JSF / XSP NoClassDefFoundError

Question

我正在尝试设置一个基于JSF的XPage应用程序。在其中一个控制器中，我试图使用全局定义的bean：

<managed-bean>
    <managed-bean-name>servicePositionBean</managed-bean-name>
    <managed-bean-class>beans.ServicePositionBean</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
  </managed-bean>

我认为它失败的地方：

FacesContext context = FacesContext.getCurrentInstance();
return context.getApplication().getVariableResolver().resolveVariable(context, "servicePositionBean");

我得到的错误：

javax.faces.el.EvaluationException: java.lang.NoClassDefFoundError: beans/ServicePositionBean
    com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:142)
    com.ibm.xsp.component.UIViewRootEx.initBeforeContents(UIViewRootEx.java:1621)
    com.ibm.xsp.page.compiled.AbstractCompiledPage.initComponent(AbstractCompiledPage.java:333)
    com.ibm.xsp.page.compiled.AbstractCompiledPage.createTree(AbstractCompiledPage.java:256)
    com.ibm.xsp.page.compiled.AbstractCompiledPage.createViewRoot(AbstractCompiledPage.java:167)
    com.ibm.xsp.application.ViewHandlerExImpl._createViewRoot(ViewHandlerExImpl.java:521)
    com.ibm.xsp.application.ViewHandlerExImpl.createViewRoot(ViewHandlerExImpl.java:567)
    com.ibm.xsp.application.ViewHandlerExImpl.doCreateView(ViewHandlerExImpl.java:142)
    com.ibm.xsp.application.ViewHandlerEx.createView(ViewHandlerEx.java:90)

我100％确定bean是在目录中正确定义的。