获取域中存储的值和获取域中存储的值对象值
作者:互联网
获取域中存储的值
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。
${name}
<%@ 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"); %> <h3>获取值</h3> ${requestScope.name} ${sessionScope.age} ${sessionScope.haha} ${name} </body> </html>
获取域中存储的值对象值
获取对象、List集合、Map集合的值
1.对象:${域名称.键名.属性名}
本质上会去调用对象的getter方法
User对象
package com.peng.request.demo.domain; import java.text.SimpleDateFormat; import java.util.Date; public class User { private String name; private int age; private Date birthday; public String getBirStr(){ if (birthday!=null){ //格式化日期对象 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //返回字符串 return sdf.format(birthday); }else { return ""; } } public User() { } public User(String name, int age, Date birthday) { this.name = name; this.age = age; this.birthday = birthday; } 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; } }
js页面:
<%@ page import="com.peng.request.demo.domain.User" %> <%@ page import="java.util.Date" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>el获取对象数据</title> </head> <body> <% User user = new User(); user.setName("张三"); user.setAge(23); user.setBirthday(new Date()); request.setAttribute("u",user); %> <h3>el获取对象中的值</h3> ${requestScope.u}<br> <%-- 通过对象的属性来获取 setter或getter,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} </body> </html>
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标签:存储,return,name,对象,age,获取,birthday,public 来源: https://www.cnblogs.com/pengtianyang/p/16588456.html