2.获取值
1. el表达式只能从域对象中获取值
2. 语法:
1. ${域名称.键名}:从指定域中获取指定键的值
域名称:
1. pageScope --> pageContext
2. requestScope --> request
3. sessionScope --> session
4. applicationScope --> application(ServletContext)
举例:在request域中存储了name=张三
获取:${requestScope.name}
2. ${键名}:表示依次从最小的域中查找是否有该键对应的值,直到找到为止。
3. 获取对象、List集合、Map集合的值
1. 对象:${域名称.键名.属性名}
本质上会去调用对象的getter方法
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>el获取域中的数据</title> </head> <body> <% //在域中存储数据 session.setAttribute("name","李四"); request.setAttribute("name","张三"); session.setAttribute("age","23"); request.setAttribute("str",""); %> <h3>el获取值</h3> ${requestScope.name} ${sessionScope.age} ${sessionScope.haha} ${name} ${sessionScope.name} </body> </html>
<%@ page import="java.util.*" %> <%@ page import="com.example.domain.User" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>el获取数据</title> </head> <body> <% User user = new User(); user.setName("张三"); user.setAge(23); user.setBirthday(new Date()); request.setAttribute("u",user); List list = new ArrayList(); list.add("aaa"); list.add("bbb"); list.add(user); request.setAttribute("list",list); Map map = new HashMap(); map.put("sname","李四"); map.put("gender","男"); map.put("user",user); request.setAttribute("map",map); %> <h3>el获取对象中的值</h3> ${requestScope.u}<br> <%-- * 通过的是对象的属性来获取 * setter或getter方法,去掉set或get,在将剩余部分,首字母变为小写。 * setName --> Name --> name --%> ${requestScope.u.name}<br> ${u.age}<br> ${u.birthday}<br> ${u.birthday.month}<br> ${u.birStr}<br> <h3>el获取List值</h3> ${list}<br> ${list[0]}<br> ${list[1]}<br> ${list[10]}<br> ${list[2].name} <h3>el获取Map值</h3> ${map.gender}<br> ${map["gender"]}<br> ${map.user.name} </body> </html> ---------- package com.example.domain; import java.text.SimpleDateFormat; import java.util.Date; public class User { private String name; private int age; private Date birthday; public User(String name, int age, Date birthday) { this.name = name; this.age = age; this.birthday = birthday; } public User() { } /** * 逻辑视图 * @return */ public String getBirStr(){ if(birthday != null){ //1.格式化日期对象 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //2.返回字符串即可 return sdf.format(birthday); }else{ return ""; } } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } }
标签:EL,存储,name,el,age,获取,birthday,public From: https://www.cnblogs.com/agzq/p/17113418.html