WEB开发的jsp例子标签库(jstl)的使用

2020-12-13 05:28
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标签：style class blog c code java
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@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

    request.setAttribute("attr_request","attr_request值");
    session.setAttribute("attr_session","attr_session值");
    application.setAttribute("attr_application","attr_application值");
%>
div>
div style="color:red;font-size:30px;">c:out标签的使用div>
div style="color:red">可以获取request，session，application的值div>
    parameter的值(得到不了)：c:out value="${name}"/>br />
    c:out value="${attr_request}"/>---${attr_request}br />
    c:out value="${attr_session}"/>---${attr_session}br />
    c:out value="${attr_application}"/>---${attr_application}br />
div>
hr />

    request.setAttribute("same_name","request值");
    session.setAttribute("same_name","session值");
    application.setAttribute("same_name","application值");
%>
div>
div style="color:red">相同名字的：request优先于session,session优先于applicationdiv>
    c:out value="${same_name}"/>br />
div>

hr />

    HashMap map = new HashMap();
    map.put("name","嵌套值");
    request.setAttribute("result",map);

    ArrayList list = new ArrayList();
    
    HashMap map1 = new HashMap();
    map1.put("name","张三");
    list.add(map1);
    
    HashMap map2 = new HashMap();
    map2.put("name","李四");
    list.add(map2);
    request.setAttribute("list",list);
%>
div>
div style="color:red">可以嵌套获取值，java也一样div>
    c:out value="${result.name}"/> --- ${result.name}br />
    c:out value="${list[0].name}"/>--- ${list[0].name}br />
    c:out value="${list[1].name}"/>---${list[1].name}br />
div>

body>
html>

@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

div style="color:red;font-size:30px;">条件判断标签的使用(c:if,c:shoose,c:when,c:otherwise)div>
hr />
div>
div style="color:red">c:if的使用div>

    request.setAttribute("result",true);
%>
c:set var="userName" value="张三"/>        
c:if test="${result == true}"  var="flag">
    欢迎${sessionScope.userName}光临!
c:if>
br />
你选择的答案：${flag}
hr />

HashMap map = new HashMap();
map.put("mark",1);
request.setAttribute("result1",map);
%>
br />
c:if test="${result1.mark == 1}">
    还可以通过嵌套使用
c:if>

hr />
div style="color:red">c:choose,when,otherwise的使用div>

request.setAttribute("month",2);
%>
    c:choose>
        c:when test="${month>0 && month>春c:when>
        c:when test="${month>3 && month>夏c:when>
        c:when test="${month>6 && month>秋c:when>
        c:when test="${month>9 && month>冬c:when>
        c:otherwise>错误c:otherwise>
    c:choose>
    
div>
hr />

body>
html>

@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

div style="color:red;font-size:30px;">循环标签的使用(c:forEach,c:fortokens)div>
hr />
div>
div style="color:red">c:forEach的使用div>

 
    ListString> list = new ArrayListString>();
    list.add("aaa1");
    list.add("aaa2");
    list.add("aaa3");
    request.setAttribute("list",list);
%>
    c:forEach items="${list}" var="str" varStatus="xh">
      ${xh.count}序号从1开始,
      ${xh.index}序号从0开始,
      ${xh.last}最后一个序号,
      ${xh.first}第一个序号,
      :${str}br/>
    c:forEach>
br />
hr />
div style="color:red">c:forEach的使用(空指针不会报错)div>
     request.setAttribute("list1",null);%>
    c:forEach items="${list1}" var="str">
        ${str}br/>
    c:forEach>
br />
hr />
div style="color:red">c:forEach的使用(数组使用)div>

    String[] nums = { "1", "2", "3", "4", "5", "6", "7", "8", "9"};
    request.setAttribute("nums",nums);
%>
    c:forEach items="${nums}" var="num">
    ${num}br />
    c:forEach>
br />
hr />
div style="color:red">c:forEach的使用(下标从0开始)div>
c:forEach items="${nums}" var="num" begin="1" end="7" step="2">
    ${num}br />
    c:forEach>
br />


div style="color:red">c:forEach的使用(数组使用)div>
 
        ArrayList array = new ArrayList();
        HashMap m = new HashMap();
        m.put("name","张三");
        array.add(m);
        m = new HashMap();
        m.put("name","李四");
        array.add(m);
        m = new HashMap();
        m.put("name","王五");
        array.add(m);
        m = new HashMap();
        m.put("name","赵六");
        array.add(m);
        m = new HashMap();
        m.put("name","林奇");
        array.add(m);
        request.setAttribute("result_list", array);
%>
 c:forEach items="${result_list}"  var="user">  
         ${user.name}br />
 c:forEach>  
 
br />
hr />
div style="color:red">c:forTokens的使用div>
c:forTokens items="a:b:c:d" delims=":" var="token">
    c:out value="${token}"/>
c:forTokens>
body>
html>

@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

div style="color:red;font-size:30px;">格式化标签的使用div>
hr />

div style="color:red">fmt:formatNumber的使用div>
    fmt:formatNumber value="0.3" type="number"/>br />
    fmt:formatNumber value="0.3" type="currency"/>br />
    fmt:formatNumber value="0.3" type="percent"/>br />
br />
hr />
div style="color:red">fmt:formatNumber的使用(精确小数点)div>
fmt:formatNumber value="12.31" pattern=".0000"/>br/>
fmt:formatNumber value="1245678.61" pattern="#"/>br/>
br />
hr />
div style="color:red">fmt:formatDate的使用div>
fmt:formatDate value="" />br/>
fmt:formatDate value="" type="time"/>br/>
fmt:formatDate value="" pattern="yyyy/MM/dd hh:mm:ss" />br />
fmt:formatDate value="" pattern="yyyy-MM-dd HH:mm:ss" />br />
fmt:formatDate value="" pattern="yyyy年MM月dd日 hh小时mm分钟ss秒" />br />
fmt:formatDate value="" pattern="yy/MM/dd hh:mm:ss" />br />

hr>


body>
html>

@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

div style="color:red;font-size:30px;">EL表达式使用div>
div style="color:red">算术运算符div>
hr />
加：1+1    = ${1+1}br/>
减：1-1    = ${1-1}br/>
乘：1*2    = ${1*2}br/>
除：    3/2 = ${3/2}br/>
模：    3%2 = ${3%2}br/>
div style="color:red">关系运算符div>
hr />
1==1:${1==1}br/>
1!=1:${1!=1}br/>
12:${1/>
1>2:${1>2}br/>
1=2:${1=2}
/>
1>=2:${1>=2}br/>
div style="color:red">逻辑运算符div>
hr />
 
request.setAttribute("a",true);
request.setAttribute("b",false);
%>
a=true,b=falsebr/>
${a && b}br/>
${a || b}br/>
${!a}br/>

div style="color:red">三元运算符div>
hr />
1 > 1 ? "真" : "假" = ${1 > 1 ? "真" : "假"}

div style="color:red">empty会帮你判断size=0的情况div>
hr />
 request.setAttribute("list",new  ArrayList());%>
c:if test="${empty list}">empty判断list没有数据c:if>
body>
html>


@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
@ page import="java.util.*" %>
DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
title>Insert title heretitle>
head>
body>

div style="color:red;font-size:30px;">set,remove,catch 标签使用div>
div style="color:red">set的使用div>
hr />
 c:set var="userName" value="张三" scope="request" />
 c:set var="userName" value="李四" scope="session" />
 c:set var="userName" value="王五" scope="application" />
 =request.getAttribute("userName") %>br/>
 =session.getAttribute("userName") %>br/>
 =application.getAttribute("userName") %>br/>
 
br/>
div style="color:red">remove的使用div>
hr />
 c:remove var="userName" scope="request" />
 c:remove var="userName" scope="session" />
 c:remove var="userName" scope="application" />
 remove后的值：=request.getAttribute("userName") %>br/>
  remove后的值：=session.getAttribute("userName") %>br/>
  remove后的值：=application.getAttribute("userName") %>br/>
 br/>
 
div style="color:red">catch的使用div>
hr />
c:catch var="error_Message">  
  
    int i = Integer.parseInt("a");  
%>  
c:catch>  
${error_Message}  
body>
html>