Spring项目结构

package com.layne.my.shop.common.context;

import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;


public  class SpringContext implements ApplicationContextAware, DisposableBean {

    private static  final Logger logger = LoggerFactory.getLogger(SpringContext.class);

    private static ApplicationContext applicationContext;

    /**
     * 获取存储在静态变量中的 ApplicationContext
     * @return
     */
    public static ApplicationContext getApplicationContext() {
        assertContextInjected();
        return applicationContext;
    }

    /**
     * 使用ApplicationContext,根据BeanId获取实例
     * @param beanId
     * @param <T>
     * @return
     */
    public  static <T> T getBeanExample(String beanId){
        assertContextInjected();
        return (T) applicationContext.getBean(beanId);
    }
    /**
     * 使用ApplicationContext,根据BeanId获取实例
     * @param clazz
     * @param <T>
     * @return
     */
    public static <T> T getBeanExample(Class<T> clazz){
        assertContextInjected();
        return applicationContext.getBean(clazz);
    }

    @Override
    public void destroy() throws Exception {
         logger.debug("清空ApplicationContext");
        applicationContext=null;
    }
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContext.applicationContext=applicationContext;
    }
   /* public Object getBean(String beanId){
        ApplicationContext context=new ClassPathXmlApplicationContext("spring-context.xml");
        return context.getBean(beanId);
    }*/

    /**
     * 断言容器【ApplicationContext】已经注入
     * public static void validState(boolean expression, String message, Object... values) {
     *         if (!expression) {
     *             throw new IllegalStateException(String.format(message, values));
     *         }
     *     }
     *
     *     1.applicationContext!=null----->applicationContext为空---->applicationContext!=null【false】------>!expression【true】
     *     2.applicationContext==null----->applicationContext为空---->applicationContext!=null【true】------>!expression【false】
     */
    private  static void assertContextInjected(){
        Validate.validState(applicationContext!=null,"你还没有在spring-context.xml中配置SpringContext对象");
    }
}

　POM.XML

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.layne</groupId>
    <artifactId>my-shop</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
          <slf4j.version>1.7.25</slf4j.version>
          <log4j.version>1.2.17</log4j.version>
          <spring.version>4.3.17.RELEASE</spring.version>
          <servlet-api.version>4.0.1</servlet-api.version>
         <commons-lang3>3.5</commons-lang3>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>${servlet-api.version}</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jul-to-slf4j</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>${commons-lang3}</version>
        </dependency>

    </dependencies>

</project>

　　WEB.XML

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-context*.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <servlet>
        <servlet-name>LoginController</servlet-name>
        <servlet-class>com.layne.my.shop.web.controller.LoginController</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LoginController</servlet-name>
        <url-pattern>/login</url-pattern>
    </servlet-mapping>
</web-app>

　　INDEX.JSP

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<!--Head Begin-->
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>我的商城 | 登录</title>
    <!-- Tell the browser to be responsive to screen width -->
    <meta content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" name="viewport">
    <!-- Bootstrap 3.3.7 -->
    <link rel="stylesheet" href="assets/bower_components/bootstrap/dist/css/bootstrap.min.css"/>
    <!-- Font Awesome -->
    <link rel="stylesheet" href="assets/bower_components/font-awesome/css/font-awesome.min.css"/>
    <!-- Ionicons -->
    <link rel="stylesheet" href="assets/bower_components/Ionicons/css/ionicons.min.css"/>
    <!-- Theme style -->
    <link rel="stylesheet" href="assets/css/AdminLTE.min.css"/>
    <!-- iCheck -->
    <link rel="stylesheet" href="assets/plugins/iCheck/square/blue.css"/>
</head>
<!--Head end-->
<body class="hold-transition login-page">
<div class="login-box">
    <div class="login-logo">
        <a href="#">我的商城</a>
    </div>
    <!-- /.login-logo -->
    <div class="login-box-body">
        <p class="login-box-msg">欢迎管理员登录</p>
        <form action="/login" method="post">
               <%--<c:if test="${message != null}">
                <div class="alert alert-danger alert-dismissible">
                    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
                     ${message}
                </div>
               </c:if>--%>
                <div class="alert alert-danger alert-dismissible" ${message==null?"style='display: none'":""}>
                    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
                        ${message}
                </div>
            <div class="form-group has-feedback">
                <input type="email" class="form-control" name="email" placeholder="邮箱">
                <span class="glyphicon glyphicon-envelope form-control-feedback"></span>
            </div>
            <div class="form-group has-feedback">
                <input type="password" class="form-control" name="password" placeholder="密码">
                <span class="glyphicon glyphicon-lock form-control-feedback"></span>
            </div>
            <div class="row">
                <div class="col-xs-8">
                    <div class="checkbox icheck">
                        <label>
                            <input type="checkbox"> 记住我
                        </label>
                    </div>
                </div>
                <!-- /.col -->
                <div class="col-xs-4">
                    <button type="submit" class="btn btn-primary btn-block btn-flat">登录</button>
                </div>
                <!-- /.col -->
            </div>
        </form>
        <a href="#">忘记密码</a><br>
    </div>
</div>
<!-- /.login-box-->
<!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
<!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"/>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"/>
<![endif]-->
<!-- jQuery 3 -->
<script src="assets/bower_components/jquery/dist/jquery.min.js"></script>
<!-- Bootstrap 3.3.7 -->
<script src="assets/bower_components/bootstrap/dist/js/bootstrap.min.js"></script>
<!-- iCheck -->
<script src="assets/plugins/iCheck/icheck.min.js"></script>
<script>
    $(function () {
        $('input').iCheck({
            checkboxClass: 'icheckbox_square-blue',
            radioClass: 'iradio_square-blue',
            increaseArea: '20%' /* optional */
        });
    });
</script>
</body>
</html>

　　log4j.properties

log4j.rootLogger=INFO, console, file

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d %p [%c] - %m%n

log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File=logs/log.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.A3.MaxFileSize=1024KB
log4j.appender.A3.MaxBackupIndex=10
log4j.appender.file.layout.ConversionPattern=%d %p [%c] - %m%n

　　CookieUtils

package com.layne.my.shop.common.context.utils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

public final class CookieUtils {

    /**
     * 得到Cookie的值, 不编码
     *
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName) {
        return getCookieValue(request, cookieName, false);
    }

    /**
     * 得到Cookie的值,
     *
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, boolean isDecoder) {
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    if (isDecoder) {
                        retValue = URLDecoder.decode(cookieList[i].getValue(), "UTF-8");
                    } else {
                        retValue = cookieList[i].getValue();
                    }
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return retValue;
    }

    /**
     * 得到Cookie的值,
     *
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, String encodeString) {
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    retValue = URLDecoder.decode(cookieList[i].getValue(), encodeString);
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return retValue;
    }

    /**
     * 设置Cookie的值 不设置生效时间默认浏览器关闭即失效,也不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
                                 String cookieValue) {
        setCookie(request, response, cookieName, cookieValue, -1);
    }

    /**
     * 设置Cookie的值 在指定时间内生效,但不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
                                 String cookieValue, int cookieMaxage) {
        setCookie(request, response, cookieName, cookieValue, cookieMaxage, false);
    }

    /**
     * 设置Cookie的值 不设置生效时间,但编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
                                 String cookieValue, boolean isEncode) {
        setCookie(request, response, cookieName, cookieValue, -1, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
                                 String cookieValue, int cookieMaxage, boolean isEncode) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数(指定编码)
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
                                 String cookieValue, int cookieMaxage, String encodeString) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, encodeString);
    }

    /**
     * 删除Cookie带cookie域名
     */
    public static void deleteCookie(HttpServletRequest request, HttpServletResponse response,
                                    String cookieName) {
        doSetCookie(request, response, cookieName, "", -1, false);
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     *
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
                                          String cookieName, String cookieValue, int cookieMaxage, boolean isEncode) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else if (isEncode) {
                cookieValue = URLEncoder.encode(cookieValue, "utf-8");
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                cookie.setMaxAge(cookieMaxage);
            if (null != request) {// 设置域名的cookie
                String domainName = getDomainName(request);
//                System.out.println(domainName);
                if (!"localhost".equals(domainName)) {
                    cookie.setDomain(domainName);
                }
            }
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     *
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
                                          String cookieName, String cookieValue, int cookieMaxage, String encodeString) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else {
                cookieValue = URLEncoder.encode(cookieValue, encodeString);
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                cookie.setMaxAge(cookieMaxage);
            if (null != request) {// 设置域名的cookie
                String domainName = getDomainName(request);
//                System.out.println(domainName);
                if (!"localhost".equals(domainName)) {
                    cookie.setDomain(domainName);
                }
            }
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 得到cookie的域名
     */
    private static final String getDomainName(HttpServletRequest request) {
        String domainName = null;

        String serverName = request.getRequestURL().toString();
        if (serverName == null || serverName.equals("")) {
            domainName = "";
        } else {
            serverName = serverName.toLowerCase();
            serverName = serverName.substring(7);
            final int end = serverName.indexOf("/");
            serverName = serverName.substring(0, end);
            final String[] domains = serverName.split("\\.");
            int len = domains.length;
            if (len > 3) {
                // www.xxx.com.cn
                domainName = "." + domains[len - 3] + "." + domains[len - 2] + "." + domains[len - 1];
            } else if (len <= 3 && len > 1) {
                // xxx.com or xxx.cn
                domainName = "." + domains[len - 2] + "." + domains[len - 1];
            } else {
                domainName = serverName;
            }
        }

        if (domainName != null && domainName.indexOf(":") > 0) {
            String[] ary = domainName.split("\\:");
            domainName = ary[0];
        }
        return domainName;
    }

}

LoginController

package com.layne.my.shop.web.controller;

import com.layne.my.shop.common.context.SpringContext;
import com.layne.my.shop.common.context.utils.CookieUtils;
import com.layne.my.shop.dao.UserDao;
import com.layne.my.shop.entity.User;
import com.layne.my.shop.service.UserService;
import org.apache.commons.lang3.StringUtils;
import org.springframework.context.ApplicationContext;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class LoginController extends HttpServlet {

    private UserService userService=SpringContext.getBeanExample("userService");

    private static final String COOKIE_NAME_USER_INFO="userInfo";

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         String userInfo = CookieUtils.getCookieValue(req, COOKIE_NAME_USER_INFO);
         if(!StringUtils.isBlank(userInfo)){
             String[] userInfoArray=userInfo.split(":");
             String email=userInfoArray[0];
             String password=userInfoArray[1];
             req.setAttribute("email",email);
             req.setAttribute("password",password);
             req.setAttribute("isRemember",true);
         }
         req.getRequestDispatcher("/login.jsp").forward(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       /* SpringContext springContext=new SpringContext();
        UserService userService = (UserService) springContext.getBean("userService");*/
        boolean isRemember=req.getParameter("isRemember")==null?false:true;
        String email = req.getParameter("email");
        String password = req.getParameter("password");
        User admin=userService.login(email,password);
        if(admin!=null){
            if(isRemember){
                //CookieUtils.setCookie(req,resp,"userInfo",email+":"+password,);
                CookieUtils.setCookie(req,resp,COOKIE_NAME_USER_INFO,String.format("%s:%s",email,password),7*24*60*60);
            }else{
                CookieUtils.deleteCookie(req,resp,COOKIE_NAME_USER_INFO);
            }
            resp.sendRedirect("/main.jsp");
        }else{
            req.setAttribute("message","登录名或密码错误");
            req.getRequestDispatcher("/index.jsp").forward(req,resp);
        }
    }
}