Struts2 使用OGNL遍历map方法详解

发布时间：2020-12-14 22:23:50 所属栏目：Java 来源：网络整理

导读：一.Action中的代码：MapAction.java package com.zx.demo.action;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import com.opensymphony.xwork2.ActionSupport;import com.zx.demo.model.Product;impor

一.Action中的代码：MapAction.java

package com.zx.demo.action;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.opensymphony.xwork2.ActionSupport;
import com.zx.demo.model.Product;
import com.zx.demo.model.Student;
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;  
 //这里省略get set方法
 public String testMap(){  
map=new HashMap<String,String>();
 map.put("1","one");
 map.put("2","two");
studentMap=new HashMap<String,Student>();
studentMap.put("student1",new Student(new Long(1),"20034140201","张三1","男",25));
studentMap.put("student2",new Student(new Long(2),"20034140202","张三2","女",26));
studentMap.put("student3",new Student(new Long(3),"张三3",27));
arrayMap=new HashMap<String,String[]>();
arrayMap.put("arr1",new String[]{"1","2003401","leejie","male","20"});
arrayMap.put("arr2",new String[]{"2","2003402","huanglie","25"});
arrayMap.put("arr3",new String[{"3","2003403","lixiaoning","21"});
listMap=new HashMap<String,List<Student>>();
  List<Student> list1=new ArrayList<Student>();
list1.add(new Student(new Long(1),25));
list1.add(new Student(new Long(2),25));
list1.add(new Student(new Long(3),"20034140203",25));
  listMap.put("class1",list1);
 List<Student> list2=new ArrayList<Student>();
list2.add(new Student(new Long(1),"20034140301","李四1",20));
list2.add(new Student(new Long(2),"20034140302","李四2",21));
list2.add(new Student(new Long(3),"20034140303","李四3",22));
list2.add(new Student(new Long(4),"20034140304","李四4",23));
  listMap.put("class2",list2);
return SUCCESS;  
  }  
}

二.前端测试页面：testMap.jsp

Java代码

<%@ 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key为String，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> 
******************************************<br>
 <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>
******************************************<br>
 <b>2.map中的key为String，value为Student对象</b>
<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.num"/></td>
 <td>
  <s:property value="value.name"/></td>
 <td>
   <s:property value="value.sex"/></td>
 <td>
   <s:property value="value.age"/></td>
 </tr>
</s:iterator>
</table>
 <p> 
 
<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>
******************************************<br>
<b>3.map中的key为String，value为String数组</b> 
<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> 
<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>
 ******************************************<br>
<b>4.map中的key为String，value为list集合</b>  
<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>

附：map的类型为Map<Integer,List(Menu)>在前端遍历，session.powerList存放的类型是：List（Menu）

<s:iterator value="map" id="mapList">
   <s:if test="#mapList.key==0"><!-key为0的是父级菜单->
   <s:iterator value="#mapList.value" id="map">
    <li class="current"><!--遍历父级菜单，取得其名字-->  
   <b><s:property value="#map.menuName" /></b></a>
     <ul>
     <s:iterator value="#session.powerList" id="power">
   <!--遍历父级菜单下的所用子菜单-->
      <s:if test="#power.menuFatherId==#map.menuId">
    <li><a onClick="funFrame('admin/<s:property value="#power.menuUrl" />')" ><s:property value="#power.menuName" /></a>
    </li>
       </s:if>
     </s:iterator>
     </ul>
     </li>
     </s:iterator>
     </s:if>
     </s:iterator>

总结

以上就是本文关于Struts2 使用OGNL遍历map方法详解的全部内容，希望对大家有所帮助。有兴趣的朋友可以参阅：OGNL表达式基本语法与用法详解 Struts2 通过ognl表达式实现投影 Struts2 OGNL表达式实例详解等。感谢大家对本站的支持。

（编辑：李大同）

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