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

秒客网

JSTL学习笔记(核心标签)

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