问题
I have the following problem. I used jdk1.6.0_23 to compile my project with eclipse. but in the server enviroment, tomcat is running with jre1.6.0_31.
What might the cause of SEVERE: Null component Catalina:type=JspMonitor,name=jsp,WebModule=//localhost/myproject,J2EEApplication=none,J2EEServer=none
May 18, 2012 3:40:41 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /usr/java/jre1.6.0_31/lib/amd64/server:/usr/java/jre1.6.0_31/lib/amd64:/usr/java/jre1.6.0_31/../lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
May 18, 2012 3:40:41 PM org.apache.coyote.http11.Http11BaseProtocol init
INFO: Initializing Coyote HTTP/1.1 on http-8084
May 18, 2012 3:40:41 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 436 ms
May 18, 2012 3:40:41 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
May 18, 2012 3:40:41 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/5.5.27
May 18, 2012 3:40:41 PM org.apache.catalina.core.StandardHost start
INFO: XML validation disabled
May 18, 2012 3:40:41 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/home/vas/servers/twit_tomcat/webapps/snp/WEB-INF/lib/jetty-jsp-api-2.1.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/jsp/JspPage.class
May 18, 2012 3:40:41 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/home/vas/servers/twit_tomcat/webapps/snp/WEB-INF/lib/jsp-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/jsp/JspPage.class
May 18, 2012 3:40:41 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/home/vas/servers/twit_tomcat/webapps/snp/WEB-INF/lib/servlet-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
May 18, 2012 3:40:41 PM org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/home/vas/servers/twit_tomcat/webapps/snp/WEB-INF/lib/servlet.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class
May 18, 2012 3:40:43 PM org.apache.commons.modeler.Registry registerComponent
SEVERE: Null component Catalina:type=JspMonitor,name=jsp,WebModule=//localhost/myproject,J2EEApplication=none,J2EEServer=none
May 18, 2012 3:40:43 PM org.apache.coyote.http11.Http11BaseProtocol start
INFO: Starting Coyote HTTP/1.1 on http-8084
May 18, 2012 3:40:43 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8012
May 18, 2012 3:40:43 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/18 config=null
May 18, 2012 3:40:43 PM org.apache.catalina.storeconfig.StoreLoader load
INFO: Find registry server-registry.xml at classpath resource
May 18, 2012 3:40:43 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2116 ms
回答1:
That might be a problem of conflicting jar file. when I deleted jetty jars and two servlet jars from the WEBINF/lib folder, it is ok.
回答2:
update server jre environment of tomcat instance
回答3:
I got this when my project was using JRE 8 instead of JDK 8.
来源：https://stackoverflow.com/questions/10648758/severe-null-component-catalinatype-jspmonitor-name-jsp-webmodule-localhost-m