Struts2中iterator标签遍历map总结

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public class MapAction extends ActionSupport
{
private Map<String,String> map;
private Map<String,Student> studentMap;
private Map<String,String[]> arrayMap;
private Map<String,List<Student>> listMap;
public String testMap()
{
map=new HashMap<String,String>();
map.put("1", "one");
studentMap=new HashMap<String,Student>();
studentMap.put("student1",new Student(new Long(1),"20034140201","张三1","男",25));
arrayMap=new HashMap<String,String[]>();
arrayMap.put("arr1", new String[]{"1","2003401","leejie","male","20"});
listMap=new HashMap<String,List<Student>>();
List<Student> list1=new ArrayList<Student>();
list1.add(new Student(new Long(1),"20034140201","张三1","男",25));
list1.add(new Student(new Long(2),"20034140202","张三2","男",25));
list1.add(new Student(new Long(3),"20034140203","张三3","男",25));
listMap.put("class1", list1);
return SUCCESS;
}
public Map<String, String> getMap() {
return map;
}
public void setMap(Map<String, String> map) {
this.map = map;
}
public Map<String, Student> getStudentMap() {
return studentMap;
}
public void setStudentMap(Map<String, Student> studentMap) {
this.studentMap = studentMap;
}
public Map<String, String[]> getArrayMap() {
return arrayMap;
}
public void setArrayMap(Map<String, String[]> arrayMap) {
this.arrayMap = arrayMap;
}
public Map<String, List<Student>> getListMap() {
return listMap;
}
public void setListMap(Map<String, List<Student>> listMap) {
this.listMap = listMap;
}
}

<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<title>struts2中的map遍历总结</title>
</head>
<body>
<b>1.map中的value为String字符串</b><br>
<s:iterator value="map" id="column">
<s:property value="#column"/><br>
key: <s:property value="key"/><br>
value:<s:property value="value"/><br>
</s:iterator>
<b>2.map中的value为Student对象</b>
<table border="1" width="50%" cellspacing="0" cellpadding="0">
<tr>
<td>key=value</td>
<td>ID</td>
<td>sex</td>
<td>age</td>
</tr>
<s:iterator value="studentMap" id="column">
<tr>
<td><s:property value="#column"/></td>
<td><s:property value="value.id"/></td>
<td><s:property value="value.sex"/></td>
<td><s:property value="value.age"/></td>
</tr>
</s:iterator>
</table>
<p>
<b>3.map中的value为String数组</b>
<table border="1" width="50%" cellspacing="0" cellpadding="0">
<tr>
<td>key=value</td>
<td>ID</td>
<td>num</td>
<td>name</td>
<td>sex</td>
<td>age</td>
</tr>
<s:iterator value="arrayMap" id="column">
<tr>
<td><s:property value="#column"/></td>
<td><s:property value="value[0]"/></td>
<td><s:property value="value[1]"/></td>
<td><s:property value="value[2]"/></td>
<td><s:property value="value[3]"/></td>
<td><s:property value="value[4]"/></td>
</tr>
</s:iterator>
</table>
<p>
<b>4.map中的value为list集合</b>
<table border="1" width="50%" cellspacing="0" cellpadding="0">
<tr>
<td>class</td>
<td>ID</td>
<td>num</td>
<td>name</td>
<td>sex</td>
<td>age</td>
</tr>
<s:iterator value="listMap" id="column">
<s:set name="total" value="#column.value.size"/>
<s:iterator value="#column.value" status="s">
<tr>
<s:if test="#s.first"><td rowspan="${total}"><s:property value="#column.key"/></td></s:if>
<td><s:property value="id"/></td>
<td><s:property value="num"/></td>
<td><s:property value="name"/></td>
<td><s:property value="sex"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</s:iterator>
</table>
</body>
</html>

关键字使用： List<String> days ["Monday","Thursday","Friday","Sunday"]

使用top 关键字：使用top 指代当前迭代元素，可以为对象

[html] view plaincopy
<s:iterator value="days">   
<s:if test="top!='Monday'">   
<s:property />   
</s:if>   
</s:iterator>   

使用 last / first 关键字：#of.last用于判断当前迭代到的元素是否为最后一个元素，iterator 标签中的status属性代表当前迭代的位置；

[html] view plaincopy
<s:iterator value="aTs" status="of">    
     <s:if test="#of.last"><br/></s:if>    
     <s:iterator value="top">    
     <span style="white-space:pre"> </span><s:property />    
     </s:iterator>    
 </s:iterator>    

使用 odd / even 关键字：odd关键字用来判断当前迭代位置是否为奇数行

[html] view plaincopy
<s:iterator value="days" status="offset">    
    <s:else>    
        <s:if test="#offset.odd==true">    
            <li style="color: red" mce_style="color: red"><s:property /></li>    
        </s:if>    
        <s:else>    
            <li><s:property /></li>    
        </s:else>    
    </s:else>    
</s:iterator>    

总结下，当声明iterator的status属性时，通过#statusName.method可以使用以下方法:

even : boolean - 如果当前迭代位置是偶数返回true
odd : boolean - 如果当前迭代位置是奇数返回true
count : int - 返回当前迭代位置的计数(从1开始)
index : int - 返回当前迭代位置的编号(从0开始)
first : boolean - 如果当前迭代位置是第一位时返回true
last : boolean - 如果当前迭代位置是最后一位时返回true
modulus(operand : int) : int - 返回当前计数(从1开始)与指定操作数的模数

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