoundException in running code
body: <p>This error : <code>java.lang.ClassNotFoundException : javax.xml.soap.SoapException</code></p>
  
  <p>I can see javax.xml.soap.SoapException is on the classpath so what could be causing this error ? </p>
  
  <p>In more general terms how could a <code>java.lang.ClassNotFoundException</code> be thrown in running code, should the compiler not catch this error ? The only situation I could this occurring is that if a jar was built using a library and the library that jar depends on is not on the classpath when using the jar.</p>