title: Java and error in Cast programming--AttrCertExample?
body: <p>When i run my program, the console gives me an error:</p>
  
  <blockquote>
    <p>java.lang.NoClassDefFoundError: org/bouncycastle/x509/examples/AttrCertExample</p>
  </blockquote>
  
  <p>What's my problem?</p>