用spring2.5+struts2+ibatis2搭建了一个系统，本来只想做个小测试的。谁知道，一运行就抛错：
2009-5-27 17:09:03 org.apache.catalina.core.StandardContext filterStart 严重: Exception starting filter struts2 Unable to load configuration. - bean - jar:file:/E:/app/eclipse-tomcat-6.0.18/webapps/book/WEB-INF/lib/struts2-core-2.1.6.jar!/struts-default.xml:51:89 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:58) at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360) at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:403) at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:190) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275) at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397) at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108) at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4363) Caused by: Unable to load bean: type: class:org.apache.struts2.views.freemarker.FreemarkerManager - bean - jar:file:/E:/app/eclipse-tomcat-6.0.18/webapps/book/WEB-INF/lib/struts2-core-2.1.6.jar!/struts-default.xml:51:89 at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:222) at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101) at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:165) at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55) ... 30 more Caused by: java.lang.NoClassDefFoundError: freemarker/template/SimpleHash 2009-5-27 17:09:03 org.apache.catalina.core.StandardContext start 严重: Error filterStart怎么会冒出个freemarker啊？真奇怪，我没有用到它啊。
没办法，只好找来freemarker-2.3.13.jar加入之后，没有报错了。^_^
很多人都是因为jar缺少或者多余造成了系统的出错。正常使用struts2.1.6，至少需要如下6 个jar包：
struts2-core-2.1.6.jar freemarker-2.3.13.jar commons-logging-1.0.4.jar ognl-2.6.11.jar xwork-2.1.2.jar commons-fileupload-1.2.1.jar
还有时候会有莫名其妙的报错。有时候重新建立一遍工程就好了。
希望对大家有帮助。
相关资源：敏捷开发V1.0.pptx
