TomcatInstrumentableClassLoader Servlet ClassNotFoundException答案

【问题标题】：TomcatInstrumentableClassLoader Servlet ClassNotFoundExceptionTomcatInstrumentableClassLoader Servlet ClassNotFoundException
【发布时间】：2012-12-31 09:41:58
【问题描述】：

我使用 Tomcat 6 作为我的 Web 应用程序的应用服务器，该应用程序使用 AOP 将 DAO 注入 servlet。

Dec 31, 2012 5:21:01 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files (x86)\Java\jre6\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files (x86)/Java/jre7/bin/client;C:/Program Files (x86)/Java/jre7/bin;C:/Program Files (x86)/Java/jre7/lib/i386;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x86;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x64;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Common Files\Acronis\SnapAPI\;C:\Program Files (x86)\Windows Live\Shared;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\TortoiseSVN\bin;C:\Program Files (x86)\MySQL\MySQL Server 5.5\bin;C:\Program Files (x86)\Java\jdk1.6.0_26\bin;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\eclipse-jee-indigo-SR2-win32\eclipse;;.
Dec 31, 2012 5:21:02 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:BISDAO' did not find a matching property.
Dec 31, 2012 5:21:02 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context/Loader} Setting property 'useSystemClassLoaderAsParent' to 'false' did not find a matching property.
Dec 31, 2012 5:21:02 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Dec 31, 2012 5:21:02 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 288 ms
Dec 31, 2012 5:21:02 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Dec 31, 2012 5:21:02 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.35
Dec 31, 2012 5:21:02 PM org.apache.catalina.core.ApplicationContext log
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 [org.springframework.context.config.internalBeanConfigurerAspect,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,genericDAOImpl,org.springframework.context.weaving.AspectJWeavingEnabler#0,loadTimeWeaver,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,org.springframework.cache.annotation.AnnotationCacheOperationSource#0,org.springframework.cache.interceptor.CacheInterceptor#0,org.springframework.cache.config.internalCacheAdvisor,org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor#0,dataSource,jdbcTemplate,genericDaoImpl,transactionManager,ehcache,cacheManager,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; 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)

下面是我的配置：

我已将 spring-instrument-tomcat-3.1.2.RELEASE.jar 放入 $CATALINA_HOME\lib 并在我的 META-INF 文件夹中包含 context.xml。

<?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">

    <!-- Enable @Required @Autowired @PreDestroy @PostConstruct @Resource -->
    <context:annotation-config />

    <!-- Scan class file in class path for annotated component -> @Component, @Repository, @Service, and @Controller  -->
    <context:component-scan base-package="com.breeze.bis.core.service.jdbcTemplate" />

    <!-- Enable load time weaving for @Configurable -->
    <context:load-time-weaver aspectj-weaving="autodetect" />

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

    <!-- ==================================================================================================== -->

    <!-- Alternate method to enable @Autowired -->
    <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>

    <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;
}

请帮忙。

谢谢。

【问题讨论】：

向我们展示 web.xml，其中可能缺少某些内容、错字或错误的 servlet 声明

标签： spring tomcat servlets aop

【解决方案1】：

您的 servlet 不应在默认包中。把它移到一个合适的包里，它可能会起作用。

【讨论】：

不，GenericServlet 不在默认包中。
该堆栈跟踪确实看起来像是在尝试加载没有包的 GenericServlet，因此您可能会仔细检查您通过名称引用 servlet 的任何地方，它是否正确完成。
我确认 GenericServlet 不在默认包中。
似乎应用程序在加载默认包中的 GenericServlet 时使用默认类加载器，但在运行时加载时使用 TomInstrumentClassLoader。我尝试将 GenericServlet.class 放在默认包中，它通过 TomInstrumentClassLoader 投诉 NoClassDefFoundException。

【解决方案2】：

使用 web.xml 中的自定义包定义 servlet 类

【讨论】：