Error message:
0

Jul14,20153:47:56PMorg.apache.coyote.AbstractProtocolinit
INFO:InitializingProtocolHandler["http-bio-8080"]
Jul14,20153:47:56PMorg.apache.coyote.AbstractProtocolinit
INFO:InitializingProtocolHandler["ajp-bio-8009"]
Jul14,20153:47:56PMorg.apache.catalina.startup.Catalinaload
INFO:Initializationprocessedin684ms
Jul14,20153:47:56PMorg.apache.catalina.core.StandardServicestartInternal
INFO:StartingserviceCatalina
Jul14,20153:47:56PMorg.apache.catalina.core.StandardEnginestartInternal
INFO:StartingServletEngine:ApacheTomcat/7.0.59
Jul14,20153:47:56PMorg.apache.catalina.startup.HostConfigdeployWAR
INFO:Deployingwebapplicationarchive/data/tomcat/webapps/app.war
Jul14,20153:47:56PMorg.apache.catalina.loader.WebappClassLoadervalidateJarFile
INFO:validateJarFile(/data/tomcat/webapps/app/WEB-INF/lib/javax.servlet-api-3.1.0.jar)-jarnotloaded.SeeServletSpec3.0,section10.7.2.Offendingclass:javax/servlet/Servlet.class
SLF4J:Failedtoloadclass"org.slf4j.impl.StaticLoggerBinder".
SLF4J:Defaultingtono-operation(NOP)loggerimplementation
SLF4J:Seehttp://www.slf4j.org/codes.html#StaticLoggerBinderforfurtherdetails.
Jul14,20153:48:08PMorg.apache.catalina.core.StandardContextstartInternal
SEVERE:ErrorlistenerStart
Jul14,20153:48:08PMorg.apache.catalina.core.StandardContextstartInternal
SEVERE:Context[/app]startupfailedduetopreviouserrors
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[Timer-0]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[DubboRegistryFailedRetryTimer-thread-1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[ZkClient-EventThread-16-192.168.1.20:2181]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[localhost-startStop-1-SendThread(192.168.1.20:2181)]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[localhost-startStop-1-EventThread]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[DubboSaveRegistryCache-thread-1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[DubboClientReconnectTimer-thread-1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[NewI/Oclientboss#1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[NewI/Oclientworker#1-1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[dubbo-remoting-client-heartbeat-thread-1]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[DubboClientReconnectTimer-thread-2]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[NewI/Oclientworker#1-2]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads
SEVERE:Thewebapplication[/app]appearstohavestartedathreadnamed[dubbo-remoting-client-heartbeat-thread-2]buthasfailedtostopit.Thisisverylikelytocreateamemoryleak.
Jul14,20153:48:08PMorg.apache.catalina.loader.WebappClassLoaderclearReferencesThreads

The error reported by Tomcat is too vague. No error was reported, only error listener start was prompted. For debugging, we need to get more detailed logs. You can create a new file called logging. Properties in the WEB-INF/classes directory. The content is as follows

handlers=org.apache.juli.FileHandler,java.util.logging.ConsoleHandler

############################################################
#Handlerspecificproperties.
#DescribesspecificconfigurationinfoforHandlers.
############################################################

org.apache.juli.FileHandler.level=FINE
org.apache.juli.FileHandler.directory=${catalina.base}/logs
org.apache.juli.FileHandler.prefix=error-debug.

java.util.logging.ConsoleHandler.level=FINE
java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter

In this way, when we start Tomcat again, we will generate a more detailed log error-debug.2012-05-31.log in the logs directory

let’s go in and see what’s wrong
the mistake I encountered is FileNotFoundException. There should be all kinds of mistakes, so we need to analyze the specific problems