EL&struts2标签 读取map,list集合

    struts中的取map和list & jsp中取map和list
    <%
        List list = new ArrayList();
        list.add("a");
        list.add("b");
        list.add("c");
        request.setAttribute("l1",list);

        Map map = new HashMap()    ;
        map.put("a","a");
 map.put(1L,"b"); //这里的1要强转成long类型，因为el表达式的数字都是long类型
        request.setAttribute("m1",map);

     %>
<!--上面已经压入了了值栈中-->
     <s:debug ></s:debug>
     <br/>
     [原EL表达式取值list,map]
<br/>
     list:
    ${l1[0]}
    ${l1[1]}
    ${l1[2]}
    </br>
    map:
    ${m1["a"]}
    ${m1[1]}
    <br/>
    [struts2中取值]
<br/>
    map两种:
<s:iterator value="#request.m1" id="name">
        <s:property value="key"/>=<s:property value="value"/>

    </s:iterator>
    <br/>
    <s:iterator value="#request.m1" id="name" var="var">
        <s:property value="#var.key"/>=<s:property value="#var.value"/>

    </s:iterator>
    <hr/>
    list:
<s:iterator value="#request.l1" id="name" var="var" status="s">
<!--    iterator是循环迭代，添加一个条件若该元素的索引是1，则打印出这个元素的值-->
        <s:if test="#s.getIndex()==1">
        <s:property value="#var"/>
        </s:if>
    </s:iterator>

页面输出结果

struts中的取map和list & jsp中取map和list

[Debug]

[原EL表达式取值list,map] 
list: a b c 
map: a b 
[struts2中取值] 
map两种: 1=b a=a 
1=b a=a

---

list: b