EL

21 Apr 2021

Reading time ~1 minute

EL(Expression Language)

표현 언어(Expression Language)는 값을 표현하는 데 사용되는 스크립트 언어로서 JSP의 기본 문법을 보완하는 역할

EL의 표현방법

EL의 기본객체

EL의 기본 객체 사용 예시

Scope별 EL 사용

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
    pageContext.setAttribute("p1", "page scope value");
    request.setAttribute("r1", "request scope value");
    session.setAttribute("s1", "session scope value");
    application.setAttribute("a1", "application scope value");
%>    
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
pageContext.getAttribute("p1") : ${pageScope.p1 }<br>
request.getAttribute("r1") : ${requestScope.r1 }<br>
session.getAttribute("s1") : ${sessionScope.s1 }<br>
application.getAttribute("a1") : ${applicationScope.a1 }<br>
<br><br>
pageContext.getAttribute("p1") : ${p1 }<br>
request.getAttribute("r1") : ${r1 }<br>
session.getAttribute("s1") : ${s1 }<br>
application.getAttribute("a1") : ${a1 }<br>

</body>
</html>

사칙연산 EL 사용

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
    request.setAttribute("k", 10);
    request.setAttribute("m", true);
%>    
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
k : ${k } <br>
k + 5 : ${ k + 5 } <br>
k - 5 : ${ k - 5 } <br>
k * 5 : ${ k * 5 } <br>
k / 5 : ${ k div 5 } <br>


k : ${k }<br>
m : ${m }<br>
k > 5 : ${ k > 5 } <br>
k < 5 : ${ k < 5 } <br>
k <= 10 : ${ k <= 10} <br>
k >= 10 : ${ k >= 10 } <br>
m : ${ m } <br>
!m : ${ !m } <br>

</body>
</html>