查询列表上的Collections.sort（）抛出java.lang.UnsupportedOperationException：查询结果集不可修改

时间：2016-06-20 10:57:06

标签： java sorting jdo datanucleus unsupportedoperation

我有这个JDO服务返回public List<Order> getOnGoingOrders() { List<Order> orderList = null; JDOPersistenceManager pm = (JDOPersistenceManager) persistenceManager.getPM(); try { Query<Order> q = pm.newQuery(Order.class); q.setFilter("orderStatus != 'COMPLETED' && orderStatus != 'CANCELLED'"); q.setOrdering("orderPlacedTime desc"); orderList = (List<Order>) q.execute(); } catch (Exception e) { e.printStackTrace(); } return orderList; } ：

Collections#sort()

当前端调用 com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException SEVERE: Error Rendering View[/index.xhtml] java.lang.UnsupportedOperationException: Query result sets are not modifiable at org.datanucleus.store.query.AbstractQueryResultIterator.set(AbstractQueryResultIterator.java:86) at java.util.List.sort(List.java:482) at java.util.Collections.sort(Collections.java:175) at org.primefaces.component.datatable.feature.SortFeature.singleSort(SortFeature.java:148) at org.primefaces.component.datatable.feature.SortFeature.encode(SortFeature.java:106) at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:80) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:920) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1863) at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:582) at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183) at org.primefaces.component.api.UIData.visitTree(UIData.java:827) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) at javax.faces.component.UIForm.visitTree(UIForm.java:371) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) at org.primefaces.component.api.UITabPanel.visitTree(UITabPanel.java:920) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1700) at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:403) at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:322) at org.primefaces.context.PrimePartialViewContext.processPartial(PrimePartialViewContext.java:57) at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:219) at org.omnifaces.context.OmniPartialViewContext.processPartial(OmniPartialViewContext.java:139) at javax.faces.component.UIViewRoot.encodeChildren(UIViewRoot.java:1004) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856) at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:432) at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:134) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) at org.omnifaces.viewhandler.NoAutoGeneratedIdViewHandler.renderView(NoAutoGeneratedIdViewHandler.java:93) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219) at org.apache.deltaspike.jsf.impl.listener.request.DeltaSpikeLifecycleWrapper.render(DeltaSpikeLifecycleWrapper.java:111) at javax.faces.lifecycle.LifecycleWrapper.render(LifecycleWrapper.java:92) at org.apache.deltaspike.jsf.impl.listener.request.JsfClientWindowAwareLifecycleWrapper.render(JsfClientWindowAwareLifecycleWrapper.java:160) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:659) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) 时，我得到以下异常：

ReqPhone

这是如何引起的？如何解决？

2 个答案:

答案 0 :(得分：4)

我不知道您正在使用的持久性管理器（JDO），但似乎查询返回的结果列表不可修改（您可以在JDO文档中阅读该内容）。

尝试创建一个新的List，使用查询结果执行addAll（），并使用该List。

答案 1 :(得分：0)

我认为这不是Primefaces / JSF问题。排序函数对此来说太微不足道了。你的xhtml第一眼看上去很好。

尝试将列表初始化为空列表，如

private ArrayList<Order> orders = new ArrayList<order>()

..在加载数据之前。因此，您可以确保永远不会有“空列表”。 此外，您是否检查过数据是否已正确加载？否则，尝试按q.getResultList()检索数据。在我的情况下，我一直使用这种方法，没有任何问题。 另一个提示：尝试将检索到的列表从数据库复制到带有addAll()的额外返回列表（如安全副本）并返回该列表。

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