Struts2的标签三大类是什么？

时间：2019-05-28 23:36:53 阅读：150 评论：0 收藏：0 [点我收藏+]

Struts2 标签

一 Struts标签的简介：

　　Struts2 自己封装了一套标签，比 JSTL 强大，而且与 Struts2 中的其他功能无缝结合。当然 Strust2 标签的内容很多，随着版本的升级，标签和属性越来越多。我们要掌握好核心标签及了解其他标签；根据功能可以分为：数据标签，控制标签，界面标签，其他标签；(其实如果学过标准标签库stl基本上这部分内容简单的一批)

二 Struts2 数据标签

Property 标签：输出 OGNL 表达式的值；取值

1 <% request.setAttribute("name","<font color=‘red‘ >张三</font>"); %>
2 <body>
3     <h1>property</h1>
4     <s:property value="#request.name"/><br/>
5     <s:property value="#request.name2" default="某某"/><br/>
6     <s:property value="#request.name" escapeHtml="false"/><br/>
7 </body>

Set 标签：设置变量；

 1 <h1>set标签</h1>
 2     <s:set var="i" value="1"/><br/>
 3     i= <s:property value="#i"/><br/>
 4     <s:set var="a" value="‘action的值类似于值栈（value-stack）‘" scope="action"></s:set>
 5     <s:set var="p" value="‘page的值‘" scope="page"></s:set>
 6     <s:set var="re" value="‘request值‘" scope="request"></s:set>
 7     <s:set var="se" value="‘session值‘" scope="session"></s:set>
 8     <s:set var="app" value="‘application值‘" scope="application"></s:set>
 9     action:<s:property value="#a"/><br/>
10     page:<s:property value="#attr.p"/><br/>
11     request:<s:property value="#request.re"/><br/>
12     session:<s:property value="#session.se"/><br/>
13     application:<s:property value="#application.app"/><br/>

Bean 标签：定义 javaBean 对象；

1 <h1>bean标签</h1>
2     <s:bean name="com.java1234.model.Student" var="student">
3         <s:param name="name" value="‘张三‘"></s:param>
4         <s:param name="age" value="18"></s:param>
5     </s:bean>
6     name:<s:property value="#student.name"/><br/>
7     age:<s:property value="#student.age"/><br/>

Date 标签：日期标签；

1 <%  request.setAttribute("date", new Date());  %>
2 <body>
3     <h1>Date标签</h1>
4     日期：&nbsp;&nbsp; ${date }<br/>
5     日期：&nbsp;&nbsp; <s:date name="#request.date" format="yyyy-MM-dd"/>
6 </body>

Debug 标签：调试标签；

1 <h1>Debug标签</h1>
2 <s:debug></s:debug>

Url&a 标签：超链接标签；

1 <s:a action="hello" namespace="/forgroud" >
2 
3 <s:param name="name" value="‘struts2‘"></s:param>
4 
5 链接a
6 
7 </s:a>

Include 标签：动态包含标签；

1 <s:include value="head.html"></s:include>

三 Struts2 控制标签

Ifelse 标签：条件判断标签；

 1 <% int age=11;   request.setAttribute("age", age);    %>
 2 <body>
 3     <h1>if else标签</h1>
 4      年龄：<s:property value="#request.age"/>  
 5     <s:if test="#request.age<18">
 6       小于18岁 
 7     </s:if>
 8     <s:elseif test="#request.age<30">
 9           大于18岁    小于30岁 
10     </s:elseif>
11     <s:else>
12         大于30岁
13     </s:else>
14 </body>

Iterator 标签：遍历标签；

 1 <%
 2     List<Student>studentList=new ArrayList<Student>();
 3     studentList.add(new Student(1,"张三",18));
 4     studentList.add(new Student(2,"李四",19));
 5     studentList.add(new Student(5,"王五",25));
 6     request.setAttribute("studentList", studentList);
 7 %>
 8 <body>
 9     <h1>iterator</h1>
10     <table border="1">
11         <tr>
12             <th>序号</th>
13             <th>学号</th>
14             <th>姓名</th>
15             <th>年龄</th>
16         </tr>
17         <s:iterator value="#request.studentList" var="sl" status="status">
18         <tr>
19             <td><s:property value="#status.index+1"/></td>
20             <td><s:property value="id"/></td>
21             <td><s:property value="name"/></td>
22             <td><s:property value="age"/></td>
23         </tr>
24         </s:iterator>
25     </table>
26 </body>

Append 标签：叠加标签；

 1 <%
 2     List<Student>studentList=new ArrayList<Student>();
 3     List<Student>studentList1=new ArrayList<Student>();
 4     studentList.add(new Student(1,"张三",18));
 5     studentList.add(new Student(2,"李四",19));
 6     studentList.add(new Student(5,"王五",25));
 7     studentList1.add(new Student(6,"赵六",27));
 8     studentList1.add(new Student(7,"小七",28));
 9     request.setAttribute("studentList", studentList);
10     request.setAttribute("studentList1", studentList1);
11 %>
12 <body>
13     <s:append var="studentList2">
14         <s:param value="#request.studentList"></s:param>
15         <s:param value="#request.studentList1"></s:param>
16     </s:append>
17     <h1>iterator</h1>
18     <table border="1">
19         <tr>
20             <th>序号</th>
21             <th>学号</th>
22             <th>姓名</th>
23             <th>年龄</th>
24         </tr>
25         <s:iterator value="#request.studentList2" var="sl" status="status">
26         <tr>
27             <td><s:property value="#status.index+1"/></td>
28             <td><s:property value="id"/></td>
29             <td><s:property value="name"/></td>
30             <td><s:property value="age"/></td>
31         </tr>
32         </s:iterator>
33     </table>
34 </body>

Generator 标签：分隔标签；

1 <s:generator separator="," val="‘张三,李四,王五‘" var="nameList"></s:generator>
2 　　<s:iterator value="#nameList">
3       <s:property/>
4    </s:iterator>

Merge 标签：组合标签；

Sort 标签：排序标签；我们使用一个简单的例子学习一下：

Model:Student类：

 1 public class Student {
 2     private String name;
 3     private int id;
 4     private int age;
 5     public Student() {
 6         super();
 7         // TODO Auto-generated constructor stub
 8     }
 9     public Student( int id, String name,int age) {
10         super();
11         this.name = name;
12         this.id = id;
13         this.age = age;
14     }
15     public String getName() {
16         return name;
17     }
18     public void setName(String name) {
19         this.name = name;
20     }
21     public int getId() {
22         return id;
23     }
24     public void setId(int id) {
25         this.id = id;
26     }
27     public int getAge() {
28         return age;
29     }
30     public void setAge(int age) {
31         this.age = age;
32     }
33 }

排序类：com.java1234.compator.MyComparator代码：

 1  public class MyComparator  implements Comparator<Student>{
 2     public int compare(Student s1,Student s2){
 3         if(s1.getAge()>s2.getAge()){
 4             return 1;
 5         }else if(s1.getAge()<s2.getAge()){
 6             return -1;
 7         }else{
 8             return 0;
 9         }
10     }
11 }

 1 <%
 2     List<Student>studentList=new ArrayList<Student>();
 3     studentList.add(new Student(1,"张三",18));
 4     studentList.add(new Student(2,"李四",19));
 5     studentList.add(new Student(5,"王五",25));
 6     studentList.add(new Student(6,"王五",17));
 7     studentList.add(new Student(7,"王五",19));
 8     request.setAttribute("studentList", studentList);
 9 %>
10 <body>
11     <h1>iterator</h1>
12     <s:bean id="Mycomparator" name="com.java1234.compator.MyComparator"></s:bean>
13     <table border="1">
14         <tr>
15             <th>序号</th>
16             <th>学号</th>
17             <th>姓名</th>
18             <th>年龄</th>
19         </tr>
20         <s:sort comparator="#Mycomparator" source="#request.studentList">
21             <s:iterator status="status">
22             <tr>
23                 <td><s:property value="#status.index+1"/></td>
24                 <td><s:property value="id"/></td>
25                 <td><s:property value="name"/></td>
26                 <td><s:property value="age"/></td>
27             </tr>
28             </s:iterator>
29          </s:sort>
30     </table>

Subset 标签：截取标签；

 1 <%
 2     List<Student>studentList=new ArrayList<Student>();
 3     studentList.add(new Student(1,"张三",18));
 4     studentList.add(new Student(2,"李四",19));
 5     studentList.add(new Student(5,"王五",25));
 6     studentList.add(new Student(6,"赵六",28));
 7     request.setAttribute("studentList", studentList);
 8 %>
 9 <body>
10     <h1>subset</h1>
11     <table border="1">
12         <tr>
13             <th>序号</th>
14             <th>学号</th>
15             <th>姓名</th>
16             <th>年龄</th>
17         </tr>
18         <s:subset source="#request.studentList" start="2" count="2">
19             <s:iterator status="status">
20             <tr>
21                 <td><s:property value="#status.index+1"/></td>
22                 <td><s:property value="id"/></td>
23                 <td><s:property value="name"/></td>
24                 <td><s:property value="age"/></td>
25             </tr>
26             </s:iterator>
27         </s:subset>
28     </table>
29 </body>

四 Strut2 界面标签

Form 标签：表单提交标签；

1 <s:form method="post" action="hello" namespace="/forgroud">提交内容</s:form>

Text 标签：文本标签；

1 用户名：<s:textfield name="name"></s:textfield>
2 密码：<s:password name="password"></s:password>
3 备注：<s:textarea name="desc"></s:textarea>

Radios 标签：单选标签；

1 性别单选框： <s:radio list="#{0:‘男‘,1:‘女‘ }" name="sex" value="0"></s:radio>