[WICKET-4687] ConcurrentModificationException with IFeedback instances that contain other IFeedback instances

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.0.0-beta3
• Fix Version/s: 1.5.8, 6.0.0
• Component/s: wicket
• Labels: ConcurrentModificationException IFeedback,
• Assignee: Martin Tzvetanov Grigorov
• Reporter: Curtis Crabb
• Created: 31/Jul/12 22:50
• Updated: 02/Aug/12 12:06
• Resolved: 02/Aug/12 12:06

Description

When an implementation of IFeedback contains a component that dynamically constructs a child instance of IFeedback, a ConcurrentModificationException will occur. This is easily replicated through the use of a FormComponentFeedbackBorder which contains a refreshing repeater (ListView) that constructs a FeedbackPanel.

Here is the exception:

java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.next(AbstractList.java:343)
at org.apache.wicket.Component.internalPrepareForRender(Component.java:2212)
at org.apache.wicket.Page.internalPrepareForRender(Page.java:246)
at org.apache.wicket.Component.render(Component.java:2281)
at org.apache.wicket.Page.renderPage(Page.java:1020)
at org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:115)
at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:237)
at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:165)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:814)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:253)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:210)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:281)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:245)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1332)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:477)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:227)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1031)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:406)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:965)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:348)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:452)
at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:884)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:938)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:630)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:230)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:77)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:606)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:46)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
at java.lang.Thread.run(Thread.java:662)