struts2标签

一、通用标签

1、property

　　

Name	Required	Default	Evaluated	Type	Description
default	false		false	String	The default value to be used if value attribute is null
escape	false	true	false	Boolean	Deprecated. Use 'escapeHtml'. Whether to escape HTML
escapeCsv	false	false	false	Boolean	Whether to escape CSV (useful to escape a value for a column)
escapeHtml	false	true	false	Boolean	Whether to escape HTML
escapeJavaScript	false	false	false	Boolean	Whether to escape Javascript
escapeXml	false	false	false	Boolean	Whether to escape XML
value	false	<top of stack>	false	Object	Value to be displayed

　　<s:property value="username" />输出变量名为username的变量，value中的值会被当成ognl表达式输出

　　<s:property value="'username'" />输出username,加了单引号不会当成ognl表达式而是当成字符串输出

　　<s:property value="admin" default="xiaoming" /> 输出变量名为admin的值,如果没有则默认为xiaoming

　　<s:property value="'<br/>'" escape="false" />

2、set

Name	Required	Default	Evaluated	Type	Description
id	false		false	String	Deprecated. Use 'var' instead
name	false		false	String	Deprecated. Use 'var' instead
scope	false	action	false	String	The scope in which to assign the variable. Can be application, session, request, page, or action.
value	false		false	String	The value that is assigned to the variable named name
var	false		false	String	Name used to reference the value pushed into the Value Stack

　　<s:set var="username" value="xiaomi" />默认为request和ActionContext

　　从request取值<s:property value="#request.username" />（debug标签可能在username还未放到request中时就已经形成了，所以有时候会看不到）

　　从ActionContext取值<s:property value="#username" />

　　

　　设定范围<s:set var="username" value="xiaomi" scope="session" />

　　从设定范围取值<s:property value="#session.username" />

3、bean

Name	Required	Default	Evaluated	Type	Description
id	false		false	String	Deprecated. Use 'var' instead
name	true		false	String	The class name of the bean to be instantiated (must respect JavaBean specification)
var	false		false	String	Name used to reference the value pushed into the Value Stack

　 调用无参构造函数构造一个User类示例：xiaomi<s:bean name="cn.orlion.model.User var="xiaomi"></s:bean>

　　调用无参构造函数构造一个User类示例：dami，初始化name为dami

　　<s:bean name="cn.orlion.model.User var="dami">

　　　　<s:param name="name" value="'dami'"></s:param> 这里value中的值必须要用单引号引起来，不然会被当成ognl表达式！！！

　　</s:bean>

4、include

Name	Required	Default	Evaluated	Type	Description
value	true		false	String	The jsp/servlet output to include

　　<s:include value="/index.jsp" />

　　<s:include value="/index.jsp">

　　　　<s:param name="param1">value1</s:param> （value会被当成字符串处理）

　　　　<s:param name="param2">value2</s:param>

　　</s:include>

　　包含动态文件：

　　<s:set name="url" value="'/index.jsp'" />

　　<s:include value="%{#url}" />

5、param

Name	Required	Default	Evaluated	Type	Description
name	false		false	String	Name of Parameter to set
suppressEmptyParameters	false	false	false	Boolean	Whether to suppress empty parameters
value	false	The value of evaluating provided name against stack	false	String	Value expression for Parameter to set

可以：<s:param name="param1" value="value1" />这里value1会被当成ognl表达式

也可以：<s:param name="param1" />value1</s:param>这里value1会被当成字符串

6、debug

不多作介绍

二、控制标签

1、if elseif else

　　<s:if test="%{false}">

　　　　<p>1</p>

　　</s:if>

　　<s:elseif test="%{true}">

　　　　<p>2</p>

　　</s:elseif>

　　<s:else>

　　　　<p>3</p>

　　</s:else>

2、iterator

Name	Required	Default	Evaluated	Type	Description
begin	false	0	false	Integer	if specified the iteration will start on that index
end	false	Size of the 'values' List or array, or 0 if 'step' is negative	false	Integer	if specified the iteration will end on that index(inclusive)
id	false		false	String	Deprecated. Use 'var' instead
status	false	false	false	Boolean	If specified, an instanceof IteratorStatus will be pushed into stack upon each iteration
step	false	1	false	Integer	if specified the iteration index will be increased by this value on each iteration. It can be a negative value, in which case 'begin' must be greater than 'end'
value	false		false	String	the iteratable source to iterate over, else an the object itself will be put into a newly created List
var	false		false	String	Name used to reference the value pushed into the Value Stack

遍历集合：(输出123)

　　<s:iterator value="{1,2,3}">

　　　　<s:property/>

　　</s:iterator>

自定义变量：（输出ABC）从集合中迭代取出赋值给val

　　<s:iterator value="{'a', 'b' , 'c'}" var="val">

　　　　<s:property value="#val.toUpperCase()"/>

　　</s:iterator>

使用status：

　　<s:iterator value="{'a' , 'b' , 'c'}" status="status">

　　　　<s:property/>

　　　　遍历过的元素的总数<s:property value="#status.count" />

　　　　当前元素的索引<s:property value="#status.index" />

　　　　当前是偶数<s:property value="#status.even" />

　　　　当前是奇数<s:property value="#status.odd" />

　　　　是否是第一个元素<s:property value="#status.first" />

　　　　是否是最后一个元素<s:property value="#status.last" />

　　</s:iterator>

遍历map

　　<s:iterator value="#{1:'a' , 2:'b' , 3:'c'}">

　　　　<s:property value="key" /> | <s:property value="value" />

　　</s:iterator>

　　<s:iterator value="#{1:'a' , 2:'b' , 3:'c'}" var="val">

　　　　<s:property value="#val.key" /> | <s:property value="#val.value" />

　　</s:iterator>

3、subset

Name	Required	Default	Evaluated	Type	Description
count	false		false	Integer	Indicate the number of entries to be in the resulting subset iterator
decider	false		false	org.apache.struts2.util.SubsetIteratorFilter.Decider	Extension to plug-in a decider to determine if that particular entry is to be included in the resulting subset iterator
id	false		false	String	Deprecated. Use 'var' instead
source	false		false	String	Indicate the source of which the resulting subset iterator is to be derived base on
start	false		false	Integer	Indicate the starting index (eg. first entry is 0) of entries in the source to be available as the first entry in the resulting subset iterator
var	false		false	String	The name to store the resultant iterator into page context, if such name is supplied

三、UI标签

1、theme

主题，默认为xhtml,可以设置为simple/css_html/ajax

struts.xml中<constant name="theme" value="simple" />