从Objectify v5到v6 ObjectifyService.init（）的转换不会引发ClassDefFoundError

Question

package org.chemvantage;

import java.util.Date;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import com.googlecode.objectify.ObjectifyService;

public class EntityRegistrar implements ServletContextListener {

     public void contextInitialized(ServletContextEvent servletContextEvent) {
        System.out.println("Starting up: " + new Date());

        ObjectifyService.init();   // line 15

        ObjectifyService.register(Assignment.class);
        ObjectifyService.register(BLTIConsumer.class);
    }
}

servlet中未捕获的异常

java.lang.noClassDefFounderror：com/googlecode/objectify/objectifyService at org.chemvantage.entityRegistrar.contextInitialized（entityRegistrar.java:15)at org.eclipse.jetty.server.handler.contextHandler.callContextInitialized（contextHandler.java:843)at org.eclipse.jetty.servlet.servlet.servlet.callContextInitialized（.servletContextHandler.startContext(servletContextHandler.java:345)在org.eclipse.jetty.webapp.webappContext.startWebApp(webappContext.java:1406)在com.google.apphosting.runtime.jetty9.appEngineWebAppContext.java:175)在org.eclipse.jetty.webapp.webappContext.startWebApp(appEngineWebAppContext.java:175)在doStart(servletContextHandler.java:262)位于org.eclipse。jetty.webapp.webappContext.doStart(webappContext.java:522)在com.google.apphosting.runtime.jetty9.appEngineWebAppContext.doStart(appEngineWebAppContext.java:120)在org.eclipse.jetty.util.component.abstractLifecycle.start(abstractLifecycle.java:68)在AP.java:178)在com.google.apphosting.runtime.jetty9.jettyServletEngineAdapter.ServiceRequest(jettyServletEngineAdapter.java:120)在com.google.apphosting.runtime.javaruntime$requestrunnable.dispatchServletRequest(javaruntime.javatch:722)在com.google.apphosting.runtime.javaruntime$requestrunnable.dispatchRequest.runtime.javaruntime$NullSandBoxRequestRunnable.run(javaruntime.java:847)at com.google.apphosting.runtime.threadgrouppool$poolentry.run(threadgrouppool.java:270)at java.lang.thread.run(thread.java:748)

Answer 1

好的，感谢任何代表我为这件事挠头的人。我想我找到了答案：

为了处理异步datastore操作（特别是留在后台的ofy().sa ve（）操作），必须包含以下Java类，它扩展了ObjectifyFilter。

package org.chemvantage;

import javax.servlet.annotation.WebFilter;

import com.googlecode.objectify.ObjectifyFilter;

/**
 * Filter required by Objectify to clean up any thread-local transaction contexts and pending
 * asynchronous operations that remain at the end of a request.
 */
@WebFilter(urlPatterns = {"/*"})
public class ObjectifyWebFilter extends ObjectifyFilter {}

这是对web.xml文件中ObjectifyFilter所需定义的补充。

<web-app>
  <filter>
    <filter-name>ObjectifyFilter</filter-name>
    <filter-class>com.googlecode.objectify.ObjectifyFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>ObjectifyFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>