Java Web EL表达式

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" isELIgnored="false" import="com.xzit.domain.Student"%>


    
        
        
    
    <%
        String name = "Marke";
        pageContext.setAttribute("user_name",name);
        Student stu = new Student("岳不群",23);
        request.setAttribute("stuObj", stu);
    %>
    
        ${'张无忌'}

        ${56*2}

        从作用域中取出对象：${pageScope.user_name}

        <%--
        
        --%>
        请求EL.jsp

        请求ELServlet

        

            篮球
            足球
            排球

            
        
    

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


    
        
        
    
    
        从作用域中访问复合类型对象:${requestScope.stuObj.stuName}

        获取请求查询参数：${param.stuname} ${param.age}

        获取Cookie:${cookie['username'].name} ${cookie['username'].value}

        获取一个请求参数对应多个值的方式：

        第一个：${paramValues.likes[0]}

        第二个：${paramValues.likes[1]}

        第三个：${paramValues.likes[2]}

    

package com.xzit.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ELServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void service(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        
        Cookie cookies[] = request.getCookies();
        
        if(cookies!=null && cookies.length!=0){
            int count = 0;
            for(Cookie c:cookies){
                
                if(c.getName().equals("username")){
                    count++;
                    break;
                }
            }
            if(count==0){
                Cookie cookie = new Cookie("username","Zidane");
                cookie.setMaxAge(3600*24);
                response.addCookie(cookie);
            }
        }
    }

}

<?xml version="1.0" encoding="UTF-8"?>

  ELapp2
  
    index.jsp
  
  
      ELServlet
      ELServlet
      class>com.xzit.servlet.ELServletclass>
  
  
      ELServlet
      /ELServlet
  
  

package com.xzit.domain;

public class Student {
    private String stuName;
    private int age;
    public Student() {

    }
    

    public String getStuName() {
        return stuName;
    }


    public void setStuName(String stuName) {
        this.stuName = stuName;
    }


    public int getAge() {
        return age;
    }


    public void setAge(int age) {
        this.age = age;
    }


    public Student(String stuName, int age) {
        super();
        this.stuName = stuName;
        this.age = age;
    }
    
}