OGNL的用法举例。转自ITEYE

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="com.rao.struts2.bean.Sex"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
"-//W3C//DTD HTML 4.01 Transitional//EN">


        My JSP </span><span class="string"><span style="color:#0000ff;">'OGNL1.jsp'</span></span><span> starting page

        "pragma" content="no-cache">
        "cache-control" content="no-cache">
        "expires" content="0">
        "keywords" content="keyword1,keyword2,keyword3">
        "description" content="This is my page">





        <%
            request.setAttribute("req", "request scope");
            request.getSession().setAttribute("sess", "session scope");
            request.getSession().getServletContext().setAttribute("app",
                    "aplication scope");
        %>
    1.通过ognl表达式获取 属性范围中的值

        "#request.req" />

        "#session.sess" />

        "#application.app" />


    2.通过"BACKGROUND-COLOR: #fafafa">ognl表达式创建list 集合 ，并且遍历出集合中的值

        "list" value="{'eeeee','ddddd','ccccc','bbbbb','aaaaa'}">
        "#list" var="o">






    3.通过ognl表达式创建Map 集合 ，并且遍历出集合中的值

        "map"
            value="#{'1':'eeeee','2':'ddddd','3':'ccccc','4':'bbbbb','5':'aaaaa'}">
        "#map" var="o">


            "key" />->"value" />




    4.通过ognl表达式 进行逻辑判断

        if test="'aa' in {'aaa','bbb'}">
            aa 在 集合{'aaa','bbb'}中；
        if>
        else>
            aa 不在 集合{'aaa','bbb'}中；
        else>



        if test="#request.req not in #list">
            不 在 集合list中；
        if>
        else>
            在 集合list中；
        else>


    5.通过ognl表达式 的投影功能进行数据筛选

        "list1" value="{1,2,3,4,5}">
        "#list1.{?#this>2}" var="o">

            ${o }



    5.通过ognl表达式 访问某个类的静态方法和值

        "@java.lang.Math@floor(32.56)" />

        "@com.rao.struts2.action.OGNL1Action@aa" />



    6.ognl表达式 迭代标签 详细

        "list2"
            value="{'aa','bb','cc','dd','ee','ff','gg','hh','ii','jj'}">
        "1">


                    索引


                    值


                    奇？


                    偶？


                    首？


                    尾？


                    当前迭代数量


            "#list2" var="o" status="s">
                "#s.even">pink">

                        "#s.getIndex()" />





                        if test="#s.odd">Yif>
                        else>Nelse>


                        if test="#s.even">Yif>
                        else>Nelse>


                        if test="#s.first">Yif>
                        else>Nelse>


                        if test="#s.isLast()">Yif>
                        else>Nelse>


                    "#s.getCount()"/>







    7.ognl表达式:  if/else if/else 详细
        <% request.setAttribute("aa",0); %>
        if test="#request.aa>=0 && #request.aa<=4">
            在0-4之间；
        if>
        "#request.aa>=4 && #request.aa<=8">
            在4-8之间；

        else>
            大于8；
        else>


    8.ognl表达式: url 详细
        <% request.setAttribute("aa","sss"); %>
        "testAction" namespace="/aa/bb">
            "aa" value="#request.aa">
            "id">100


        "myurl" value="'http://www.baidu.com'">
        value以字符处理：   "#myurl">
        value明确指定以ognl表达式处理:    "%{#myurl}">


    9.ognl表达式: checkboxlist 详细
        1> .list 生成；~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        name:checkboxlist的名字
        list:checkboxlist要显示的列表
        value:checkboxlist默认被选中的选项,checked=checked
        "checkbox1" list="{'上网','看书','爬山','游泳','唱歌'}" value="{'上网','看书'}" >

        以上生成代码：
           </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox1"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"上网"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox1-1"</span></span><span> checked=</span><span class="string"><span style="color:#0000ff;">"checked"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox1-1"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>上网</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox1"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"看书"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox1-2"</span></span><span> checked=</span><span class="string"><span style="color:#0000ff;">"checked"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox1-2"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>看书</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox1"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"爬山"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox1-3"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox1-3"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>爬山</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox1"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"游泳"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox1-4"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox1-4"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>游泳</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox1"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"唱歌"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox1-5"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox1-5"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>唱歌</label>"   </span></li> 
   <li><span>
        2> .Map 生成；~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        name:checkboxlist的名字
        list:checkboxlist要显示的列表
        listKey:checkbox 的value的值
        listValue:checkbox 的lablel(显示的值)
        value:checkboxlist默认被选中的选项,checked=checked
        "checkbox2" list="#{1:'上网',2:'看书',3:'爬山',4:'游泳',5:'唱歌'}" listKey="key" listValue="value" value="{1,2,5}" >

        以上生成代码：
           </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox2"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"1"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox2-1"</span></span><span> checked=</span><span class="string"><span style="color:#0000ff;">"checked"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox2-1"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>上网</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox2"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"2"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox2-2"</span></span><span> checked=</span><span class="string"><span style="color:#0000ff;">"checked"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox2-2"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>看书</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox2"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"3"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox2-3"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox2-3"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>爬山</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox2"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"4"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox2-4"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox2-4"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>游泳</label>   </span></li> 
   <li><span>            <input type=</span><span class="string"><span style="color:#0000ff;">"checkbox"</span></span><span> name=</span><span class="string"><span style="color:#0000ff;">"checkbox2"</span></span><span> value=</span><span class="string"><span style="color:#0000ff;">"5"</span></span><span> id=</span><span class="string"><span style="color:#0000ff;">"checkbox2-5"</span></span><span> checked=</span><span class="string"><span style="color:#0000ff;">"checked"</span></span><span>/>   </span></li> 
   <li><span>            <label </span><span class="keyword"><strong><span style="color:#7f0055;">for</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkbox2-5"</span></span><span> </span><span class="keyword"><strong><span style="color:#7f0055;">class</span></strong></span><span>=</span><span class="string"><span style="color:#0000ff;">"checkboxLabel"</span></span><span>>唱歌</label>   </span></li> 
   <li><span>

    10.ognl表达式: s:radio 详细
        <%
            Sex sex1 = new Sex(1,"男");
            Sex sex2 = new Sex(2,"女");
            List list = new ArrayList();
            list.add(sex1);
            list.add(sex2);
            request.setAttribute("sexs",list);
        %>
        这个与checkboxlist差不多；
        1>.如果集合为javabean："sex" list="#request.sexs" listKey="id" listValue="name">
        2>.如果集合为list："sexList" list="{'男','女'}">
        3>.如果集合为map："sexMap" list="#{1:'男',2:'女'}" listKey="key" listValue="value">

    11.ognl表达式: s:select 详细
        这个与s:checkboxlist差不多；
        1>.如果集合为javabean："sex" list="#request.sexs" listKey="id" listValue="name">
        2>.如果集合为list："sexList" list="{'男','女'}">
        3>.如果集合为map："sexMap" list="#{1:'男',2:'女'}" listKey="key" listValue="value">
    到此主要的ognl标签已经介绍完毕...由于表单标签相对简单不介绍了....

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="com.rao.struts2.bean.Sex"%>
<%@ taglib prefix="s" uri="/struts-tags"%>


	
		

		
		
		
		
		
		

	

	
		<%
			request.setAttribute("req", "request scope");
			request.getSession().setAttribute("sess", "session scope");
			request.getSession().getServletContext().setAttribute("app",
					"aplication scope");
		%>
	1.通过ognl表达式获取 属性范围中的值
		

		
		

		
		

		
		

		

	2.通过ognl表达式创建list 集合 ，并且遍历出集合中的值
		

		
		
			
			
			

		
		

		

	3.通过ognl表达式创建Map 集合 ，并且遍历出集合中的值
		

		
		
			
			
			->
			

		
		

		

	4.通过ognl表达式 进行逻辑判断
		

		
			aa 在 集合{'aaa','bbb'}中；
		
		
			aa 不在 集合{'aaa','bbb'}中；
		

		


		
			不 在 集合list中；
		
		
			在 集合list中；
		
		

		

	5.通过ognl表达式 的投影功能进行数据筛选
		

		
		
			
			${o }

		
		

		

	5.通过ognl表达式 访问某个类的静态方法和值
		

		

		
		

		

		

	6.ognl表达式 迭代标签 详细
		

		
		
				pink">
					

			

				

					索引
				
				

					值
				
				

					奇？
				
				

					偶？
				
				

					首？
				
				

					尾？
				
				

					当前迭代数量
				
			
			

						
					
					

						
					
					

						Y
						N
					
					

						Y
						N
					
					

						Y
						N
					
					

						Y
						N
					
					

					
				
				

			
		
		

		

	7.ognl表达式:  if/else if/else 详细

		<% request.setAttribute("aa",0); %>
		
			在0-4之间；
		
		
			在4-8之间；
		
		
			大于8；
		
		

		

	8.ognl表达式: url 详细

		<% request.setAttribute("aa","sss"); %>
		
			
			100
		
		

		
		value以字符处理：   

		value明确指定以ognl表达式处理:    
		

		

	9.ognl表达式: checkboxlist 详细

		1> .list 生成；~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		name:checkboxlist的名字

		list:checkboxlist要显示的列表

		value:checkboxlist默认被选中的选项,checked=checked

		
		

		以上生成代码：

		
			<input type="checkbox" name="checkbox1" value="上网" id="checkbox1-1" checked="checked"/>
			<label for="checkbox1-1" class="checkboxLabel">上网</label>
			<input type="checkbox" name="checkbox1" value="看书" id="checkbox1-2" checked="checked"/>
			<label for="checkbox1-2" class="checkboxLabel">看书</label>
			<input type="checkbox" name="checkbox1" value="爬山" id="checkbox1-3"/>
			<label for="checkbox1-3" class="checkboxLabel">爬山</label>
			<input type="checkbox" name="checkbox1" value="游泳" id="checkbox1-4"/>
			<label for="checkbox1-4" class="checkboxLabel">游泳</label>
			<input type="checkbox" name="checkbox1" value="唱歌" id="checkbox1-5"/>
			<label for="checkbox1-5" class="checkboxLabel">唱歌</label>"
		
		2> .Map 生成；~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		name:checkboxlist的名字

		list:checkboxlist要显示的列表

		listKey:checkbox 的value的值

		listValue:checkbox 的lablel(显示的值)

		value:checkboxlist默认被选中的选项,checked=checked

		
		

		以上生成代码：

		
			<input type="checkbox" name="checkbox2" value="1" id="checkbox2-1" checked="checked"/>
			<label for="checkbox2-1" class="checkboxLabel">上网</label>
			<input type="checkbox" name="checkbox2" value="2" id="checkbox2-2" checked="checked"/>
			<label for="checkbox2-2" class="checkboxLabel">看书</label>
			<input type="checkbox" name="checkbox2" value="3" id="checkbox2-3"/>
			<label for="checkbox2-3" class="checkboxLabel">爬山</label>
			<input type="checkbox" name="checkbox2" value="4" id="checkbox2-4"/>
			<label for="checkbox2-4" class="checkboxLabel">游泳</label>
			<input type="checkbox" name="checkbox2" value="5" id="checkbox2-5" checked="checked"/>
			<label for="checkbox2-5" class="checkboxLabel">唱歌</label>
		
		

	10.ognl表达式: s:radio 详细

		<%
			Sex sex1 = new Sex(1,"男"); 
			Sex sex2 = new Sex(2,"女");
			List list = new ArrayList(); 
			list.add(sex1);
			list.add(sex2);
			request.setAttribute("sexs",list); 
		%>
		这个与checkboxlist差不多；

		1>.如果集合为javabean：

		2>.如果集合为list：

		3>.如果集合为map：

		

	11.ognl表达式: s:select 详细

		这个与s:checkboxlist差不多；

		1>.如果集合为javabean：

		2>.如果集合为list：

		3>.如果集合为map：

	到此主要的ognl标签已经介绍完毕...由于表单标签相对简单不介绍了....
	

 

附上以上代码运行结果图片：见附件