NullPointerException in WebServerService.getListenerMap ------------------------------------------------------- Key: WFLY-4347 URL: https://issues.jboss.org/browse/WFLY-4347 Project: WildFly Issue Type: Bug Components: Web Services Affects Versions: 8.1.0.Final Environment: Windows, Linux Java 8 Reporter: Mayank Mittal Assignee: Tomaz Cerar While deploying a SLSB annotated with WebService causes NullPointerException in WebServerService.getListenerMap {noformat} org.jboss.msc.service.StartException in service jboss.deployment.subunit."myTest.ear"."myTest.jar".INSTALL: JBAS018733: Failed to process phase INSTALL of subdeployment "myTest.jar" of deployment "myTest.ear" at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:166) at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948) at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.NullPointerException at java.util.LinkedList$ListItr.next(Unknown Source) at org.wildfly.extension.undertow.WebServerService.getListenerMap(WebServerService.java:73) at org.wildfly.extension.undertow.WebServerService.getPort(WebServerService.java:49) at org.jboss.as.webservices.config.WebServerInfoImpl.getPort(WebServerInfoImpl.java:36) at org.jboss.ws.common.management.AbstractServerConfig.getConnectorPort(AbstractServerConfig.java:207) at org.jboss.ws.common.management.AbstractServerConfig.getWebServicePort(AbstractServerConfig.java:170) at org.jboss.ws.common.deployment.EndpointAddressDeploymentAspect$PortValue.getPortValue(EndpointAddressDeploymentAspect.java:198) at org.jboss.ws.common.deployment.EndpointAddressDeploymentAspect$PortValue.getValue(EndpointAddressDeploymentAspect.java:191) at org.jboss.ws.common.deployment.EndpointAddressDeploymentAspect.start(EndpointAddressDeploymentAspect.java:77) at org.jboss.as.webservices.deployers.AspectDeploymentProcessor.deploy(AspectDeploymentProcessor.java:75) at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:159) {noformat} Upon looking into the source code, I found that the the collection used to hold registered listeners in org.wildfly.extension.undertow.Server class is LinkedList. What I understand from the code is that this list is getting accessed by two threads at some moment of time and causes the NullPointerException plz. refer http://stackoverflow.com/questions/18055024/nullpointer-exception-in-link.... I think one should use ConcurrentHashSet to avoid such situations.