ClassNotFoundException when upgraded to Tomcat 8

Question

I recently upgraded my NetBeans IDE from v7.3 to v8 and all of a sudden my application throws an exception at server startup while connecting to DB. The only difference between these two versions of IDE are that the later one is using Tomcat 8.

Exception Log:

javax.naming.NamingException: Could not load resource factory class [Root exception is java.lang.ClassNotFoundException: org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory]
    at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:82)
    at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:841)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:152)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:829)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:152)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:829)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:152)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:829)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:166)
    at org.apache.naming.SelectorContext.lookup(SelectorContext.java:157)
    at javax.naming.InitialContext.lookup(InitialContext.java:411)
    at com.istore.core.listeners.AppContextListener.initdb(AppContextListener.java:44)
    at com.istore.core.listeners.AppContextListener.contextInitialized(AppContextListener.java:27)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4738)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5158)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:697)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:579)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:455)
    at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1554)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1428)
    at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:885)
    at org.apache.catalina.manager.ManagerServlet.doGet(ManagerServlet.java:343)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:301)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:615)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1015)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1575)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1533)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1284)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1132)
    at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:80)
    ... 58 more

META-INF/context.xml

<!-- PostgreSQL Datasource -->
<Resource auth="Container" driverClassName="org.postgresql.Driver" factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory" maxActive="50" maxIdle="10" maxWait="-1" name="jdbc/mydb" type="javax.sql.DataSource" url="jdbc:postgresql://myorg.corp.net:5432/mydb" username="abc" password="def" />

Please guide.

Answer 1

The name of the default factory changed between Tomcat 7 and Tomcat 8. A couple of attribute names also changed. This is all as a result of switching from DBCP 1.x to DBCP 2.x in Tomcat 8. You want the following in your META-INF/context.xml file:

<!-- PostgreSQL Datasource -->
<Resource auth="Container"
          driverClassName="org.postgresql.Driver"
          factory="org.apache.tomcat.dbcp.dbcp2.BasicDataSourceFactory"
          maxTotal="50"
          maxIdle="10"
          maxWaitMillis="-1"
          name="jdbc/mydb"
          type="javax.sql.DataSource"
          url="jdbc:postgresql://myorg.corp.net:5432/mydb"
          username="abc"
          password="def" />

Since this factory is used by default for resources of type javax.sql.DataSource you can just drop that attribute all together. The other changes were:

maxActive -> maxTotal
maxWait   -> maxWaitMillis