Eclipse 加载 WebappClassLoader 时出错

Question

当我通过 Eclipse 启动 tomcat 时，我在控制台中收到此异常。我不明白出了什么问题，也找不到任何解决方法。

SEVERE: Error loading WebappClassLoader
  delegate: false
  repositories:
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@63d6a00c
 bm._.ops.web.DataServlet
java.lang.ClassNotFoundException: bm._.ops.web.DataServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1438)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1284)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1068)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:966)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3996)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4266)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:634)
    at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:561)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:496)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1203)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:319)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
    at org.apache.catalina.core.StandardService.start(StandardService.java:448)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)

Mar 26, 2014 10:34:31 AM org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /ops threw load() exception
java.lang.ClassNotFoundException: bm._.ops.web.DataServlet
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1438)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1284)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1068)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:966)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3996)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4266)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:760)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:740)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:544)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:634)
    at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:561)
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:496)
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1203)
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:319)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:120)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1022)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
    at org.apache.catalina.core.StandardService.start(StandardService.java:448)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)

编辑： 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">

    <description>
      OpsTools
    </description>
    <display-name>OpsTools</display-name>
    <servlet>
        <servlet-name>test</servlet-name>
        <servlet-class> bm._.ops.web.Test</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>test</servlet-name>
        <url-pattern>/test</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>upload</servlet-name>
        <servlet-class> bm._.ops.web.FileUploadServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>upload</servlet-name>
        <url-pattern>/upload</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>fileUpload</servlet-name>
        <servlet-class> bm._.ops.web.FileUpload</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>fileUpload</servlet-name>
        <url-pattern>/fileUpload</url-pattern>
    </servlet-mapping>



    <servlet>
        <servlet-name>data</servlet-name>
        <servlet-class> bm._.ops.web.DataServlet</servlet-class>
        <init-param>
            <param-name>propertyFileName</param-name>
            <param-value>vcaps.properties</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>data</servlet-name>
        <url-pattern>/data</url-pattern>
    </servlet-mapping>


</web-app>

Answer 1

验证您的 web.xml。 它说找不到该类，因为该类不存在或 web.xml 不正确。 发布您的 web.xml 文件

Answer 2

导航：：“右键单击（项目名称）--> 属性--> 源”选项卡并确保选择“项目/WebContent/WEB-INF/classes”作为默认输出文件夹。

类文件应该在“project/WebContent/WEB-INF”...