第 24講 struts2標籤-控制標籤
阿新 • • 發佈：2018-11-11
Struts2 控制標籤接上一節
Ifelse 標籤：條件判斷標籤；在request設定值，
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s"
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
int age=2;
request.setAttribute("age",age);
%>
</head>
<body>
<s:if test="#request.age
年齡小於20歲
</s:if>
<s:elseif test="#request.age==20">
年齡等於20歲
</s:elseif>
<s:else>
年齡大於20歲
</s:else>
</body>
</html>
Iterator 標籤：遍歷標籤；
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.cruise.model.Student" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
List<Student> studentList=new ArrayList<Student>();
studentList.add(new Student(1,"張三",10));
studentList.add(new Student(3,"李四",20));
studentList.add(new Student(5,"王五",30));
request.setAttribute("studentList",studentList);
%>
</head>
<body>
<table>
<tr>
<th>序號</th>
<th>編號</th>
<th>姓名</th>
<th>年齡</th>
</tr>
<s:iterator value="#request.studentList" status="status">
<tr>
<td><s:property value="#status.index+1"/></td>
<td><s:property value="id"/></td>
<td><s:property value="name"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</table>
</body>
</html>
Append 標籤：疊加標籤；將兩個List放在一起，形成一個List,前提是兩個List集合的物件有相同的屬性，合併之後才能在一起遍歷
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.cruise.model.Student" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
List<Student> studentList1=new ArrayList<Student>();
List<Student> studentList2=new ArrayList<Student>();
studentList1.add(new Student(1,"張三",10));
studentList1.add(new Student(3,"李四",20));
studentList2.add(new Student(5,"王五",30));
studentList2.add(new Student(7,"趙六",40));
request.setAttribute("studentList1",studentList1);
request.setAttribute("studentList2",studentList2);
%>
</head>
<body>
<s:append var="studentList3">
<s:param value="#request.studentList1"></s:param>
<s:param value="#request.studentList2"></s:param>
</s:append>
<table>
<tr>
<th>序號</th>
<th>編號</th>
<th>姓名</th>
<th>年齡</th>
</tr>
<s:iterator value="studentList3" status="status">
<tr>
<td><s:property value="#status.index+1"/></td>
<td><s:property value="id"/></td>
<td><s:property value="name"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</table>
</body>
</html>
Generator 標籤：分隔標籤；字串的分割，和split()方法一樣
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<s:generator separator="," val="'張三,李四,王五'" var="nameList"></s:generator>
<s:iterator value="#nameList">
<s:property/>
</s:iterator>
</table>
</body>
</html>
Merge 標籤：組合標籤；將兩個List集合混合，順序發生了變化。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.cruise.model.Student" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
List<Student> studentList1=new ArrayList<Student>();
List<Student> studentList2=new ArrayList<Student>();
studentList1.add(new Student(1,"張三",10));
studentList1.add(new Student(3,"李四",20));
studentList2.add(new Student(5,"王五",30));
studentList2.add(new Student(7,"趙六",40));
request.setAttribute("studentList1",studentList1);
request.setAttribute("studentList2",studentList2);
%>
</head>
<body>
<s:merge var="studentList3">
<s:param value="#request.studentList1"></s:param>
<s:param value="#request.studentList2"></s:param>
</s:merge>
<table>
<tr>
<th>序號</th>
<th>編號</th>
<th>姓名</th>
<th>年齡</th>
</tr>
<s:iterator value="studentList3" status="status">
<tr>
<td><s:property value="#status.index+1"/></td>
<td><s:property value="id"/></td>
<td><s:property value="name"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</table>
</body>
</html>
Sort 標籤：排序標籤；需要引入一個比較器，
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.cruise.model.Student" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
List<Student> studentList1=new ArrayList<Student>();
studentList1.add(new Student(1,"張三",20));
studentList1.add(new Student(3,"李四",10));
studentList1.add(new Student(5,"王五",40));
studentList1.add(new Student(7,"趙六",30));
request.setAttribute("studentList1",studentList1);
%>
</head>
<body>
<s:bean id="myComparator" name="com.cruise.comparator.MyComparator"></s:bean>
<table>
<tr>
<th>序號</th>
<th>編號</th>
<th>姓名</th>
<th>年齡</th>
</tr>
<s:sort comparator="#myComparator" source="#request.studentList1" >
<s:iterator status="status">
<tr>
<td><s:property value="#status.index+1"/></td>
<td><s:property value="id"/></td>
<td><s:property value="name"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</s:sort>
</table>
</body>
</html>
Subset 標籤：擷取標籤，類似與substring()方法，獲取List集合中的資料，
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.cruise.model.Student" %>
<%@ page import="java.util.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<%@taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<%
List<Student> studentList1=new ArrayList<Student>();
studentList1.add(new Student(1,"張三",20));
studentList1.add(new Student(3,"李四",10));
studentList1.add(new Student(5,"王五",40));
studentList1.add(new Student(7,"趙六",30));
request.setAttribute("studentList1",studentList1);
%>
</head>
<body>
<table>
<tr>
<th>序號</th>
<th>編號</th>
<th>姓名</th>
<th>年齡</th>
</tr>
<s:subset source="#request.studentList1" count="2" start="2">
<s:iterator status="status">
<tr>
<td><s:property value="#status.index+1"/></td>
<td><s:property value="id"/></td>
<td><s:property value="name"/></td>
<td><s:property value="age"/></td>
</tr>
</s:iterator>
</s:subset>
</table>
</body>
</html>