<%@ page import="java.util.List" %>
<%@ page import="java.util.ArrayList" %>
<%@ page import="bean.User" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib uri="http://java.sun.com/jstl/core_rt" prefix="c"%>
<html>
<head>
<title>jstl</title>
</head>
<body>
<%-- jstl是jsp标准库 定制标签类的集合
核心标签库
格式化标签库 --%>
<%
request.setAttribute("num",10);
List<String > list=new ArrayList<String>();
for(int i=0;i<=10;i++){
list.add("A"+i);
}
pageContext.setAttribute("list",list);
%>
<%-- if标签 test必需 var存储结果 scope:var作用域 page/req/session/application--%>
<c:if test="${num>0}" scope="request" var="flag">
Hello JSTL
</c:if>
${flag}
<%-- choose when otherwise标签 相当于 switch case default
when otherwise 可以嵌套--%>
<c:choose >
<c:when test="${num>=20}">
num>=20
</c:when>
<c:when test="${num>=10&&num<20}">
num>=10
</c:when>
<c:otherwise>
num<10
</c:otherwise>
</c:choose>
<%-- forEach begin end step 相当于for()
var 变量名
items 要循环的数据
--%>
<c:forEach begin="0" end="10" step="1" var="i">
${i}<br>
</c:forEach>
<c:forEach items="${list}" var="data">
${data}<br>
</c:forEach>
<%
List<User> ulist=new ArrayList<User>();
User u1=new User("123","18");
User u2=new User("222","20");
ulist.add(u1);
ulist.add(u2);
request.setAttribute("ulist",ulist);
%>
<c:if test="${!empty ulist}">
<table align="center" width="800" border="1" style="border-collapse: collapse">
<tr>
<th>user name</th>
<th>user age</th>
</tr>
<c:forEach items="${ulist}" var="user">
<tr>
<th>${user.name}</th>
<th>${user.age}</th>
</tr>
</c:forEach>
</table>
</c:if>
</body>
</html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<%-- 格式化动作标签
formatNumber 将数值型转化为指定格式字符串
value 数值
type 格式化类型：number percent currency(货币)
var 接受格式化后内容 使用var 必须用$输出 --%>
<fmt:formatNumber value="10" type="currency" var="num" />${num}
<br>
<%
request.setAttribute("date",new Date());
%>
<%-- 格式化日期
pattern y M d H m s--%>
${date}<br>
<fmt:formatDate value="${date}" pattern="yyyy-MM-dd"/>
</body>
</html>
