struts2标签遍历map集合

作者: 我被你的智商震惊的久久说不出话666
来源: 51数据库
2021-06-24

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="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

</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>

<s:iterator value="value">

</s:iterator>

</tr>

</s:iterator>

3.map中的value为string数组

<s:iterator value="arraymap" id="column">

<tr>

</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>

</tr>

</s:iterator>

struts2标签 遍历map集合

struts2标签遍历map集合