TomcatInstrumentableClassLoader Servlet ClassNotFoundException

[peterwkc]

I using Tomcat 6 as the App Server for my web application which uses the AOP to inject DAO into servlet but the problem 1 is Tomcat still using the default server class loader rather than TomcatInstrumentableClassLoader to load the GenericServlet. From the stacktrace, Error loading org.springframework.instrument.classloading.tomcat .TomcatInstrumentableClassLoader. Why is it ?

Problem 2 is Tomcast class loader tries to load GenericServlet from default package rather than custom defined package. Thus, I tried to put GenericServlet.class into default package and I realized the TomcatInstrumentableClassLoader complaints NoClassDefFoundError.

Question 1:
As mentione as above.

Question 2:
I create this project (DAO) as war dynamic project in eclipse ?
How to use this DAO in another project such as war project using @Autowired GenericDAO ? Is it merge applicationContext.xml or configure contextConfigLocation ? Is it using XMLApplicationContext for jar project ?

StackTrace:

INFO: Initializing Spring root WebApplicationContext
17:21:02,477  INFO ContextLoader:272 - Root WebApplicationContext: initialization started
17:21:02,571  INFO XmlWebApplicationContext:510 - Refreshing Root WebApplicationContext: startup date [Mon Dec 31 17:21:02 SGT 2012]; root of context hierarchy
17:21:02,635  INFO XmlBeanDefinitionReader:315 - Loading XML bean definitions from ServletContext resource [/WEB-INF/applicationContext.xml]
17:21:02,967  INFO DefaultContextLoadTimeWeaver:89 - Using a reflective load-time weaver for class loader: org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader
17:21:03,614  INFO DefaultListableBeanFactory:577 - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@188c838: defining beans root of factory hierarchy
17:21:03,944  INFO EhCacheManagerFactoryBean:100 - Initializing EHCache CacheManager
17:21:04,263  INFO MLog:80 - MLog clients using log4j logging.
17:21:04,330  INFO C3P0Registry:204 - Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
17:21:04,471  INFO ContextLoader:301 - Root WebApplicationContext: initialization completed in 1993 ms
Dec 31, 2012 5:21:04 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
Dec 31, 2012 5:21:04 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Dec 31, 2012 5:21:04 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/11  config=null
Dec 31, 2012 5:21:04 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2354 ms
Dec 31, 2012 5:21:08 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet GenericServlet as unavailable
Dec 31, 2012 5:21:08 PM org.apache.catalina.core.ApplicationContext log
SEVERE: Error loading org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader
WebappClassLoader
  context: /BISDAO
  delegate: false
  repositories:
    /WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@3c0007
 GenericServlet
java.lang.ClassNotFoundException: GenericServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1128)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:827)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Unknown Source)
Dec 31, 2012 5:21:08 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet GenericServlet
java.lang.ClassNotFoundException: GenericServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1128)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:827)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Unknown Source)

Below is my configuration:

I have put spring-instrument-tomcat-3.1.2.RELEASE.jar into $CATALINA_HOME\lib and have context.xml inside my META-INF folder.

<?xml version='1.0' encoding='utf-8'?>
<Context path="/BISDAO">
    <Loader loaderClass="org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader" />
</Context>

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-2.5.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

    <context:annotation-config />

    <context:component-scan base-package="com.breeze.bis.core.service.jdbcTemplate" />

    <context:load-time-weaver aspectj-weaving="autodetect" />

    <tx:annotation-driven proxy-target-class="false" transaction-manager="transactionManager"/>

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/vbossdb" />
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="user" value="root" />
        <property name="password" value="root" />
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <constructor-arg type="javax.sql.DataSource" ref="dataSource"></constructor-arg>
    </bean>

    <bean id="genericDaoImpl" class="com.breeze.bis.core.service.jdbcTemplate.GenericDAOImpl">
        <property name="jdbcDao" ref="jdbcTemplate"></property> 
    </bean>

    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property> 
    </bean>
</beans>

Servlet.java

@Configurable
public class GenericServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Autowired
    GenericDAO dao;
}

Please help.
Thanks.

[Marten Deinum]

I suggest a read of the reference guide.

First it is a bad idea to put classes in the default package simply put it in a package and reference it from the web.xml (as you should have done).

Second your configuration is flawed as there is nothing indicating that you want to use spring to do dependency injection into other objects. You need to add context:spring-configured into your context file else your @Configurable is pretty much useless.).

[peterwkc]

First, I did not put the classes in default package.
Second, I had put context:spring-configured into your context file.

The problem is why error loading TomcatInstrumentableClassLoader.

[peterwkc]

Solved this problem by add servlet class in web.xml. Thread closed