struts2标签之url标签

下面是struts2标签的常用的用法
<s:url value="/images/copyright.jpg" />
<s:url action="list" namespace="/qxgl" />
一定要注意：url中includeParams的属性的默认值是get，如果没有在struts.xml指定新的值，那么使用url标签引用的所有的静态文件都会带上通过get方法传递的参数值。
另外： includeParams的属性值还有none、all
all,是把get和post中的参数加入到 url参数中 ；
none是不把参数加入到url中；

例如：你在detail.jsp中写入

<link href="<s:url value="/css/styleqxgl.css"/>" rel="stylesheet"
type="text/css">

在浏览器中输入http://localhost/detail.jsp?id=5

<link href="/web应用名称/css/styleqxgl.css?id=5" rel="stylesheet"
type="text/css">
这样浏览器就又下载了一次styleqxgl.css，如果你的系统放在公网上，那么带宽的费用是很贵的，使用浏览器的缓存，可以有效的利用带宽，节约成本。

解决这个问题的办法有两个，一个是<s:url value="/css/styleqxgl.css" includeParams="none"/>

另外一个就是在struts.xml中配置，参考下文：

Setting a default value for includeParams

The property struts.url.includeParams can be used to set the default value of the includeParams attribute.

Setting the default value of includeParams

<struts>
   ...
<constant name="struts.url.includeParams" value="none" />
   ...
</struts>

See Constant Configuration for further information.

Parameters

Name	Required	Default	Evaluated	Type	Description
action	false		false	String	The action to generate the URL for, if not using value
anchor	false		false	String	The anchor for this URL
encode	false	true	false	Boolean	Whether to encode parameters
escapeAmp	false	true	false	Boolean	Specifies whether to escape ampersand (&) to (&amp or not
forceAddSchemeHostAndPort	false	false	false	Boolean	Specifies whether to force the addition of scheme, host and port or not
id	false		false	String	Deprecated. Use 'var' instead
includeContext	false	true	false	Boolean	Whether actual context should be included in URL
includeParams	false	get	false	String	The includeParams attribute may have the value 'none', 'get' or 'all'
method	false		false	String	The method of action to use
namespace	false		false	String	The namespace to use
portletMode	false		false	String	The resulting portlet mode
portletUrlType	false		false	String	Specifies if this should be a portlet render or action URL. Default is "render". To create an action URL, use "action".
scheme	false		false	String	Set scheme attribute
value	false		false	String	The target value to use, if not using action
var	false		false	String	Name used to reference the value pushed into the Value Stack
windowState	false		false	String	The resulting portlet window state