Java 503错误ObjectifyService NoClassDefFoundError

我在api资源管理器中遇到GAE问题。我试图使用objectify保存到数据存储，但出现以下错误：

{
"error": {
"message": "java.lang.NoClassDefFoundError: Could not initialize class Project.service.OfyService",
"code": 503,
"errors": [
{
"domain": "global",
"reason": "backendError",
"message": "java.lang.NoClassDefFoundError: Could not initialize class Project.service.OfyService"
}
]
}
}

我试着用谷歌搜索一下，但结果却是空手而归。我对GAE真的很陌生，对Java也有点陌生。以下是intelliJ控制台中显示的内容：

java.lang.NoClassDefFoundError: Could not initialize class Project.service.OfyService
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:191)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestrict  ed(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at Project.saveProfile(ProjectApi.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:491)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

Jan 25, 2015 12:39:14 PM com.google.api.server.spi.SystemService invokeServiceMethod
SEVERE: Could not initialize class Project.service.OfyService
java.lang.NoClassDefFoundError: Could not initialize class Project.service.OfyService
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:191)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at Project.saveProfile(ProjectApi.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:491)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

以下是我的服务：

public class OfyService {
/**
 * This static block ensure the entity registration.
 */
static {
    factory().register(Game.class);
    factory().register(Platform.class);
    factory().register(Profile.class);
}

/**
 * Use this static method for getting the Objectify service object in order to make sure the
 * above static block is executed before using Objectify.
 * @return Objectify service object.
 */
public static Objectify ofy() {
    return ObjectifyService.ofy();
}

/**
 * Use this static method for getting the Objectify service factory.
 * @return ObjectifyFactory.
 */
public static ObjectifyFactory factory() {
    return ObjectifyService.factory();
}
}

我的api：

@ApiMethod(name = "saveProfile", path = "profile", httpMethod = HttpMethod.POST)
public Profile saveProfile(final User user, ProfileForm profileForm)
        throws UnauthorizedException {
    if(user == null)
    {
        throw new UnauthorizedException("Authorization Required.");
    }

    String mainEmail = user.getEmail();
    String userId = user.getUserId();
    String displayName = profileForm.getDisplayName();
    Profile profile = new Profile(userId, displayName, mainEmail);
    ofy().save().entity(profile).now();
    return profile;
}

GAE SDK版本：1.9.17

目标化版本：5.1.4

---

我尝试了多种不同的版本组合，看看它是否是SDK的

NoClassDefFound

在找不到类或无法加载类时抛出。因此，如果静态初始化失败，您将得到此错误。在您的情况下，未能加载的类是您自己的

ObjectifyService

，因此

factory（）.register（…）

可能引发异常

为了帮助诊断问题，您可以将静态init块中的所有注册包装在try/catch中，记录异常/stacktrace，然后重试。堆栈跟踪将有助于识别导致异常的配置文件、游戏和平台

---

也没有理由这样包装ObjectifyService，如果您使用依赖项注入，您可以在启动时使用标准DI模式注册类，这样任何异常都会像正常情况一样从启动中流出。

不要忘记为持久化对象声明

@Entity

和

@Id

，以获取其唯一标识符

@Entity
public class Profile {
    @Id
    Long userId;
    String displayName;
    String mainEmail;
    ...
    }

---

我只是想把这句话写进一个答案，因为我也只是花了几个小时来解决与OP相同的问题+解决方案，直到后来我才费心阅读评论=p

把这个放在这里，让人们更清楚地看到：

---

问题是我注册的所有实体上都没有

@Entity

太棒了！非常感谢。不过，对智者来说，在调试模式下逐步完成这一过程需要花费很长时间，因为有大量的工作正在进行。我的主要问题是，我试图注册的类中没有@Entity。我打算以后再做这些，然后把它们都安排好，我只是想让其中一门课开始工作。另外，我不明白你在最后一段中的意思，我将不得不用谷歌搜索它，看看我是否能找出那一部分。最后，根据我在这里读到的另一篇文章，我将

寄存器

移动到每个类。感谢您的帮助。在注释中解释有点困难，但是如果您可以在其他任何地方注册非静态init块的类，您应该这样做。例如，使用spring，您可以在创建存储库或服务类时这样做。更多信息请参见这里：是的，我昨晚看了那个文档，它确实揭示了我做错了什么。非常感谢！！