查询数据库时出现Google App Engine getJDOExceptionForNucleusException错误

Question

我正在开发一个Google App Engine托管后端数据存储区的项目，我可以发送JSON请求通过我的网站点击它。

我有多个表（IE订单信息，优惠券等），只是创建了一个新表Session。我的想法是，我希望数据库存储会话ID，而不是使用Memcache来保存数据。我编写了代码来检查它，但每当我在数据库中搜索会话ID时，它都会返回一个错误：

org.datanucleus.api.jdo.NucleusJDOHelper getJDOExceptionForNucleusException: Exception thrown
Received a request to find an object of kind Session but the provided identifier is the String representation of a Key for kind Token

以下是我所指的此会话的数据库表的图片：

我对此感到困惑的问题是为什么这会成为一个问题，当我使用String作为主键对数据库执行的其他查询工作正常...任何人有任何想法？

完整错误输出：

org.datanucleus.api.jdo.NucleusJDOHelper getJDOExceptionForNucleusException: Exception thrown
Received a request to find an object of kind Session but the provided identifier is the String representation of a Key for kind Token
org.datanucleus.exceptions.NucleusFatalUserException: Received a request to find an object of kind Session but the provided identifier is the String representation of a Key for kind Token
    at com.google.appengine.datanucleus.EntityUtils.stringToInternalKey(EntityUtils.java:423)
    at com.google.appengine.datanucleus.EntityUtils.idToInternalKey(EntityUtils.java:218)
    at com.google.appengine.datanucleus.EntityUtils.idToInternalKey(EntityUtils.java:208)
    at com.google.appengine.datanucleus.DatastoreIdentityKeyTranslator.getKey(DatastoreIdentityKeyTranslator.java:32)
    at org.datanucleus.ObjectManagerImpl.newObjectId(ObjectManagerImpl.java:3443)
    at org.datanucleus.api.jdo.JDOPersistenceManager.newObjectIdInstance(JDOPersistenceManager.java:1618)
    at org.datanucleus.api.jdo.JDOPersistenceManager.getObjectById(JDOPersistenceManager.java:1740)
    at com.package.core.DataSourceMgr.getObjectById(DataSourceMgr.java:118)
    at com.package.service.SessionService.getSession(SessionService.java:39)
    at com.package.misc.TESTQueryDBForSessionID.execute(TESTQueryDBForSessionID.java:25)
    at com.package.batch.CronShell.doGet(CronShell.java:40)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    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$CachedChain.doFilter(ServletHandler.java:1166)
    at com.package.core.DataSourceFilter.doFilter(DataSourceFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
    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 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.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:257)
    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$RequestHandler.headerComplete(HttpConnection.java:923)
    at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
    at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:482)
    at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
    at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
    at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:234)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

显然，问题是双重的。

首先，系统出现了问题，我使用String作为主键（不知道为什么这个问题是一个问题而其他问题没有问题......）。将其切换为随机生成的长整数。

这解决了第一个问题，但随后又出现了第二个问题，当你有一个GAE数据存储区的主键/ ID时，你无法查询它。您必须使用Long（盒装版本，大写L）而不是很长时间才能工作。之后，能够删除数据存储区中的现有项目并上传新代码。

tl; dr - 如果有人再遇到过这个问题，请确保： 1）您正在使用某种类型的Long作为ID /主键 2）您在代码中使用Long（不长）：

public class Session extends BaseEntity {
    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Long id;
    //...
}

-Pat