JSTL(JSP标准标签库-JSP Standard Tag Library)：
<c:out>
<c:if>
<c:choose><c:when><c:otherwise>
<c:forEach>
<fmt:formatNumber>
<fmt:formatDate>
EL(EL表达式-Expression language):
index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<a href="servlet/JstlElServlet">jstl表达式</a>
<br>
</body>
</html>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<servlet-name>JstlElServlet</servlet-name>
<servlet-class>com.bjpowrnode.jstl.JstlElServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>JstlElServlet</servlet-name>
<url-pattern>/servlet/JstlElServlet</url-pattern>
</servlet-mapping>
</web-app>
JstlElServlet
/**
*
*/
package com.bjpowrnode.jstl;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @ClassName:JstlElServlet
* @Description:测试EL表达式
* @author wm
* @date 2016年2月14日下午8:45:38
*/
public class JstlElServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//普通字符串
request.setAttribute("hello", "Hello World");
request.getRequestDispatcher("/jstl_el.jsp").forward(request, response);;
}
}
jstl_el.jsp
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<!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=GB18030">
<title>Insert title here</title>
</head>
<body>
<h1>测试EL表达式</h1>
<hr>
<li>普通字符串</li><br>
hello(jsp脚本):<%=request.getAttribute("hello") %></br>
hello(El表达式：语法：$和{}:${hello}<br>
hello(el表达式，el内置对象， pageScope,requestScope,sessionScope,applicationScope )<br>
如果不指定范围，它的搜索范围就是pageScope~applicationScope():${requestScope.hello}<br>
hello(el表达式，从session中取得)：${sessionScope.hello}<br>
</body>
</html>
