Vaadin：SubscriberExceptionHandler 上的 NoClassDefFoundError？

Question

尝试实现与 Dashboard demo 中相同类型的 Event 和 EventBus 内容，我在尝试运行应用程序时遇到此错误:

=================================================================
Vaadin is running in DEBUG MODE.
Add productionMode=true to web.xml to disable debug features.
To show debug window, add ?debug to your application URL.
=================================================================
Aug 31, 2015 3:06:08 PM com.vaadin.server.DefaultErrorHandler doDefault
SEVERE: 
java.lang.NoClassDefFoundError: com/google/common/eventbus/SubscriberExceptionHandler
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2472)
    at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:854)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1274)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1157)
    at info.chrismcgee.sky.scheduling.SchedulingUI.<init>(SchedulingUI.java:48)

SchedulingUI.java 中的第 48 行是：

private final SchedulingEventBus schedulingEventbus = new SchedulingEventBus();

（我基本上只是将所有 "Dashboard" 引用替换为 "Scheduling" 以符合我的网络应用程序。）当然，我仍在努力弄清楚这无济于事SchedulingEvent.java 和 SchedulingEventBus.java 的要点以及它们的工作原理。（还是新手。）

编辑 09/01/2015： 为了澄清我重命名的内容，这是我的 SchedulingEventBus.java 文件：

package info.chrismcgee.sky.event;

import info.chrismcgee.sky.scheduling.SchedulingUI;

import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.SubscriberExceptionContext;
import com.google.common.eventbus.SubscriberExceptionHandler;

/**
 * A simple wrapper for Guava event bus. Defines static convenience methods for
 * relevant actions.
 * 
 * @author Marketing
 *
 */
public class SchedulingEventBus implements SubscriberExceptionHandler {

    private final EventBus eventBus = new EventBus(this);

    public static void post(final Object event) {
        SchedulingUI.getSchedulingEventbus().eventBus.post(event);
    }

    public static void register(final Object object) {
        SchedulingUI.getSchedulingEventbus().eventBus.register(object);
    }

    public static void unregister(final Object object) {
        SchedulingUI.getSchedulingEventbus().eventBus.unregister(object);
    }

    @Override
    public void handleException(final Throwable exception,
            final SubscriberExceptionContext context) {

        exception.printStackTrace();
    }

}

Answer 1

将以下依赖项添加到 ivy.xml 文件：

<dependency org="com.google.guava" name="guava" rev="18.0"/>

我在尝试做完全相同的事情时遇到了完全相同的问题。这清除了 NoClassDefFoundError。

Vaadin：SubscriberExceptionHandler 上的 NoClassDefFoundError？

Vaadin: NoClassDefFoundError on SubscriberExceptionHandler?

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