<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.List" %><%--
User: 丁帅帅
Date: 21/05/30
Time: 10:00
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
${3>4}
\${3>4}
<hr>
<h3>算术运算符</h3>
${3+4}<br>
${3/4}<br>
${1 div 4}<br>
${3 % 4}<br>
${3 mod 4}<br>
<h3>比较运算符</h3>
${3 == 4}<br>
<h3>逻辑运算符</h3>
${3 > 4 && 3 < 4}<br>
${3 > 4 and 3 < 4}<br>
<h4>empty运算符</h4>
<%
String str="";
request.setAttribute("str",str);
List<Object> objects = new ArrayList<>();
request.setAttribute("list",objects);
%>
${empty str}
<br>
${not empty list}
</body>
</html>
<%--
User: 丁帅帅
Date: 21/05/30
Time: 10:23
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>el获取域中的数据</title>
</head>
<body>
<%
request.setAttribute("name","李四");
session.setAttribute("age",23);
%>
<h3>el获取值</h3>
${requestScope.name}
<br>
${sessionScope.age}
<br>
${name}
</body>
</html>
package com.ding.domain;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.SimpleFormatter;
/**
* @Description TODO
* @Author 丁帅帅
* @Date 21/05/30 10:28
* @Version 1.0
*/
public class User {
private String name;
private int age;
private Date birthday;
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;
}
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
return sdf.format(birthday);
}
return "";
}
}
<%@ page import="com.ding.domain.User" %>
<%@ page import="java.util.*" %><%--
User: 丁帅帅
Date: 21/05/30
Time: 10:39
To change this template use File | Settings | File Templates.
--%>
<%@ 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);
%>
<%--
* 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
--%>
<h3>el获取对象中的值</h3>
${requestScope.u}<br>
${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>
<%--
User: 丁帅帅
Date: 21/05/30
Time: 11:13
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>el隐式对象</title>
</head>
<body>
${pageContext.request}<br>
<h4>在jsp页面动态获取虚拟目录</h4>
${pageContext.request.contextPath}<br>
</body>
</html>