运行struts2时又出现问题了，本来是用通配符的，却出现了如下错误：

运行struts2时又出现问题了，本来是用通配符的，却出现了如下错误：
Struts Problem Report
Struts has detected an unhandled exception:

Messages: com.bjsxt.struts2.action.TeacherAction
Unable to instantiate Action, com.bjsxt.struts2.action.TeacherAction, defined for 'Teacher_add' in namespace '/actions'com.bjsxt.struts2.action.TeacherAction

File: org/apache/catalina/loader/WebappClassLoader.java
Line number: 1,387

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Stacktraces
Unable to instantiate Action, com.bjsxt.struts2.action.TeacherAction, defined for 'Teacher_add' in namespace '/actions'com.bjsxt.struts2.action.TeacherAction com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:306)
    com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:387)
    com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:186)
    org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
    org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
    com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:458)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:857)
    org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:565)
    org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1509)
    java.lang.Thread.run(Thread.java:619)
java.lang.ClassNotFoundException: com.bjsxt.struts2.action.TeacherAction org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
    com.opensymphony.xwork2.util.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:146)
    com.opensymphony.xwork2.ObjectFactory.getClassInstance(ObjectFactory.java:96)
    com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:149)
    com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:139)
    com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:109)
    com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:287)
    com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:387)
    com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:186)
    org.apache.struts2.impl.StrutsActionProxy.prepare(StrutsActionProxy.java:61)
    org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:39)
    com.opensymphony.xwork2.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:47)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:458)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:857)
    org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:565)
    org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1509)
    java.lang.Thread.run(Thread.java:619)

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You are seeing this page because development mode is enabled. Development mode, or devMode, enables extra debugging behaviors and reports to assist developers. To disable this mode, set:

struts.devMode=false
in your WEB-INF/classes/struts.properties file.
   呵呵，仔细检查后发现：我的struts.xml配置如下：

    <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

    <constant name="struts.devMode" value="true" />
    <package name="actions" namespace="/actions" extends="struts-default">
        <action name="Student*" class="com.bjsxt.struts2.action.StudentAction" method="{1}">
            <result>/Student{1}_success.jsp</result>
        </action>
       
        <action name="*_*" class="com.bjsxt.struts2.action.{1}Action" method="{2}">
            <result>/{1}_{2}success.jsp</result>
        </action>
    </package>

    <!-- Add packages here -->

</struts>

    但是我的jsp的页面的名字确实Teacher_add_success.jsp

     Teacher_delete_success.jsp之类的

    呵呵，错误很明显了：

l.第一个错误：

Unable to instantiate Action, com.bjsxt.struts2.action.TeacherAction, defined for 'Teacher_add' in namespace '/actions'com.bjsxt.struts2.action.TeacherAction

   就是说你的struts.xml中result返回的Action的名字与jsp的名字不一致的原因！！

2.第二个错误：

java.lang.ClassNotFoundException: com.bjsxt.struts2.action.TeacherAction

这是什么意思呢，呵呵仔细看自己的项目，终于发现了，这是报的com.bjsxt.struts2.action.TeacherAction 空指针异常，原来是我的这个类的名字写错了，呵呵，找不到自然的报空指针异常了！！