Struts中在前台中通过<s: fielderror />拿到action中addFieldError("fielderror.test", "wrong!")添加的错误信息是，默认情况下是带了<ul><li>...</li></ul>格式的。这个给自己设定错误信息的表现带来不便，三种解决方法：
1. 在前台jsp页面中加入css控制
.formFieldError ul li{
list-style-type: none
}
<div>
<s:fielderror />
</div>
2. 在struts.xml中配置配置如下常量时，默认的ui主题会到struts-core的jar包中找对应的配置
<constant value="simple" />
这个配置截图：
若value=simple，则找template.simple中配置，这里的value还可以取值xhtml,css_xhtml,xhtml，那么对应的就找对应的template中的ui配置，其中有一个文件为/template/simple/fielderror.ftl。只要自己在src下定义一个相同名称的配置，然后删除其中的加格式的部分就可以了。
删除后如下，直接拷贝到fielderror.ftl中
<#--
/*
* $Id: fielderror.ftl 722375 2008-12-02 05:19:57Z wesw $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
*
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
-->
<#if fieldErrors??><#t/>
<#assign eKeys = fieldErrors.keySet()><#t/>
<#assign eKeysSize = eKeys.size()><#t/>
<#assign doneStartUlTag=false><#t/>
<#assign doneEndUlTag=false><#t/>
<#assign haveMatchedErrorField=false><#t/>
<#if (fieldErrorFieldNames?size > 0) ><#t/>
<#list fieldErrorFieldNames as fieldErrorFieldName><#t/>
<#list eKeys as eKey><#t/>
<#if (eKey = fieldErrorFieldName)><#t/>
<#assign haveMatchedErrorField=true><#t/>
<#assign eValue = fieldErrors[fieldErrorFieldName]><#t/>
<#if (haveMatchedErrorField && (!doneStartUlTag))><#t/>
<ul<#rt/>
<#if parameters.cssClass??>
class="${parameters.cssClass?html}"<#rt/>
<#else>
class="errorMessage"<#rt/>
</#if>
<#if parameters.cssStyle??>
style="${parameters.cssStyle?html}"<#rt/>
</#if>
>
<#assign doneStartUlTag=true><#t/>
</#if><#t/>
<#list eValue as eEachValue><#t/>
<li><span>${eEachValue}</span></li>
</#list><#t/>
</#if><#t/>
</#list><#t/>
</#list><#t/>
<#if (haveMatchedErrorField && (!doneEndUlTag))><#t/>
</ul>
<#assign doneEndUlTag=true><#t/>
</#if><#t/>
<#else><#t/>
<#if (eKeysSize > 0)><#t/>
<#list eKeys as eKey><#t/>
<#assign eValue = fieldErrors[eKey]><#t/>
<#list eValue as eEachValue><#t/>
<span>${eEachValue}</span>
</#list><#t/>
</#list><#t/>
</#if><#t/>
</#if><#t/>
</#if><#t/>
3. 直接将struts.xml中的<constant value="simple" />中的value改为自己自定义的值，如
<constant value="mytheme" />
然后在src中定义template.mytheme将原来默认的配置全部拷进去，然后在这里面像2那样改掉fielderror.ftl。