案例：对比使用Java代码与EL表达式获取信息

public class MyServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, 
      HttpServletResponse  response) throws ServletException, IOException {
		request.setAttribute("username", "itcast");
		request.setAttribute("password", "123");
         RequestDispatcher dispatcher = request
				.getRequestDispatcher("/myjsp.jsp");
		dispatcher.forward(request, response);
	}
	public void doPost(HttpServletRequest request,
      HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

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



    
	用户名：<%=request.getAttribute("username")%>
 
	密 码：<%=request.getAttribute("password")%>
	
	

	使用EL表达式:

	用户名：${username}

 	密 码：${password}

	

http://localhost:8080/chapter07/MyServlet

说明了java代码和EL表达式都能获取域对象中的存储的数据。但如果数据为null，EL返回空字符串，java代码返回null。