[WICKET-1988] DatePicker is not thread-safe

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.3.5
• Fix Version/s: 1.4-RC2
• Component/s: wicket-datetime
• Assignee: Juegen Donnerstag
• Reporter: Roberto Fasciolo
• Created: 19/Dec/08 17:02
• Updated: 22/Dec/08 21:10
• Resolved: 19/Dec/08 18:14

Description

DatePicker uses 2 SimpleDateFormats as static final fields. That causes random failures under load because SimpleDateFormat is not thread-safe. From its javadocs: "Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally."

For example:
18:34:06,214 (TP-Processor3) ERROR [org.apache.wicket.RequestCycle] - Exception in rendering component: [MarkupContainer [Component id = _header_0]]
org.apache.wicket.WicketRuntimeException: Exception in rendering component: [MarkupContainer [Component id = _header_0]]
at org.apache.wicket.Component.renderComponent(Component.java:2519)
at org.apache.wicket.MarkupContainer.onRender(MarkupContainer.java:1411)
at org.apache.wicket.Component.render(Component.java:2317)
at org.apache.wicket.MarkupContainer.autoAdd(MarkupContainer.java:223)
at org.apache.wicket.markup.resolver.HtmlHeaderResolver.resolve(HtmlHeaderResolver.java:78)
at org.apache.wicket.MarkupContainer.renderNext(MarkupContainer.java:1324)
at org.apache.wicket.MarkupContainer.renderAll(MarkupContainer.java:1427)
at org.apache.wicket.Page.onRender(Page.java:1470)
at org.apache.wicket.Component.render(Component.java:2317)
at org.apache.wicket.Page.renderPage(Page.java:904)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.respond(BookmarkablePageRequestTarget.java:231)
at org.apache.wicket.request.AbstractRequestCycleProcessor.respond(AbstractRequestCycleProcessor.java:104)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1181)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:355)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:200)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.huitale.marketplace.security.SessionHijackingFilter.doFilter(SessionHijackingFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:767)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:697)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:889)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 14
at sun.util.calendar.BaseCalendar.getCalendarDateFromFixedDate(BaseCalendar.java:436)
at java.util.GregorianCalendar.computeFields(GregorianCalendar.java:2081)
at java.util.GregorianCalendar.computeFields(GregorianCalendar.java:1996)
at java.util.Calendar.setTimeInMillis(Calendar.java:1104)
at java.util.Calendar.setTime(Calendar.java:1070)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:859)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:852)
at java.text.DateFormat.format(DateFormat.java:316)
at org.apache.wicket.extensions.yui.calendar.DatePicker.configure(DatePicker.java:390)
at org.apache.wicket.extensions.yui.calendar.DateTimeField$1.configure(DateTimeField.java:128)
at org.apache.wicket.extensions.yui.calendar.DatePicker.renderHead(DatePicker.java:224)
at org.apache.wicket.Component.renderHead(Component.java:2568)
at org.apache.wicket.markup.html.internal.HtmlHeaderContainer$1.component(HtmlHeaderContainer.java:220)
at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:829)
at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:844)
at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:844)
at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:869)
at org.apache.wicket.markup.html.internal.HtmlHeaderContainer.renderHeaderSections(HtmlHeaderContainer.java:211)
at org.apache.wicket.markup.html.internal.HtmlHeaderContainer.onComponentTagBody(HtmlHeaderContainer.java:136)
at org.apache.wicket.Component.renderComponent(Component.java:2480)
... 35 more

happens because one internal SimpleDateFormat's field changes while the class is formatting a date.