WebSphere logs show an exception when trying to use jcl-over-slf4j and axis 1.4 (axis 1 version 1.4). We have already checked that there is no commons-logging.jar present on any application classloader. Due to the hierarchical nature of WebSphere classloader schema, we suspect that Axis/commons-discovery keep seeing some classes from the commons-logging.jar present in the server classloader. Such commos-logging.jar can not be removed from the server (parent) classloader, as it is part of the WebSphere infraestructure.
The exception is:
[30/03/15 13:17:52:305 CEST] 00000044 webapp E com.ibm.ws.webcontainer.webapp.WebApp commonInitializationFinally SRVE0266E: Se ha producido un error al inicializar los servlets:

java.lang.Exception: java.lang.ExceptionInInitializerError
at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:1578)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadOnStartupCheck(ServletWrapper.java:1354)
at com.ibm.ws.webcontainer.webapp.WebApp.doLoadOnStartupActions(WebApp.java:615)
at com.ibm.ws.webcontainer.webapp.WebApp.commonInitializationFinally(WebApp.java:584)
at com.ibm.ws.webcontainer.webapp.WebAppImpl.initialize(WebAppImpl.java:421)
at com.ibm.ws.webcontainer.webapp.WebGroupImpl.addWebApplication(WebGroupImpl.java:88)
at com.ibm.ws.webcontainer.VirtualHostImpl.addWebApplication(VirtualHostImpl.java:169)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApp(WSWebContainer.java:749)
at com.ibm.ws.webcontainer.WSWebContainer.addWebApplication(WSWebContainer.java:634)
at com.ibm.ws.webcontainer.component.WebContainerImpl.install(WebContainerImpl.java:422)
at com.ibm.ws.webcontainer.component.WebContainerImpl.start(WebContainerImpl.java:714)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:1164)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.fireDeployedObjectStart(DeployedApplicationImpl.java:1369)
at com.ibm.ws.runtime.component.DeployedModuleImpl.start(DeployedModuleImpl.java:639)
at com.ibm.ws.runtime.component.DeployedApplicationImpl.start(DeployedApplicationImpl.java:967)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:770)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplicationDynamically(ApplicationMgrImpl.java:1361)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.start(ApplicationMgrImpl.java:2162)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:446)
at com.ibm.ws.runtime.component.CompositionUnitImpl.start(CompositionUnitImpl.java:123)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.start(CompositionUnitMgrImpl.java:389)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.access$500(CompositionUnitMgrImpl.java:117)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl$1.run(CompositionUnitMgrImpl.java:664)
at com.ibm.ws.security.auth.ContextManagerImpl.runAs(ContextManagerImpl.java:5468)
at com.ibm.ws.security.auth.ContextManagerImpl.runAsSystem(ContextManagerImpl.java:5594)
at com.ibm.ws.security.core.SecurityContext.runAsSystem(SecurityContext.java:255)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.startCompositionUnit(CompositionUnitMgrImpl.java:678)
at com.ibm.ws.runtime.component.CompositionUnitMgrImpl.startCompositionUnit(CompositionUnitMgrImpl.java:622)
at com.ibm.ws.runtime.component.ApplicationMgrImpl.startApplication(ApplicationMgrImpl.java:1251)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:57)
at sun.reflect.GeneratedMethodAccessor58.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:260)
at javax.management.modelmbean.RequiredModelMBean$4.run(RequiredModelMBean.java:1141)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:86)
at javax.management.modelmbean.RequiredModelMBean.invokeMethod(RequiredModelMBean.java:1135)
at javax.management.modelmbean.RequiredModelMBean.invoke(RequiredModelMBean.java:988)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:835)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:771)
at com.ibm.ws.management.AdminServiceImpl$1.run(AdminServiceImpl.java:1335)
at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
at com.ibm.ws.management.AdminServiceImpl.invoke(AdminServiceImpl.java:1228)
at com.ibm.ws.management.connector.AdminServiceDelegator.invoke(AdminServiceDelegator.java:181)
at com.ibm.ws.management.connector.ipc.CallRouter.route(CallRouter.java:247)
at com.ibm.ws.management.connector.ipc.IPCConnectorInboundLink.doWork(IPCConnectorInboundLink.java:360)
at com.ibm.ws.management.connector.ipc.IPCConnectorInboundLink$IPCConnectorReadCallback.complete(IPCConnectorInboundLink.java:602)
at com.ibm.ws.ssl.channel.impl.SSLReadServiceContext$SSLReadCompletedCallback.complete(SSLReadServiceContext.java:1819)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.requestComplete(WorkQueueManager.java:558)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.attemptIO(WorkQueueManager.java:608)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.workerRun(WorkQueueManager.java:985)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager$Worker.run(WorkQueueManager.java:1074)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1702)
Caused by: java.lang.ExceptionInInitializerError
at org.apache.axis.transport.http.AxisServlet.<clinit>(AxisServlet.java:73)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:171)
at org.apache.axis.transport.http.AxisServletBase.class$(AxisServletBase.java:58)
at org.apache.axis.transport.http.AxisServletBase.<clinit>(AxisServletBase.java:57)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:357)
at java.lang.Class.newInstance(Class.java:310)
at java.beans.Beans.instantiate(Beans.java:209)
at java.beans.Beans.instantiate(Beans.java:49)
at com.ibm.ws.webcontainer.servlet.ServletWrapper$1.run(ServletWrapper.java:1486)
at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:1475)
... 57 more
Caused by: org.apache.commons.discovery.DiscoveryException: Class org.apache.commons.logging.impl.LogFactoryImpl does not implement org.apache.commons.logging.LogFactory
at org.apache.commons.discovery.tools.ClassUtils.verifyAncestory(ClassUtils.java:135)
at org.apache.commons.discovery.tools.SPInterface.verifyAncestory(SPInterface.java:156)
at org.apache.commons.discovery.tools.SPInterface.newInstance(SPInterface.java:150)
at org.apache.commons.discovery.tools.DiscoverClass.newInstance(DiscoverClass.java:534)
at org.apache.commons.discovery.tools.DiscoverSingleton.find(DiscoverSingleton.java:373)
at org.apache.commons.discovery.tools.DiscoverSingleton.find(DiscoverSingleton.java:333)
at org.apache.axis.components.logger.LogFactory$1.run(LogFactory.java:45)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.axis.components.logger.LogFactory.getLogFactory(LogFactory.java:41)
at org.apache.axis.components.logger.LogFactory.<clinit>(LogFactory.java:33)
... 73 more