Hi everybody,

I'm getting an exception when I attempt to save a Date field
using the component datebox with conditional binding:

<datebox value="@load(vm.startDate) @save(vm.startDate, before='save')" />

Debugging the code, when it's comparing a java.sql.Timestamp object and a java.util.Date object then it throws the Exception.

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Jun 05, 2018 5:44:04 PM org.zkoss.zk.ui.impl.UiEngineImpl handleError
SEVERE:
java.lang.IllegalStateException: can only add one element
at org.zkoss.zkmax.bind.impl.SingleObjectSet.add(SingleObjectSet.java:43)
at org.zkoss.zkmax.bind.impl.AllocUtilEx.addLinkedHashSet(AnnotateBinderEx.java:131)
at org.zkoss.zkmax.bind.impl.TrackerImplEx.addBeanMap(TrackerImplEx.java:126)
at org.zkoss.bind.tracker.impl.TrackerImpl.tieValue(TrackerImpl.java:343)
at org.zkoss.bind.xel.zel.BindELResolver.tieValue(BindELResolver.java:285)
at org.zkoss.zkmax.bind.impl.BindELResolverEx.tieValue(BindELResolverEx.java:143)
at org.zkoss.bind.xel.zel.BindELResolver.getValue(BindELResolver.java:154)
at org.zkoss.zel.impl.parser.AstValue.getValue(AstValue.java:188)
at org.zkoss.zel.impl.ValueExpressionImpl.getValue(ValueExpressionImpl.java:184)
at org.zkoss.zkmax.bind.impl.ValueExpressionImplEx.getValue(ValueExpressionImplEx.java:52)
at org.zkoss.xel.zel.ELXelExpression.evaluate(ELXelExpression.java:41)
at org.zkoss.zkmax.bind.impl.BindEvaluatorXImplEx$LazyBindXelExpression.evaluate(BindEvaluatorXImplEx.java:124)
at org.zkoss.bind.impl.BindEvaluatorXImpl.getValue(BindEvaluatorXImpl.java:46)
at org.zkoss.bind.impl.LoadPropertyBindingImpl.load(LoadPropertyBindingImpl.java:58)
at org.zkoss.bind.impl.BinderImpl.doPropertyChange0(BinderImpl.java:460)
at org.zkoss.bind.impl.BinderImpl.doPropertyChange(BinderImpl.java:435)
at org.zkoss.bind.impl.BinderImpl.access$300(BinderImpl.java:132)
at org.zkoss.bind.impl.BinderImpl$QueueListener.onEvent(BinderImpl.java:394)
at org.zkoss.zk.ui.event.impl.DesktopEventQueue$QueueListener.onEvent(DesktopEventQueue.java:168)
at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:3168)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3138)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3080)
at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1846)
at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1618)
at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1321)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:611)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:487)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:495)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:151)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:198)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:176)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:57)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:110)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)

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Hibernate Domain Model:

@Temporal(TemporalType.TIMESTAMP)
@Column(name = "startDate", length = 19, nullable = false)
public Date getStartDate()

{ return this.startDate; }

public void setStartDate(Date startDt)

{ this.startDate= startDate; }

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