EL_获取域中存储的值
1.获取值：
1.el表达式只能从域对象获取值
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）
<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<html>
<head>
<title>el获取域中的数据</title>
</head>
<body>
<%
//域中存储数据
request.setAttribute("name", "张三");
session.setAttribute("age", "23");
%>
<h3>el获取值</h3>
${requestScope.name}
${sessionScope.age}
</body>
</html>
2.${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
<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<html>
<head>
<title>el获取域中的数据</title>
</head>
<body>
<%
session.setAttribute("name", "李四");
//域中存储数据
request.setAttribute("name", "张三");
session.setAttribute("age", "23");
%>
<h3>el获取值</h3>
${requestScope.name}
${sessionScope.age}
${sessionScope.name}
</body>
</html>
EL_获取域中存储对象值
1.获取对象：List集合，Map集合的值
1.对象：${域名称.键名.属性名}
本质上会去调用对象的getter方法
User实体类
package com.example.domain;
import java.text.SimpleDateFormat;
import java.util.Date;
public class User {
private String name;
private int age;
private Date birthday;
/**
* 逻辑视图
* @return
*/
public String getBitStr(){
if (birthday != null){
//1.格式化日期对象
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//2.返回字符串即可
return format.format(birthday);
}else {
return "";
}
}
@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
", 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;
}
}
jsp页面:
<%@ page import="com.example.domain.User" %>
<%@ page import="java.util.Date" %>
<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<html>
<head>
<title>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);
%>
<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.bitStr}<br>
</body>
</html>
标签：EL,存储,return,name,age,获取,birthday,public From： https://www.cnblogs.com/xuche/p/17081770.html