ajax的dwr中一个错误

在使用dwr（struts2.1.6）的时侯，例如做表单或者验证，有时会出现以下的错误：

FreeMarker template error!

Expression parameters.parseContent is undefined on line 45, column 28 in template/ajax/head.ftl.
The problematic instruction:
----------
==> ${parameters.parseContent?string} [on line 45, column 26 in template/ajax/head.ftl]
----------

 

所有的错误基本如下：

FreeMarker template error!

Expression parameters.parseContent is undefined on line 45, column 28 in template/ajax/head.ftl.
The problematic instruction:
----------
==> ${parameters.parseContent?string} [on line 45, column 26 in template/ajax/head.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression parameters.parseContent is undefined on line 45, column 28 in template/ajax/head.ftl.
at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:124)
at freemarker.core.TemplateObject.invalidTypeException(TemplateObject.java:134)
at freemarker.core.BuiltIn$stringBI._getAsTemplateModel(BuiltIn.java:358)
at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
at freemarker.core.Environment.visit(Environment.java:208)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:208)
at freemarker.core.Environment.process(Environment.java:188)
at freemarker.template.Template.process(Template.java:237)
at org.apache.struts2.components.template.FreemarkerTemplateEngine.renderTemplate(FreemarkerTemplateEngine.java:185)
at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:558)
at org.apache.struts2.components.UIBean.end(UIBean.java:512)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
at org.apache.jsp.web.bbs.quiz_002dajax_jsp._jspx_meth_s_005fhead_005f0(quiz_002dajax_jsp.java:111)
at org.apache.jsp.web.bbs.quiz_002dajax_jsp._jspService(quiz_002dajax_jsp.java:74)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:461)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:97)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at share.filter.EncodingFilter.doFilter(EncodingFilter.java:31)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:406)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.cndoctors.servlet.HibernateFilter.doFilter(HibernateFilter.java:38)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:595)

 

解决办法：

1：要在工程中加个struts2-dojo-plugin.jar
2：到JSP页面加上

<%@ taglib prefix="sx" uri="/struts-dojo-tags"%>

3:把<s:head theme="ajax"/>改为<sx:head/>