java.lang.NoClassDefFoundError：org / hibernate / MappingException

Question

启动我的Apache Tomcat服务器时出现以下错误。 我已经将Struts与Hibernate框架集成在一起。

谁能告诉我这种例外的原因？

启动服务器时会出现PFA异常日志？

Feb 11, 2014 10:46:09 AM 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\Java\jre7\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre7/bin/client;C:/Program Files/Java/jre7/bin;C:/Program Files/Java/jre7/lib/i386;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\eclipse-standard-kepler-R-win32\eclipse;;.
Feb 11, 2014 10:46:09 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:StrutsOne' did not find a matching property.
Feb 11, 2014 10:46:09 AM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Feb 11, 2014 10:46:09 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 766 ms
Feb 11, 2014 10:46:09 AM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Feb 11, 2014 10:46:09 AM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.32
Feb 11, 2014 10:46:10 AM org.apache.struts.action.ActionServlet initChain
INFO: Loading chain catalog from jar:file:/C:/Users/Mohit/workspace/Struts/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/StrutsOne/WEB-INF/lib/struts-core-1.3.10.jar!/org/apache/struts/chain/chain-config.xml
Feb 11, 2014 10:46:10 AM org.apache.struts.action.ActionServlet init
SEVERE: Unable to initialize Struts ActionServlet due to an unexpected exception or error thrown, so marking the servlet as unavailable.  Most likely, this is due to an incorrect or missing library dependency.
java.lang.NoClassDefFoundError: org/hibernate/MappingException
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
    at java.lang.Class.getConstructor0(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at org.apache.struts.util.RequestUtils.applicationInstance(RequestUtils.java:172)
    at org.apache.struts.util.RequestUtils.applicationInstance(RequestUtils.java:147)
    at org.apache.struts.action.ActionServlet.initModulePlugIns(ActionServlet.java:842)
    at org.apache.struts.action.ActionServlet.init(ActionServlet.java:359)
    at javax.servlet.GenericServlet.init(GenericServlet.java:212)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1173)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:993)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4420)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4733)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
    at org.apache.catalina.core.StandardService.start(StandardService.java:525)
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
    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:289)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: java.lang.ClassNotFoundException: org.hibernate.MappingException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
    ... 27 more

Answer 1

如果您在Eclipse中工作，则应在Web项目类路径中添加休眠jar并部署程序集。

通过右键单击项目->属性->部署程序集，然后添加jar。 或（如果jar位于WEB-INF / lib文件夹中），右键单击项目->属性-> Java构建路径->选择“库”选项卡，然后添加库，然后选择weba bb库

Answer 2

您在问这个异常的原因。

请查看日志告诉我们的内容，

“由于意外的异常或引发的错误而无法初始化Struts ActionServlet，因此将Servlet标记为不可用。这很可能是由于不正确或缺少库依赖关系造成的”

启动服务器时，通过拖放war文件或通过eclipse手动部署应用程序的应用程序，应用程序的第一个入口点是部署描述符，即web.xml 。 在这里，您已将Servlet定义为Struts Action Servlet，因此将尝试初始化Struts ActionServlet。

现在，在您的struts-config.xml中，您可能会有类似的内容，

<struts-config>
....
    <plug-in className="com.example.MyHibernatePlugin">
        <set-property property="path" value="/hibernate.cfg.xml"/>
    </plug-in>
....
<struts-config>

com.example MyHibernatePlugin.java

import org.apache.struts.action.PlugIn;
public class HibernatePlugin implements PlugIn { ....{your code} }

话虽如此，现在您的日志正在尝试说些什么，为什么它在尝试初始化Struts Action Servlet时遇到了映射异常。

您的类路径中必须具有与Struts和Hibernate相关的所有库。 不要一次添加全部，一个一个地添加，看看它抱怨哪个罐子，然后添加直到它停止抱怨。