[MSITE-754] ConcurrentModificationException when using site:run

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4
• Fix Version/s: 3.5
• Component/s: site:run
• Environment: Maven 2.2.1 with maven-site-plugin 3.0
• Assignee: Herve Boutemy
• Reporter: Christof Schöll
• Created: 04/Apr/12 05:35
• Updated: 20/Dec/15 03:22
• Resolved: 20/Dec/15 03:22

Description

When using maven with site:run I get the following exception, which seem to originate from the Doxia Site Renderer

2012-04-04 12:27:07.653:WARN::/css/maven-theme.css
java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
        at java.util.AbstractList$Itr.next(AbstractList.java:343)
        at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.locateDocumentFiles(DefaultSiteRenderer.java:149)
        at org.apache.maven.plugins.site.webapp.DoxiaFilter.doFilter(DoxiaFilter.java:174)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:440)
        at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
        at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:926)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
        at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
2012-04-04 12:27:07.656:WARN::/images/logos/maven-feather.png
java.util.ConcurrentModificationException
        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
        at java.util.AbstractList$Itr.next(AbstractList.java:343)
        at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.locateDocumentFiles(DefaultSiteRenderer.java:149)
        at org.apache.maven.plugins.site.webapp.DoxiaFilter.doFilter(DoxiaFilter.java:174)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:440)
        at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
        at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:926)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
        at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

The following source code in org.apache.maven.doxia.siterenderer.DefaultSiteRenderer (line 149) seems to contain the problem:

149  for ( File siteDirectory : siteRenderingContext.getSiteDirectories() )
150         {
151             if ( siteDirectory.exists() )
152             {
153                 Collection<SiteModule> modules = siteModuleManager.getSiteModules();
154                 for ( SiteModule module : modules )
155                 {
156                     File moduleBasedir = new File( siteDirectory, module.getSourceDirectory() );
157 
158                     if ( moduleExcludes != null && moduleExcludes.containsKey( module.getParserId() ) )
159                     {
160                         addModuleFiles( moduleBasedir, module, moduleExcludes.get( module.getParserId() ),
161                                 files );
162                     }
163                     else
164                     {
165                         addModuleFiles( moduleBasedir, module, null, files );
166                     }
167                 }
168             }
169         }

Iterating over a clone of the siteDirectories should make this code much more robust and should generally fix this problem.