HELLO WORLD--一起加油(🍺)!|

kingwzun

园龄:3年6个月粉丝:111关注:0

JAVA_Web JSTL_Core标签库使用

c:out

c:if

用法:

<c:if test="">
<%-- 标签体--%>
</c:if>
  • 如果test的计算结果为true,则执行标签体
  • 否则,不执行

c:choose

用法:

<c:choose>
<c:when test="">
<%-- 标签体--%>
</c:when>
<c:otherwise>
<%-- 标签体--%>
</c:otherwise>
</c:choose>
  • 如果when里面的test的计算结果为true,则该执行标签体
    • 否则,不执行
  • 如果全部when的条件都达不到,则输出otherwise的标签体

使用样例:

<%--
Created by IntelliJ IDEA.
User: WangWenZheng
Date: 2022/5/25
Time: 17:33
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<c:choose>
<c:when test="${empty param.username}">
unKnown user.
</c:when>
<c:when test="${param.username=='itcast'}">
${param.username} is manager.
</c:when>
<c:otherwise>
${param.username} is employee.
</c:otherwise>
</c:choose>
</body>
</html>

c:forEach

用法:

<c:forEach var="varname" items="collection" [begin="" end="" step=""] >
</c:forEach>

var:当前迭代到的元素的数据
items:用于迭代的集合对象
begin=""迭代的起始位置(默认从0开始)
end=""迭代的终止位置(包含该位置)
step=""步长
使用样例:

<%@ page import="java.util.HashMap" %>
<%@ page import="java.util.Map" %><%--
Created by IntelliJ IDEA.
User: WangWenZheng
Date: 2022/5/25
Time: 19:04
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<%
String[] fruits={"apple","orange","grange" ,"banana"};
%>
<br/>
<c:forEach var="name" items="<%=fruits%>">
${name}<br>
</c:forEach>
<%
Map userMap=new HashMap();
userMap.put("Tom","123");
userMap.put("Make","1234");
userMap.put("Lina","12345");
userMap.put("Tom2","123");
userMap.put("Make2","1234");
userMap.put("Lina2","12345");
%>
<hr/>
<br>
<c:forEach var="entry" items="<%=userMap%>" >
${entry.key} &nbsp;${entry.value} <br>
</c:forEach>
<hr/>
<br>
<c:forEach var="entry" items="<%=userMap%>" begin="1" end="5" step="2" >
${entry.key} &nbsp;${entry.value} <br>
</c:forEach>
</body>
</html>

c:param 和 c:url

本文作者:kingwzun

本文链接:https://www.cnblogs.com/kingwz/p/16310493.html

版权声明:本作品采用知识共享署名-非商业性使用-禁止演绎 2.5 中国大陆许可协议进行许可。

posted @   kingwzun  阅读(20)  评论(0编辑  收藏  举报
点击右上角即可分享
微信分享提示
评论
收藏
关注
推荐
深色
回顶
收起