Exception triggered an automatic undeploy

[Howard Loo <hl...@gmail.com>]

I have been using an installation of Tomcat 6.0.7 for a few months with no
problems.  However, tonight my webapp threw an exception that somehow
triggered an automatic undeploy of my webapp, blowing it away without
warning.  I have solved the problem with my installation, but I wanted to
report this phenomenon just in case it was caused in part by a bug in
Tomcat.

An excerpt from catalina.out containing the relevant stack trace is below,
but here is what I've been able to ascertain regarding the problem.  My
webapp could not find the JDBC driver class com.mysql.jdbc.Driver, and threw
an exception.  I had the JAR containing this class in my WEB-INF/lib
directory, but not in the lib/ directory that is a sibling of the webapps/
directory.  Once I copied the JAR into the lib/ directory, my webapp worked
fine.  However, before doing that, my webapp would throw an exception and
then automatically undeploy.  (See stack trace below.)

(Note that this same phenomenon of automatically undeploying also occurred
previously in response to a javax.naming.NameNotFoundException exception
being thrown.  I believe this particular exception was caused in part by a
configuration error in my webapp's META-INF/context.xml file.)

Sincerely,
Howard Loo

***
INFO: Server startup in 1420 ms
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot load JDBC driver
class 'com.mysql.jdbc.Driver'
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(
BasicDataSource.java:766)
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(
BasicDataSource.java:540)
        at myapp.MyServlet.doGet(TagServlet.java:18)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(
ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(
StandardWrapperValve.java:228)
        at org.apache.catalina.core.StandardContextValve.invoke(
StandardContextValve.java:175)
        at org.apache.catalina.core.StandardHostValve.invoke(
StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(
ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(
StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(
CoyoteAdapter.java:212)
        at org.apache.coyote.http11.Http11Processor.process(
Http11Processor.java:844)
        at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
Http11Protocol.java:634)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(
JIoEndpoint.java:445)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(
BasicDataSource.java:760)
        ... 16 more
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot load JDBC driver
class 'com.mysql.jdbc.Driver'
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(
BasicDataSource.java:766)
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(
BasicDataSource.java:540)
        at myapp.TagServlet.doGet(TagServlet.java:18)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(
ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(
StandardWrapperValve.java:228)
        at org.apache.catalina.core.StandardContextValve.invoke(
StandardContextValve.java:175)
        at org.apache.catalina.core.StandardHostValve.invoke(
StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(
ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(
StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(
CoyoteAdapter.java:212)
        at org.apache.coyote.http11.Http11Processor.process(
Http11Processor.java:844)
        at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
Http11Protocol.java:634)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(
JIoEndpoint.java:445)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(
BasicDataSource.java:760)
        ... 16 more
Mar 7, 2007 8:25:32 PM org.apache.catalina.startup.HostConfig checkResources
INFO: Undeploying context [/myapp]
***