正如标题所述，我正在尝试使用 Whiteboard 来托管我的 VaadinServlet。在多次尝试使用其他嵌入式 servlet 容器（如 Jetty 和 Grizzly）失败后，我在这里遇到了这个解决方案，由 Bndtools 人 Peter 本人编写。我试过自己实现这个，但我遇到了一个我自己无法解决的错误：
[test.client.ui.ClientUI$ClientServlet(4)] Error during instantiation of the implementation object
java.lang.InstantiationException: test.client.ui.ClientUI$ClientServlet: test.client.ui.ClientUI$ClientServlet.<init>()
Caused by: org.apache.felix.log.LogException: java.lang.InstantiationException: test.client.ui.ClientUI$ClientServlet
at java.lang.Class.newInstance(Class.java:427)
at org.apache.felix.scr.impl.manager.SingleComponentManager.createImplementationObject(SingleComponentManager.java:253)
at org.apache.felix.scr.impl.manager.SingleComponentManager.createComponent(SingleComponentManager.java:127)
at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(SingleComponentManager.java:871)
at org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(SingleComponentManager.java:838)
at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:850)
at org.apache.felix.scr.impl.manager.AbstractComponentManager.enable(AbstractComponentManager.java:419)
at org.apache.felix.scr.impl.config.ConfigurableComponentHolder.enableComponents(ConfigurableComponentHolder.java:376)
at org.apache.felix.scr.impl.BundleComponentActivator.initialize(BundleComponentActivator.java:172)
at org.apache.felix.scr.impl.BundleComponentActivator.<init>(BundleComponentActivator.java:120)
at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:258)
at org.apache.felix.scr.impl.Activator.access$000(Activator.java:45)
at org.apache.felix.scr.impl.Activator$ScrExtension.start(Activator.java:185)
at org.apache.felix.utils.extender.AbstractExtender.createExtension(AbstractExtender.java:259)
at org.apache.felix.utils.extender.AbstractExtender.modifiedBundle(AbstractExtender.java:232)
... 17 more
Caused by: java.lang.NoSuchMethodException: test.client.ui.ClientUI$ClientServlet.<init>()
at java.lang.Class.getConstructor0(Class.java:3082)
at java.lang.Class.newInstance(Class.java:412)
at org.apache.felix.scr.impl.manager.SingleComponentManager.createImplementationObject(SingleComponentManager.java:253)
at org.apache.felix.scr.impl.manager.SingleComponentManager.createComponent(SingleComponentManager.java:127)
at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(SingleComponentManager.java:871)
at org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(SingleComponentManager.java:838)
at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:850)
at org.apache.felix.scr.impl.manager.AbstractComponentManager.enable(AbstractComponentManager.java:419)
at org.apache.felix.scr.impl.config.ConfigurableComponentHolder.enableComponents(ConfigurableComponentHolder.java:376)
at org.apache.felix.scr.impl.BundleComponentActivator.initialize(BundleComponentActivator.java:172)
at org.apache.felix.scr.impl.BundleComponentActivator.<init>(BundleComponentActivator.java:120)
at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:258)
at org.apache.felix.scr.impl.Activator.access$000(Activator.java:45)
at org.apache.felix.scr.impl.Activator$ScrExtension.start(Activator.java:185)
at org.apache.felix.utils.extender.AbstractExtender.createExtension(AbstractExtender.java:259)
... 18 more
我添加了空构造函数只是为了看看它们是否改变了任何东西，但没有。
ClientUI 和 ClientServlet 类：
public class ClientUI extends UI
{
public ClientUI()
{
//Empty constructor.
}
@Override
public void init(VaadinRequest request)
{
//Typical UI initialization.
}
}
@VaadinServletConfiguration(productionMode = false, ui = ClientUI.class)
@Component(provide = Servlet.class, properties = {"alias=/test"}, immediate = true)
public class ClientServlet extends VaadinServlet
{
// Empty class. This class uses the annotations for servlet configuration instead of a web.xml.
public ClientServlet()
{
// Empty constructor.
}
}
关于如何停止此错误并使 servlet 启动并运行的任何想法？
编辑：新错误！下面评论的 Steffen 指出我可能需要将 servlet 类移动到顶级类，而我很可能确实需要这样做，但现在我明白了：
org.osgi.framework.ServiceException: Service cannot be cast: javax.servlet.Servlet
Caused by: org.apache.felix.log.LogException: org.osgi.framework.ServiceException: Service cannot be cast: javax.servlet.Servlet
at org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(ServiceRegistrationImpl.java:344)
at org.apache.felix.framework.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:231)
at org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:327)
at org.apache.felix.framework.Felix.getService(Felix.java:3574)
at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:468)
at org.osgi.util.tracker.ServiceTracker.addingService(ServiceTracker.java:411)
at org.apache.felix.http.whiteboard.internal.tracker.AbstractTracker.addingService(AbstractTracker.java:35)
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerAdding(ServiceTracker.java:932)
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerAdding(ServiceTracker.java:864)
at org.osgi.util.tracker.AbstractTracked.trackAdding(AbstractTracked.java:256)
at org.osgi.util.tracker.AbstractTracked.track(AbstractTracked.java:229)
at org.osgi.util.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:894)
at org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:943)
at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:794)
at org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(EventDispatcher.java:544)
... 12 more
此外，这个问题最终可能会被删除。我正在查看这个 Vaadin/OSGi EnRoute 示例，它可以满足我的需要，并且我已经确认它可以工作。我可能只是将示例提供程序和 API 用于应用程序或创建类似的东西。我暂时把这个问题搁置一旁，只是为了提供互联网知识，看看是否有人可以回答！