title: Eclipse. ClassNotFoundException but I do know that class exists
body: <p>I added myLibrary.jar in project BuildPath and try to call static method from myLibrary.jar myClass but have exception:<br></p>
  
  <pre><code>Caused by: java.lang.NoClassDefFoundError: application/Application
      at rcp.handlers.RunGenerationHandler.execute(RunGenerationHandler.java:29)
      at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:294)
      at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:90)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
      ... 38 more
  Caused by: java.lang.ClassNotFoundException: application.Application cannot be found by rcp_1.0.0.qualifier
      at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:432)
      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:345)
      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:337)
      at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
      at java.lang.ClassLoader.loadClass(Unknown Source)
      ... 46 more
  </code></pre>
  
  <p>I'm sure that class exists in Library.
  I try to rebuild myLibrary.jar and add in project again but problem still stays.<br>
  Below is the code where I try to call static method from my class:</p>
  
  <pre><code>import application.Application;
  ...
  
  if (generationString != null){
      Application.main(generationString);
  }
  </code></pre>
  
  <p>Application - class in myLibrary.jar</p>
  
  <p><img src="https://i.stack.imgur.com/1nYH4.png" alt="Screenshot with package tree"></p>
  
  <p>ldl = myLibrary</p>
  
  <p><strong>UPDATE</strong><br>
  I'm really such a slowpoke=(<br>
  In RCP applications libraries attaching in MANIFEST.MF<br>
  Example:<pre>Bundle-ClassPath: .,/directory/myLibrary.jar</pre></p>