JSP Expression Language (EL): Syntax, Operators and Examples

What is Expression Language?

JSP Expression Language (EL) reads values prepared by a servlet, controller, or tag and renders them with concise ${...} expressions.

EL can access JavaBean properties, maps, lists, request parameters, headers, cookies, and page, request, session, or application attributes without embedding Java scriptlets in the view.

Use explicit scope names when the same attribute could exist in more than one scope, and use the empty operator for safe null, empty string, array, collection, and map checks.

JSP Expression Language uses `${expression}` to read scoped attributes, bean properties, collections, request parameters, and supported functions without embedding Java scriptlets. EL support requires JSP 2.0 or later.

EL makes JSP pages cleaner and easier to maintain by eliminating verbose Java code like <%= (String) session.getAttribute("user") %> and replacing it with ${sessionScope.user}.

EL Implicit Objects

EL Object	Type	Description
param	Map<String,String>	Request parameters (single value)
paramValues	Map<String,String[]>	Request parameters (multiple values)
header	Map<String,String>	HTTP request headers
headerValues	Map<String,String[]>	HTTP headers (multiple values)
cookie	Map<String,Cookie>	Cookies from the request
pageScope	Map	Page-scoped attributes
requestScope	Map	Request-scoped attributes
sessionScope	Map	Session-scoped attributes
applicationScope	Map	Application-scoped attributes
initParam	Map	Context init parameters from web.xml
pageContext	PageContext	Access to JSP page context

EL Syntax and Implicit Objects

<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%
    // Set attributes in different scopes
    request.setAttribute("message", "Hello from Request!");
    session.setAttribute("username", "Alice");
    session.setAttribute("age", 25);
    application.setAttribute("appVersion", "2.0");
%>
<html><body>

<h3>Accessing Scoped Attributes</h3>
<p>Request: ${requestScope.message}</p>
<p>Session username: ${sessionScope.username}</p>
<p>Session age: ${sessionScope.age}</p>
<p>App version: ${applicationScope.appVersion}</p>

<%-- EL searches all scopes automatically (page, request, session, app) --%>
<p>Auto-search: ${username}</p>

<h3>Request Parameters</h3>
<p>Name param: ${param.name}</p>
<p>Age param: ${param.age}</p>

<h3>Headers and Cookies</h3>
<p>User-Agent: ${header['User-Agent']}</p>
<p>Cookie value: ${cookie.JSESSIONID.value}</p>

<h3>pageContext</h3>
<p>Context path: ${pageContext.request.contextPath}</p>
<p>Server name: ${pageContext.request.serverName}</p>

</body></html>

EL Operators

EL supports arithmetic, relational, logical, and the empty operator:

EL Operators - Java Example

<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html><body>

<h3>Arithmetic Operators</h3>
<p>10 + 5 = ${10 + 5}</p>
<p>10 - 3 = ${10 - 3}</p>
<p>4 * 3 = ${4 * 3}</p>
<p>10 / 3 = ${10 / 3}</p>
<p>10 mod 3 = ${10 mod 3}</p>

<h3>Relational Operators</h3>
<p>5 == 5: ${5 == 5}</p>
<p>5 != 3: ${5 != 3}</p>
<p>10 > 5: ${10 gt 5}</p>
<p>3 < 7: ${3 lt 7}</p>
<p>5 >= 5: ${5 ge 5}</p>

<h3>Logical Operators</h3>
<p>true && false: ${true and false}</p>
<p>true || false: ${true or false}</p>
<p>!true: ${not true}</p>

<h3>Empty Operator</h3>
<p>Is null empty: ${empty null}</p>
<p>Is "" empty: ${empty ""}</p>
<p>Is "hello" empty: ${empty "hello"}</p>

<h3>Ternary / Conditional</h3>
<p>${param.age gt 18 ? "Adult" : "Minor"}</p>

</body></html>

Servlet prepares data for JSP EL

request.setAttribute("pageTitle", "Order summary");
request.setAttribute("order", orderService.find(orderId));
request.getRequestDispatcher("/WEB-INF/views/order.jsp")
       .forward(request, response);

JSP reads properties and handles missing data

<h1>${requestScope.pageTitle}</h1>

<c:choose>
  <c:when test="${empty requestScope.order}">
    <p>Order not found.</p>
  </c:when>
  <c:otherwise>
    <p>Order: <c:out value="${order.id}" /></p>
    <p>Total: ${order.total}</p>
  </c:otherwise>
</c:choose>

Before you move on