Question

我们使用firebird，gwt（DATANUCLEUS，persistence objet）开发Web Applicaiton。

Map<String, String> props = new HashMap<String, String>();
        props.put("javax.jdo.PersistenceManagerFactoryClass",
                "org.datanucleus.api.jdo.JDOPersistenceManagerFactory");
        props.put("javax.jdo.option.ConnectionDriverName",
                "org.firebirdsql.jdbc.FBDriver");               
        props.put("javax.jdo.option.ConnectionURL",             "jdbc:firebirdsql://localhost/D:/ XXX fdb");
        props.put("javax.jdo.option.ConnectionUserName", "SYSDBA");
        props.put("javax.jdo.option.ConnectionPassword", "masterkey");
        props.put("javax.jdo.option.NontransactionalRead", "true");
        props.put("javax.jdo.option.NontransactionalWrite", "true");
        props.put("javax.jdo.option.RetainValues", "true");
        props.put("datanucleus.autoCreateSchema", "true");
        props.put("datanucleus.query.sql.allowAll", "true");
        pmfInstance = JDOHelper.getPersistenceManagerFactory(props);}
    private PMF() {
    }
    public static PersistenceManagerFactory getFactory() {
        return pmfInstance;
    }
    public static PersistenceManager getManager() {
        return pmfInstance.getPersistenceManager();
    }}}

在JDO类中，我们有这个函数，其中Zone是“类JDO”：

public static  List<Zone> queryAllZone() {

        PersistenceManager pm = PMF.getManager();
        Zone result =null;
        List<Zone> ListResult = null;//new ArrayList<Zone>();

        try {
            Query queryJDOQL =pm.newQuery(Zone.class, ***"ID_Zone > value"***);

            queryJDOQL.declareParameters("int value");

            ListResult =        (List<Zone>) queryJDOQL.execute(0);
        } finally {
            pm.close();
        }
    return  ListResult;
    }

我有结果错误：

Starting Jetty on port 0
   [WARN] Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.util.List com.exatelys.superviser.client.common.ZoneService.getAllZone()' threw an unexpected exception: javax.jdo.JDOUserException: Exception thrown while loading remaining rows of query
NestedThrowables:
javax.jdo.JDODataStoreException: Failed to read the result set : GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
NestedThrowables:
org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:389)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:579)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    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:487)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:324)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
Caused by: javax.jdo.JDOUserException: Exception thrown while loading remaining rows of query
NestedThrowables:
javax.jdo.JDODataStoreException: Failed to read the result set : GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
NestedThrowables:
org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
    at org.datanucleus.api.jdo.JDOAdapter.getUserExceptionForException(JDOAdapter.java:1139)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.closingConnection(ForwardQueryResult.java:272)
    at org.datanucleus.store.query.AbstractQueryResult.disconnect(AbstractQueryResult.java:107)
    at org.datanucleus.store.rdbms.query.AbstractRDBMSQueryResult.disconnect(AbstractRDBMSQueryResult.java:68)
    at org.datanucleus.store.rdbms.query.JDOQLQuery$2.managedConnectionPreClose(JDOQLQuery.java:718)
    at org.datanucleus.store.rdbms.ConnectionFactoryImpl$ManagedConnectionImpl.close(ConnectionFactoryImpl.java:510)
    at org.datanucleus.store.connection.AbstractManagedConnection.release(AbstractManagedConnection.java:77)
    at org.datanucleus.store.rdbms.ConnectionFactoryImpl$ManagedConnectionImpl.release(ConnectionFactoryImpl.java:347)
    at org.datanucleus.store.rdbms.query.JDOQLQuery.performExecute(JDOQLQuery.java:834)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1786)
    at org.datanucleus.store.query.Query.executeWithArray(Query.java:1672)
    at org.datanucleus.api.jdo.JDOQuery.execute(JDOQuery.java:243)
    at com.exatelys.superviser.server.jdo.Zone.queryAllZone(Zone.java:163)
    at com.exatelys.superviser.server.ZoneServiceImpl.getAllZone(ZoneServiceImpl.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561)
    ... 22 more
Caused by: javax.jdo.JDODataStoreException: Failed to read the result set : GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
NestedThrowables:
org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
    at org.datanucleus.api.jdo.JDOAdapter.getDataStoreExceptionForException(JDOAdapter.java:1150)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.nextResultSetElement(ForwardQueryResult.java:209)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult$QueryResultIterator.next(ForwardQueryResult.java:379)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.processNumberOfResults(ForwardQueryResult.java:137)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.advanceToEndOfResultSet(ForwardQueryResult.java:158)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.closingConnection(ForwardQueryResult.java:260)
    ... 39 more
Caused by: org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
    at org.firebirdsql.jdbc.FBStatementFetcher.fetch(FBStatementFetcher.java:206)
    at org.firebirdsql.jdbc.FBStatementFetcher.next(FBStatementFetcher.java:137)
    at org.firebirdsql.jdbc.AbstractResultSet.next(AbstractResultSet.java:273)
    at org.datanucleus.store.rdbms.datasource.dbcp.DelegatingResultSet.next(DelegatingResultSet.java:207)
    at org.datanucleus.store.rdbms.datasource.dbcp.DelegatingResultSet.next(DelegatingResultSet.java:207)
    at org.datanucleus.store.rdbms.datasource.dbcp.DelegatingResultSet.next(DelegatingResultSet.java:207)
    at org.datanucleus.store.rdbms.query.ForwardQueryResult.nextResultSetElement(ForwardQueryResult.java:191)
    ... 43 more
Caused by: org.firebirdsql.gds.GDSException: Dynamic SQL Error
SQL error code = -504
Invalid cursor reference
    at org.firebirdsql.gds.impl.wire.AbstractJavaGDSImpl.readStatusVector(AbstractJavaGDSImpl.java:2092)
    at org.firebirdsql.gds.impl.wire.AbstractJavaGDSImpl.receiveResponse(AbstractJavaGDSImpl.java:2042)
    at org.firebirdsql.gds.impl.wire.AbstractJavaGDSImpl.iscDsqlFetch(AbstractJavaGDSImpl.java:1322)
    at org.firebirdsql.gds.impl.GDSHelper.fetch(GDSHelper.java:265)
    at org.firebirdsql.jdbc.FBStatementFetcher.fetch(FBStatementFetcher.java:201)
    ... 49 more

当w使用==而不是＆gt;在表达式“ID_Zone == value”中，我们得到了很好的结果。但如果我们尝试获取一个列表（超过对象），我们总是有相同的问题。

更多，在eatch连接（使用PMF类）之后，我们将在B.D.D中有一个名为deletedxxxxx的新空表。你可以帮帮我!!!

Answer 1

问题在于Jaybird TYPE_FORWARD_ONLY结果集默认为CLOSE_CURSORS_AT_COMMIT，并且是按需提取的。

当没有使用显式事务时，DataNucleus在初始化（但不处理）结果集之后提交连接，结果ResultSet被关闭。

随后，DataNucleus关闭/释放（托管）连接，从而触发ResultSet的提取。这会导致错误，因为事务已提交且结果集已关闭。由于Jaybird中的bug，此ResultSet关闭不在本地“处理”，仅当请求到达服务器时，由于光标句柄不再有效而触发错误。由于同样的错误，看起来单项提取工作是偶然的。

我认为DataNucleus应该在提交时执行此提取，而不是在连接结束时执行。看起来它在使用显式事务时确实如此，但并非没有。

解决方法是：

使用显式交易
在连接字符串中指定defaultHoldable=true连接属性，以使结果集默认为HOLD_CURSORS_OVER_COMMIT
将抓取大小设置为急切：queryJDOQL.getFetchPlan().setFetchSize(FetchPlan.FETCH_SIZE_GREEDY);

注意：我使用Jaybird 2.2.4（最新发布的版本）对此进行了测试。

我已将此错误报告为http://www.datanucleus.org/servlet/jira/browse/NUCRDBMS-779（错误已修复，请参阅故障单中的最后评论）

firebird：SQL错误代码= -504游标引用无效

1 个答案: