在上一節搭建完整體環境後，接下來進行以下幾個步驟：
1. 修改 "項目 -> src -> struts.xml"：
將以下代碼
<package name="default" namespace="/" extends="struts-default">
<default-action-ref name="index" />
<action name="index">
<result type="redirectAction">
<param name="actionName">HelloWorld</param>
<param name="namespace">/example</param>
</result>
</action>
</package>
改爲：
<package name="default" namespace="/" extends="struts-default">
<action name="hello">
<result>/Hello.jsp</result>
</action>
</package>
2. 運行時出現問題：提示沒有jdk，還一直以爲是沒有添加tomcat，反覆查詢
"myeclipse -> windows -> reference -> ... -> tomcat6.0"，結果發現還可以繼續往下點擊，展開就是 jdk 設置處。
3. 如何使修改 struts.xml 裏的 <action> 後，不用重啓tomcat，就可以自動完成action配置呢？
看視頻時，是修改 struts.xml 裏面的常量 struts.devMode 值爲 true：
<constant name="struts.devMode" value="true" />
但修改完之後，一重啓tomcat就出現錯誤呢！！！這個問題還沒解決好吖！！
嚴重: Exception starting filter struts2
java.lang.NullPointerException
at com.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)
at com.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)
at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)
at org.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)
at com.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:61)
at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:774)
at org.apache.struts2.dispatcher.ng.InitOperations.initStaticContentLoader(InitOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:49)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4072)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4726)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1079)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1002)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:506)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
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(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
2012-9-6 0:04:15 org.apache.catalina.core.StandardContext start
嚴重: Error filterStart
2012-9-6 0:04:15 org.apache.catalina.core.StandardContext start
嚴重: Context [/Struts2_0100_Introduction] startup failed due to previous errors
2012-9-6 0:04:15 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
嚴重: The web application [/Struts2_0100_Introduction] created a ThreadLocal with key of type [com.opensymphony.xwork2.inject.ContainerImpl$10] (value [com.opensymphony.xwork2.inject.ContainerImpl$10@1eee615]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@143a515])
but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
2012-9-6 0:04:15 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
嚴重: The web application [/Struts2_0100_Introduction] created a ThreadLocal with key of type [com.opensymphony.xwork2.inject.ContainerImpl$10] (value [com.opensymphony.xwork2.inject.ContainerImpl$10@b368f]) and a value of type [java.lang.Object[]] (value [[Ljava.lang.Object;@2b105d])
but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
2012-9-6 0:04:16 org.apache.coyote.http11.Http11Protocol start
4. 幾乎一個晚上都糾結在上面第3點。到底要怎麼辦好呢？