JSTL学习笔记(核心标签)

一、JSTL标签分类：

核心标签　　
格式化标签
SQL标签
XML标签
JSTL函数

二、核心标签引用方式：<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

1.<c:out>可使用“.”符号来访问属性。例如，要访问customer.address.street 只使用标签<c:out value="customer.address.street"/>。<c:out>具有三个属性，value，default(Fallback)，escapeXML。

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>JSTL Study</title>
  </head>
  <body>
      this is c:out
      <br>
    <c:out value="exciting"/>
  </body>
</html>

2.<c:set>，具有以下属性：value，target，property，var，scope，<c:remove>具有(var,scope)属性

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
  <head>
    <base href="<%=basePath%>">
    <title>JSTL Study</title>
  </head>
  <body>
      this is c:set
    <br>
    <c:set var="example" scope="session" value="${2000*2}"/><br>
    <c:out value="${example}"/><br>
    <c:remove var="example"/>
    <p>After Remove</p>
    <c:out value="${example}"/>
    <c:out value="${message.id}"/><br>
    <c:set target="${message}" property="id" value="123456"/>
    <c:out value="${message.id}"/>&nbsp;&nbsp;<c:out value="${message.content }" />&nbsp;&nbsp;<c:out value="${message.description }" />&nbsp;&nbsp;<c:out value="${message.command }" />
  </body>
</html>

3.<c:catch>捕获错误，<c:if>具有(test,var,scope)属性，test:条件计算，var:变量名称来存储条件的结果，scope:变量的范围来存储条件的结果

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
  <head>
    <base href="<%=basePath%>">
    <title>JSTL Study</title>
  </head>
  <body>
    <c:catch var="catchException">
    <%
        int x = 5/0;
     %>
    </c:catch>
    <c:if test = "${catchException != null}">
      <p>The exception is : ${catchException} <br />
       There is an exception: ${catchException.message}</p>
    </c:if>
  </body>
</html>

4.<c:choose>就像switch语句。switch有case，<c:choose>有<c:when>。switch有default，<c:choose>有<c:otherwise>

<c:choose>
    <c:when test="${age <= 18}">
       Kid
    </c:when>
    <c:when test="${age> 18}">
       Not Kid
    </c:when>
    <c:otherwise>
       Illegal
    </c:otherwise>
</c:choose>

5.<c:import>导入功能，具有(url,context,charEncoding,var,scope,varReader)属性

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
  <head>
    <base href="<%=basePath%>">
    <title>JSTL Study</title>
  </head>
  <body>
    <c:import var="data" url="http://www.baidu.com" />
    <c:out value="${data}"/>
  </body>
</html>

6.<c:forEach>遍历对象的集合。<c:forTokens>类似于split

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<html>
  <head>
    <base href="<%=basePath%>">   
    <title>JSTLStudy</title>
  </head>
  
  <body>
    ForEach and ForTokens<br>
    <c:forEach items = "${MessageList}" var="mes">
      <c:out value="${mes.command}"/>&nbsp;
    </c:forEach>
    <c:forTokens items="a,b,c" delims="," var="name">
      <c:out value="${name}"/><p>
    </c:forTokens>
  </body>
</html>

7.<c:param>标签允许适当的URL请求参数并在URL中指定。<c:url>标记格式的URL转换为字符串，并将其存储到一个变量

<c:url value="/index.jsp" var="myURL">
   <c:param name="trackingId" value="1234"/>
   <c:param name="reportType" value="summary"/>
</c:url>
<c:import url="${myURL}"/>

8.<c:redirect>标签提供自动URL重写将浏览器重定向到另一个URL，它支持上下文相关的URL，并且它支持<c:param>标签。

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<html>
  <head>
    <base href="<%=basePath%>">   
    <title>JSTLStudy</title>
  </head>
  
  <body>
    <c:redirect url="http://www.baidu.com"/>
  </body>
</html>

感谢http://www.yiibai.com/jsp/jsp_standard_tag_library.html

posted @ 2016-05-09 16:37 lastword 阅读(186) 评论(0) 收藏举报

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JSTL学习笔记(核心标签)

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