struts2标签遍历map集合

待我称王封你为后i 2022-09-17 13:20 176阅读 0赞

首先我们来构造几个map集合。

假设如下代码 都是在ssh配置环境下搭建好，(至少struts2开发环境搭建好)

(1).java 代码

下面的student对象包含的字段为

private Long id;  
private String num;  
private String name;  
private String sex;  
private Integer age;

Action中的代码

private Map<String,String> map; 
 private Map<String,Student> studentMap; 
private Map<String,String\[\]> arrayMap; 
private Map<String,List<Student>> listMap; // 实现 四个map对象的get 和set方法。

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),"20034140202","张三3","男",27)); 
 
 arrayMap=new HashMap<String,String\[\]>(); 
 arrayMap.put("arr1", new String\[\]\{"1","2003401","leejie","male","20"\}); 
 arrayMap.put("arr2", new String\[\]\{"2","2003402","huanglie","male","25"\}); 
 arrayMap.put("arr3", new String\[\]\{"3","2003403","lixiaoning","male","21"\}); 
 
 
 
 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); 
 
 List<Student> list2=new ArrayList<Student>(); 
 list2.add(new Student(new Long(1),"20034140301","李四1","男",20)); 
 list2.add(new Student(new Long(2),"20034140302","李四2","男",21)); 
 list2.add(new Student(new Long(3),"20034140303","李四3","男",22)); 
 list2.add(new Student(new Long(4),"20034140304","李四4","男",23)); 
 listMap.put("class2", list2);

(2).通过上述java代码我们已经构建好了4个map集合。 接下来的重头戏就是如何通过strut2的标签来获取map集合中的值。

1.map中的value为String字符串

<s:iterator value="map" id="column"> 
<s:property value="\#column"/> //这里获取到的值为key=value 即：键值对 
key: <s:property value="key"/> //这里的key为内置的，我们只要在value中写上key 即会有值 
value:<s:property value="value"/> //同样这里的value也为内置的 
</s:iterator> 
 
 2.map中的value为Student对象 
 <s:iterator value="studentMap" id="column"> 
 <tr> 
 <td><s:property value="\#column"/></td> 
 <td><s:property value="key"/></td> 
 <td><s:property value="value"/></td> //这里的value返回的是一个student对象 
 <td><s:property value="value.id"/></td> //这里获取student对象中的属性值 
 <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>

遍历studentMap 还可以用下面方式，跟上面方式效果是一样的

2.map中的value为Student对象 
 <s:iterator value="studentMap" id="column"> 
 <tr> 
 <td><s:property value="\#column"/></td> 
 <td><s:property value="key"/></td> 
 <s:iterator value="value"> 
 <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> 
 </s:iterator> 
 </tr> 
 </s:iterator>

3.map中的value为String数组 
 <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> 
 
 4.map中的value为list集合 
 <s:iterator value="listMap" id="column"> 
 <s:set name="total" value="\#column.value.size"/> //注意<s:set 标签的用法 
 <s:iterator value="\#column.value" status="s"> //这里\#column.value 还是一个student的list集合，因而需要再次迭代一次 
 <tr> 
 <s:property value="\#s.first"/> //判断是不是集合中的第一个对象 
 <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>