Tomcat提供了org.springframework.beans.factory.CannotLoadBeanClassException：

Question

I am working with the following setup

WEB-INF/classes/com/myorg/springmvctutorial/web/controller/HelloWorldController.java

  package com.myorg.springmvctutorial.web.controller;
  import org.springframework.web.servlet.mvc.Controller;
  import org.springframework.web.servlet.ModelAndView;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import java.io.IOException;

  public class HelloWorldController implements Controller {
    protected final Log logger = LogFactory.getLog(getClass());
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse       response)
      throws ServletException, IOException {
      logger.info("Return View");
      return new ModelAndView("helloworld.jsp");
    }
  }

WEB-INF/web.xml

  <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                  http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0" metadata-complete="true">

<servlet>
        <servlet-name>SpringMVCTutorial</servlet-name>
        <servlet-class>
          org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
        <servlet-name>SpringMVCTutorial</servlet-name>
        <url-pattern>*.htm</url-pattern>
  </servlet-mapping>
</web-app>

WEB-INF/SpringMVCTutorial-servlet.xml

  <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                  http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0" metadata-complete="true">

<servlet>
        <servlet-name>SpringMVCTutorial</servlet-name>
        <servlet-class>
          org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
        <servlet-name>SpringMVCTutorial</servlet-name>
        <url-pattern>*.htm</url-pattern>
  </servlet-mapping>
</web-app>

However, when I start my tomcat , it cannot find the class definition of HelloWorldController. Can someone spot the mistake? This is the exception I get

  Jun 09, 2014 12:04:57 AM org.apache.catalina.core.ApplicationContext log
  INFO: Initializing Spring FrameworkServlet 'SpringMVCTutorial'
  Jun 09, 2014 12:04:57 AM org.apache.catalina.core.ApplicationContext log
  SEVERE: StandardWrapper.Throwable
  org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class       [com.myorg.springmvctutorial.web.controller.HelloWorldController] for bean with name '/helloworld.htm' defined in ServletContext resource [/WEB-INF/SpringMVCTutorial-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.myorg.springmvctutorial.web.controller.HelloWorldController
    at       org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1327)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:594)
at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1396)
at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:959)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:683)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:658)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:624)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:672)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:543)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:484)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:160)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1267)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1186)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1081)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1114)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1673)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
  Caused by: java.lang.ClassNotFoundException: com.myorg.springmvctutorial.web.controller.HelloWorldController
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
at org.springframework.util.ClassUtils.forName(ClassUtils.java:247)
at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1348)
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1319)
... 29 more

  Jun 09, 2014 12:04:57 AM org.apache.catalina.core.StandardContext loadOnStartup
  SEVERE: Servlet /SpringMVC threw load() exception
  java.lang.ClassNotFoundException:       com.myorg.springmvctutorial.web.controller.HelloWorldController
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)

I have spent a lot of time debugging this. Please help!

Answer 1

The Bean class name it is trying to load is

    com.myorg.springmvctutorial.web.controller.HelloWorldController

Which matches the fully qualified name of your controller class:

    com.myorg.springmvctutorial.web.controller.HelloWorldController

Yet the JVM cannot load it. That most likely means that the ".class" file is not in the correct place in the webapp for the classloader to find. And then I see this:

    WEB-INF/classes/com/myorg/springmvctutorial/web/controller/HelloWorldController.java

That's a ".java" file not a ".class" file. (What?!?)

So I suspect that the problem is that you've put the source code instead of the compiled code into your webapp. A mistake like that would certainly explain the symptoms ...