title: java.lang.NoClassDefFoundError
body: <p>I got "java.lang.NoClassDefFoundError" Exception when I want to use a certain jar file.</p>
  
  <pre><code>Exception in thread "main" java.lang.NoClassDefFoundError: .
  org/apache/http/client/ClientProtocolException
      at ?uk.org.taverna.server.client.connection.ConnectionFactory.getConnection(ConnectionFactory.java:63)
      at uk.org.taverna.server.client.Server.&lt;init&gt;(Server.java:99)
      at uk.org.taverna.server.client.Server.&lt;init&gt;(Server.java:126)
      at uk.org.taverna.server.client.Server.connect(Server.java:293)
      at uk.org.taverna.server.usage.ServerUsage.Usage(ServerUsage.java:24)
      at Test.main(Test.java:23)
  Caused by: java.lang.ClassNotFoundException: org.apache.http.client.ClientProtocolException
      at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
  </code></pre>
  
  <p>I import this jar file to jar library, when I call the method in that jar file I got this Exception. By the way, This jar file be wrote by myself, and I can run it correctly.
  I have no idea how to solve this problem, I am quite new in java.</p>
  
  <p>Thanks in advance.</p>
  
  <p>Sandy</p>