Java秒杀方案

1.课程介绍

1.1. 技术点介绍
前端：Thymeleaf、Bootstrap、JQuery
后端：SpringBoot、MyBatisPlus、Lombok
中间件：RabbitMQ（异步、流量削峰）、Redis（缓存）

1.2. 课程介绍
Java秒杀方案：项目搭建、分布式Session、秒杀功能、压力测试、页面优化、服务优化、接口安全

2.学习目标

通过本课程的学习，主要是学习到怎么应对大并发：怎么使用异步、怎么使用缓存？如何编写优雅的代码？
分布式会话：用户登录、共享Session
功能开发：商品列表、商品详情、秒杀、订单详情
系统压测：JMeter入门、自定义变量、正式压测
页面优化：缓存、静态化分离
服务优化：RabbitMQ消息队列、接口优化、分布式锁
安全优化：隐藏秒杀地址、验证码、接口限流

3.如何设计一个秒杀系统

秒杀，对我们来说，都不是一个陌生的东西。每年的双11，618以及时下流行的直播等等。秒杀然而，这对于我们系统而言是一个巨大的考验。

那么，如何才能更好地理解秒杀系统呢？我觉得作为一个程序员，你首先需要从高纬度出发，从整体上思考问题。在我看来，秒杀其实主要解决两个问题，一个是并发读，一个是并发写。并发读的核心优化理念是尽量减少用户到服务端来“读”数据，或者让他们读更少的数据；并发写的处理原则也一样，它要求我们在数据库层面独立出来一个库，做特殊的处理。另外，我们还要针对秒杀系统做一些保护，针对意料之外的情况设计兜底方案，以防止最坏的情况发生。

其实，秒杀的整体架构可以概括为“稳、准、快”几个关键字。
所谓“稳”，就是整个系统架构要满足高可用，流量符合预期是肯定要稳定，就是超出预期时也同样不能掉链子，你要保证秒杀活动顺利完成，即秒杀商品顺利地卖出去，这个是最基本的前提。
然后就是“准”，就是秒杀10台iPhone，那就只能成交10台，多一台少一台都不行。一旦库存不对，那平台就要承担损失，所以“准”就是要求保证数据的一致性。
最后再看“快”，“快”其实很好理解，它就是说系统的性能要足够高，否则你怎么支撑这么大的流量呢？不光是服务端要做极致的性能优化，而且在整个请求链路上都要做协同的优化，每个地方快一点，整个系统就完美了。

所以从技术角度上看“稳”、“准”、“快”，就对应了我们架构上的高可用、一致性和高性能的要求

• 高性能。秒杀涉及大量的并发读和并发写。因此支持高并发访问这点非常关键。对应的方案比如动静分离方案、热点的发现与隔离，请求的削峰与分层过滤、服务器的极致优化
• 一致性。秒杀中商品减库存的实现方式同样关键。可想而知，有限数量的商品在同一时刻被很多倍的请求同时来减库存，减库存又分为“拍下减库存”“付款减库存”以及预扣等几种，在大并发更新的过程中都要保证数据的准确性，其难度可想而知
• 高可用。现实中总难免出现一些我们考虑不到的情况，所以要保证系统的高可用和正确性，我们还要设计一个PlanB来兜底，以便在最坏情况发生时仍然能够从容应对。

4.项目搭建

4.1. 创建项目

完整目录

添加依赖
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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <!--SpringBoot依赖-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xxxx</groupId>
    <artifactId>seckill</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>seckill</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!--thymeleaf 组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!--web 组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--mybatisplus依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--test 组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--md5 依赖-->
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.8.1</version>
        </dependency>
        <!--validation 组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
        <!--spring data redis 依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <!--commons-pool2 对象池依赖-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

修改配置文件
application.yml

spring:
  # thymeleaf配置
  thymeleaf:
    # 关闭缓存
    cache: false
  # 数据源配置
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/seckill?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
    username: root
    password: root
    hikari:
      # 连接池名
      pool-name: DateHikariCP
      # 最小空闲连接数
      minimum-idle: 5
      # 空闲连接存货最大时间，默认600000(10分钟)
      idle-timeout: 1800000
      # 最大连接数，默认10
      maximum-pool-size: 10
      # 从连接池返回的连接自动提交
      auto-commit: true
      # 连接最大存活时间，0表示永久存活，默认1800000(30分钟)
      max-lifetime: 1800000
      # 连接超时时间，默认30000(30秒)
      connection-timeout: 30000
      # 测试连接是否可用的查询语句
      connection-test-query: SELECT 1

  # redis配置
  redis:
    # 服务器地址
    host: 121.37.15.219
    # 端口
    port: 6379
    # 数据库
    database: 0
    # 超时时间
    timout: 10000ms
    lettuce:
      pool:
        # 最大连接数，默认8
        max-active: 8
        # 最大连接阻塞等待时间，默认-1
        max-wait: 10000ms
        # 最大空闲连接，默认8
        max-idle: 200
        # 最小空闲连接，默认0
        min-idle: 5
    # 密码
    password: kisen

# Mybatis-plus配置
mybatis-plus:
  # 配置Mapper.xml映射文件
  mapper-locations: classpath*:/mapper/*Mapper.xml
  # 配置MyBatis数据返回类型别名(默认别名是类名)
  type-aliases-package: com.xxx.seckill.pojo


# MyBatis SQL打印(方法接口所在的包，不是Mapper.xml所在的包)
logging:
  level:
    com.xxxx.seckill.mapper: debug

测试
DemoController.java

package com.xxxx.seckill.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 测试
 *
 * @ClassName: DemoController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description:
 * @Author: Kisen
 * @Date: 2021/3/1 22:47
 */
@Controller
@RequestMapping("/demo")
public class DemoController {

    /**
     * 测试页面跳转
     * @param model
     * @return
     */
    @RequestMapping("/hello")
    public String hello(Model model){
        model.addAttribute("name", "xxxx");
        return "hello";
    }
}

hello.html

<!doctype html>
<html lang="en"
    xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>测试</title>
</head>
<body>
<p th:text="'hello'+${name}"></p>
</body>
</html>

测试结果

添加公共结果返回对象
RespBeanEnum.java

package com.xxxx.seckill.vo;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.ToString;

/**
 * @ClassName: RespBeanEnum
 * @Title: seckill
 * @Package: com.xxxx.seckill.vo
 * @Description: 公共返回对象枚举
 * @Author: Kisen
 * @Date: 2021/3/4 22:29
 */
@Getter
@ToString
@AllArgsConstructor
public enum RespBeanEnum {
    // 通用
    SUCCES(200, "SUCCES"),
    ERROR(500, "服务端异常"),
    // 登录模块
    LOGIN_ERROR(500210, "用户名或密码不正确"),
    MOBILE_ERROR(500211, "手机号码格式不正确"),
    BIND_ERROR(500212, "参数校验异常");

    private final Integer code;
    private final String message;
}

RespBean.java

package com.xxxx.seckill.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * @ClassName: RespBean
 * @Title: seckill
 * @Package: com.xxxx.seckill.vo
 * @Description: 公共返回对象
 * @Author: Kisen
 * @Date: 2021/3/4 22:29
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
public class RespBean {

    private long code;
    private String message;
    private Object obj;

    /**
     * 成功返回结果
     * @return
     */
    public static RespBean success() {
        return new RespBean(RespBeanEnum.SUCCES.getCode(),RespBeanEnum.SUCCES.getMessage(),null);
    }

    public static RespBean success(Object obj) {
        return new RespBean(RespBeanEnum.SUCCES.getCode(),RespBeanEnum.SUCCES.getMessage(),obj);
    }

    /**
     * 失败返回结果
     * @param respBeanEnum
     * @return
     */
    public static RespBean error(RespBeanEnum respBeanEnum) {
        return new RespBean(respBeanEnum.getCode(),respBeanEnum.getMessage(),null);
    }

    public static RespBean error(RespBeanEnum respBeanEnum, Object obj) {
        return new RespBean(respBeanEnum.getCode(),respBeanEnum.getMessage(),obj);
    }
}

5.分布式会话

5.1. 实现登录功能

5.1.1. 两次MD5加密

用户端：PASS=MD5(明文+固定salt)
服务端：PASS=MD5(用户输入+随机salt)

用户端MD5加密是为了防止用户密码在网络中明文传输，服务端MD5加密是为了提高密码安全性，双重保险。

引入pom.xml

        <!--md5 依赖-->
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.8.1</version>
        </dependency>

编写MD5工具类
MD5Util.java

package com.xxxx.seckill.utils;

import org.apache.commons.codec.digest.DigestUtils;
import org.springframework.stereotype.Component;

/**
 * MD5工具类
 *
 * @ClassName: MD5Util
 * @Title: seckill
 * @Package: com.xxxx.seckill.utils
 * @Description:
 * @Author: Kisen
 * @Date: 2021/3/1 23:24
 */
@Component
public class MD5Util {

    private static final String salt = "1a2b3c4d";

    public static String md5(String src){
        return DigestUtils.md5Hex(src);
    }

    public static String inputPassToFormPass(String inputPass){
        String str = "" + salt.charAt(0) + salt.charAt(2) + inputPass + salt.charAt(5) + salt.charAt(4);
        return md5(str);
    }

    public static String formPassToDBPass(String formPass, String salt){
        String str = "" + salt.charAt(0) + salt.charAt(2) + formPass + salt.charAt(5) + salt.charAt(4);
        return md5(str);
    }

    public static String inputPassToDBPass(String inputPass, String salt){
        String formPass = inputPassToFormPass(inputPass);
        String dbPass = formPassToDBPass(formPass, salt);
        return dbPass;
    }

    public static void main(String[] args) {
        // ce21b747de5af71ab5c2e20ff0a60eea
        System.out.println(inputPassToFormPass("123456"));
        System.out.println(formPassToDBPass("d3b1294a61a07da9b49b6e22b2cbd7f9", "1a2b3c4d"));
        System.out.println(inputPassToDBPass("123456", "1a2b3c4d"));
    }
}

5.1.2. 登录功能实现

逆向工程

首先需要通过逆向工程t_user表生产对应POJO、Mapper、Service、ServiceImpl、Controller等类，项目中使用了MyBatisPlus，所以逆向工程也是用了MyBatisPlus提供的AutoGenerator，代码如下。具体可去官网查看

CodeGenerator.java

package com.xxxx.generator;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

/**
 * @ClassName: CodeGenerator
 * @Title: generator
 * @Package: com.xxxx.generator
 * @Description:
 * @Author: Kisen
 * @Date: 2021/3/4 21:52
 */
public class CodeGenerator {

    /**
     * <p>
     * 读取控制台内容
     * </p>
     */
    public static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder help = new StringBuilder();
        help.append("请输入" + tip + "：");
        System.out.println(help.toString());
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (StringUtils.isNotBlank(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("请输入正确的" + tip + "！");
    }

    public static void main(String[] args) {
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();

        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        gc.setOutputDir(projectPath + "/src/main/java");
        //作者
        gc.setAuthor("kisen");
        //打开输出目录
        gc.setOpen(false);
        //xml开启BaseResultMap
        gc.setBaseResultMap(true);
        //xml开启BaseColumnList
        gc.setBaseColumnList(true);
        //日期格式，采用Date
        gc.setDateType(DateType.ONLY_DATE);
        // gc.setSwagger2(true); 实体属性 Swagger2 注解
        mpg.setGlobalConfig(gc);

        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://localhost:3306/seckill?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai");
        // dsc.setSchemaName("public");
        dsc.setDriverName("com.mysql.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("root");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        pc.setParent("com.xxxx.seckill")
                .setEntity("pojo")
                .setMapper("mapper")
                .setService("service")
                .setServiceImpl("service.impl")
                .setController("controller");
        mpg.setPackageInfo(pc);

        // 自定义配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };

        // 如果模板引擎是 freemarker
        String templatePath = "/templates/mapper.xml.ftl";
        // 如果模板引擎是 velocity
        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置
        List<FileOutConfig> focList = new ArrayList<>();
        // 自定义配置会被优先输出
        focList.add(new FileOutConfig(templatePath) {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！
                return projectPath + "/src/main/resources/mapper/" + "/" + tableInfo.getEntityName() + "Mapper"
                        + StringPool.DOT_XML;
            }
        });
        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);

        // 配置模板
        TemplateConfig templateConfig = new TemplateConfig()
                .setEntity("templates/entity2.java")
                .setMapper("templates/mapper2.java")
                .setService("templates/service2.java")
                .setServiceImpl("templates/serviceImpl2.java")
                .setController("templates/controller2.java");

        templateConfig.setXml(null);
        mpg.setTemplate(templateConfig);

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        //数据库表映射到实体的命名策略
        strategy.setNaming(NamingStrategy.underline_to_camel);
        //数据库表字段映射到实体的命名策略
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        //lombok模型
        strategy.setEntityLombokModel(true);
        //生成@RestController控制器
        // strategy.setRestControllerStyle(true);
        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));
        strategy.setControllerMappingHyphenStyle(true);
        //表前缀
        strategy.setTablePrefix("t_");
        mpg.setStrategy(strategy);
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
    }
}

ValidatorUtil.java

package com.xxxx.seckill.utils;

import org.apache.commons.lang3.StringUtils;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @ClassName: ValidatorUtil
 * @Title: seckill
 * @Package: com.xxxx.seckill.utils
 * @Description: 手机号码校验
 * @Author: Kisen
 * @Date: 2021/3/6 15:31
 */
public class ValidatorUtil {

    private static final Pattern mobile_pattern = Pattern.compile("[1]([3-9])[0-9]{9}$");

    public static boolean isMobile(String mobile) {
        if (StringUtils.isEmpty(mobile)) {
            return false;
        }
        Matcher matcher = mobile_pattern.matcher(mobile);
        return matcher.matches();
    }
}

LoginController.java

package com.xxxx.seckill.controller;

import com.xxxx.seckill.service.IUserService;
import com.xxxx.seckill.vo.LoginVo;
import com.xxxx.seckill.vo.RespBean;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.validation.Valid;

/**
 * @ClassName: LoginController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description:
 * @Author: Kisen
 * @Date: 2021/3/4 22:17
 */
@Controller
@RequestMapping("/login")
@Slf4j
public class LoginController {

    @Autowired
    private IUserService userService;

    /**
     * 跳转登录页面
     * @return
     */
    @RequestMapping("/toLogin")
    public String toLogin() {
        return "login";
    }

    /**
     * 登录功能
     * @param loginVo
     * @return
     */
    @RequestMapping("/doLogin")
    @ResponseBody
    public RespBean doLogin(@Valid LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        return userService.doLogin(loginVo, request, response);
    }
}

IUserService.java

package com.xxxx.seckill.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.vo.LoginVo;
import com.xxxx.seckill.vo.RespBean;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author kisen
 * @since 2021-03-04
 */
public interface IUserService extends IService<User> {

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response);

    /**
     * 根据cookie获取用户
     * @param userTicket
     * @return
     */
    User getUserByCookie(String userTicket, HttpServletRequest request, HttpServletResponse response);

}

UserServiceImpl.java

package com.xxxx.seckill.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.xxxx.seckill.exception.GlobalException;
import com.xxxx.seckill.mapper.UserMapper;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import com.xxxx.seckill.utils.CookieUtil;
import com.xxxx.seckill.utils.MD5Util;
import com.xxxx.seckill.utils.UUIDUtil;
import com.xxxx.seckill.vo.LoginVo;
import com.xxxx.seckill.vo.RespBean;
import com.xxxx.seckill.vo.RespBeanEnum;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author kisen
 * @since 2021-03-04
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

    @Autowired
    private UserMapper userMapper;
    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    @Override
    public RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        String mobile = loginVo.getMobile();
        String password = loginVo.getPassword();
        /*// 参数校验
        if (StringUtils.isEmpty(mobile) || StringUtils.isEmpty(password)) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        if (!ValidatorUtil.isMobile(mobile)) {
            return RespBean.error(RespBeanEnum.MOBILE_ERROR);
        }*/
        // 根据手机号获取用户
        User user = userMapper.selectById(mobile);
        if (null == user) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 判断密码是否正确
        if (!MD5Util.formPassToDBPass(password, user.getSalt()).equals(user.getPassword())) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 生成cookie
        String ticket = UUIDUtil.uuid();
        // 将用户信息存入redis中
        redisTemplate.opsForValue().set("user:" + ticket, user);
//        request.getSession().setAttribute(ticket, user);
        CookieUtil.setCookie(request, response, "userTicket", ticket);
        return RespBean.success();
    }

    /**
     * 根据cookie获取用户
     * @param userTicket
     * @return
     */
    @Override
    public User getUserByCookie(String userTicket, HttpServletRequest request, HttpServletResponse response) {
        if (StringUtils.isEmpty(userTicket)) {
            return null;
        }
        User user = (User) redisTemplate.opsForValue().get("user:" + userTicket);
        if (user != null) {
            CookieUtil.setCookie(request, response, "userTicket", userTicket);
        }
        return user;
    }
}

login.html

<!DOCTYPE html>
<html lang="en"
      xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>登录</title>
    <!-- jquery -->
    <script type="text/javascript" th:src="@{/js/jquery.min.js}"></script>
    <!-- bootstrap -->
    <link rel="stylesheet" type="text/css" th:href="@{/bootstrap/css/bootstrap.min.css}"/>
    <script type="text/javascript" th:src="@{/bootstrap/js/bootstrap.min.js}"></script>
    <!-- jquery-validator -->
    <script type="text/javascript" th:src="@{/jquery-validation/jquery.validate.min.js}"></script>
    <script type="text/javascript" th:src="@{/jquery-validation/localization/messages_zh.min.js}"></script>
    <!-- layer -->
    <script type="text/javascript" th:src="@{/layer/layer.js}"></script>
    <!-- md5.js -->
    <script type="text/javascript" th:src="@{/js/md5.min.js}"></script>
    <!-- common.js -->
    <script type="text/javascript" th:src="@{/js/common.js}"></script>
</head>
<body>
<form name="loginForm" id="loginForm" method="post" style="width:50%; margin:0 auto">

    <h2 style="text-align:center; margin-bottom: 20px">用户登录</h2>

    <div class="form-group">
        <div class="row">
            <label class="form-label col-md-4">请输入手机号码</label>
            <div class="col-md-5">
                <input id="mobile" name="mobile" class="form-control" type="text" placeholder="手机号码" required="true"
                       minlength="11" maxlength="11"/>
            </div>
            <div class="col-md-1">
            </div>
        </div>
    </div>

    <div class="form-group">
        <div class="row">
            <label class="form-label col-md-4">请输入密码</label>
            <div class="col-md-5">
                <input id="password" name="password" class="form-control" type="password" placeholder="密码"
                       required="true" minlength="6" maxlength="16"/>
            </div>
        </div>
    </div>

    <div class="row">
        <div class="col-md-5">
            <button class="btn btn-primary btn-block" type="reset" onclick="reset()">重置</button>
        </div>
        <div class="col-md-5">
            <button class="btn btn-primary btn-block" type="submit" onclick="login()">登录</button>
        </div>
    </div>
</form>
</body>
<script>
    function login() {
        $("#loginForm").validate({
            submitHandler: function (form) {
                doLogin();
            }
        });
    }

    function doLogin() {
        g_showLoading();

        var inputPass = $("#password").val();
        var salt = g_passsword_salt;
        var str = "" + salt.charAt(0) + salt.charAt(2) + inputPass + salt.charAt(5) + salt.charAt(4);
        var password = md5(str);

        $.ajax({
            url: "/login/doLogin",
            type: "POST",
            data: {
                mobile: $("#mobile").val(),
                password: password
            },
            success: function (data) {
                layer.closeAll();
                if (data.code == 200) {
                    layer.msg("成功");
                    window.location.href="/goods/toList";
                } else {
                    layer.msg(data.message);
                }
            },
            error: function () {
                layer.closeAll();
            }
        });
    }
</script>
</html>

测试

手机号码格式不正确

手机号码或密码不正确

正确登录

5.2. 参数校验

每个类都写大量的健壮性判断过于麻烦，我们可以使用validation简化我们的代码

添加依赖
pom.xml

        <!--validation 组件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

自定义手机号码验证规则
IsMobileValidator.java

package com.xxxx.seckill.vo;

import com.xxxx.seckill.utils.ValidatorUtil;
import com.xxxx.seckill.validator.IsMobile;
import org.apache.commons.lang3.StringUtils;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

/**
 * @ClassName: IsMobileValidator
 * @Title: seckill
 * @Package: com.xxxx.seckill.vo
 * @Description: 手机号码校验规则
 * @Author: Kisen
 * @Date: 2021/3/6 16:48
 */
public class IsMobileValidator implements ConstraintValidator<IsMobile, String> {

    private boolean required = false;

    @Override
    public void initialize(IsMobile constraintAnnotation) {
        required = constraintAnnotation.required();
    }

    @Override
    public boolean isValid(String s, ConstraintValidatorContext constraintValidatorContext) {
        if (required) {
            return ValidatorUtil.isMobile(s);
        } else {
            if (StringUtils.isEmpty(s)) {
                return true;
            } else {
                return ValidatorUtil.isMobile(s);
            }
        }
    }
}

自定义注解
IsMobile.java

package com.xxxx.seckill.validator;

import com.xxxx.seckill.vo.IsMobileValidator;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.*;

/**
 * @ClassName: IsMobile
 * @Title: seckill
 * @Package: com.xxxx.seckill.validator
 * @Description: 验证手机号
 * @Author: Kisen
 * @Date: 2021/3/6 16:46
 */
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.TYPE_USE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(
        validatedBy = {IsMobileValidator.class}
)
public @interface IsMobile {

    boolean required() default true;

    String message() default "手机号码格式错误";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
}

修改LoginVo
LoginVo.java

package com.xxxx.seckill.vo;

import com.xxxx.seckill.validator.IsMobile;
import lombok.Data;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.NotNull;

/**
 * @ClassName: LoginVo
 * @Title: seckill
 * @Package: com.xxxx.seckill.vo
 * @Description: 登录参数
 * @Author: Kisen
 * @Date: 2021/3/6 15:14
 */
@Data
public class LoginVo {

    @NotNull
    @IsMobile
    private String mobile;

    @NotNull
    @Length(min = 32)
    private String password;
}

其他修改

LoginController.java
入参添加@Valid

    /**
     * 登录功能
     * @param loginVo
     * @return
     */
    @RequestMapping("/doLogin")
    @ResponseBody
    public RespBean doLogin(@Valid LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        return userService.doLogin(loginVo, request, response);
    }

UserServiceImpl.java
注释掉之前的健壮性判断即可

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    @Override
    public RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        String mobile = loginVo.getMobile();
        String password = loginVo.getPassword();
        /*// 参数校验
        if (StringUtils.isEmpty(mobile) || StringUtils.isEmpty(password)) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        if (!ValidatorUtil.isMobile(mobile)) {
            return RespBean.error(RespBeanEnum.MOBILE_ERROR);
        }*/
        // 根据手机号获取用户
        User user = userMapper.selectById(mobile);
        if (null == user) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        // 判断密码是否正确
        if (!MD5Util.formPassToDBPass(password, user.getSalt()).equals(user.getPassword())) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        return RespBean.success();
    }

测试

5.3. 异常处理

系统中异常包括：编译时异常和运行时异常RuntimeException，前者通过捕获异常从而获得异常信息，后者主要通过规范代码开发、测试通过手段减少运行时异常的发生。在开发中，不管是dao层、service层还是controller层，都有可能抛出异常，在SpringMVC中，能将所有类型的异常处理从各处理过程解耦处来，既保证了相关处理过程的功能较单一，也实现了异常信息的统一处理和维护。SpringBoot全局异常处理方式主要两种：
使用@ControllerAdvice和@ExceptionHandler注解。
使用ErrorController类来实现
区别：
@ControllerAdvice方式只能处理控制器抛出的异常。此时请求已经进入控制器中。
ErrorController类方式可以处理所有的异常，包括未进入控制器的错误，比如404，401等错误
如果应用中两者共同存在，则@ControllerAdvice方式处理控制器抛出的异常，ErrorController类方式处理未进入控制器的异常。
@ControllerAdvice方式可以定义多个拦截方式，拦截不同的异常类，并且可以获取抛出的异常信息，自由度更大。

GlobalException.java

package com.xxxx.seckill.exception;

import com.xxxx.seckill.vo.RespBeanEnum;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * @ClassName: GlobalException
 * @Title: seckill
 * @Package: com.xxxx.seckill.exception
 * @Description: 全局异常
 * @Author: Kisen
 * @Date: 2021/3/7 12:59
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
public class GlobalException extends RuntimeException {
    private RespBeanEnum respBeanEnum;
}

GlobalExceptionHandler.java

package com.xxxx.seckill.exception;

import com.xxxx.seckill.vo.RespBean;
import com.xxxx.seckill.vo.RespBeanEnum;
import org.springframework.validation.BindException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

/**
 * @ClassName: GlobalExceptionHandler
 * @Title: seckill
 * @Package: com.xxxx.seckill.exception
 * @Description: 全局异常处理
 * @Author: Kisen
 * @Date: 2021/3/7 13:01
 */
@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    public RespBean ExceptionHandler(Exception e) {
        if (e instanceof GlobalException) {
            GlobalException ex = (GlobalException) e;
            return RespBean.error(ex.getRespBeanEnum());
        } else if (e instanceof BindException) {
            BindException ex = (BindException) e;
            RespBean respBean = RespBean.error(RespBeanEnum.BIND_ERROR);
            respBean.setMessage("参数校验异常：" + ex.getBindingResult().getAllErrors().get(0).getDefaultMessage());
            return respBean;
        }
        return RespBean.error(RespBeanEnum.ERROR);
    }
}

修改之前代码
直接返回RespBean改为直接抛GlobalException异常

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    @Override
    public RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        String mobile = loginVo.getMobile();
        String password = loginVo.getPassword();
        /*// 参数校验
        if (StringUtils.isEmpty(mobile) || StringUtils.isEmpty(password)) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        if (!ValidatorUtil.isMobile(mobile)) {
            return RespBean.error(RespBeanEnum.MOBILE_ERROR);
        }*/
        // 根据手机号获取用户
        User user = userMapper.selectById(mobile);
        if (null == user) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 判断密码是否正确
        if (!MD5Util.formPassToDBPass(password, user.getSalt()).equals(user.getPassword())) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        return RespBean.success();
    }

测试

6.分布式Session

6.1. 完善登录功能

使用cookie+session记录用户信息

准备工具类
CookieUtil.java

package com.xxxx.seckill.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;

/**
 * @ClassName: CookieUtil
 * @Title: seckill
 * @Package: com.xxxx.seckill.utils
 * @Description: Cookie工具类
 * @Author: Kisen
 * @Date: 2021/3/7 13:48
 */
public class CookieUtil {

    /**
     * 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
     * @param isDecoder
     * @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
     * @param encodeString
     * @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生效，也不编码
     * @param request
     * @param response
     * @param cookieName
     * @param cookieValue
     */
    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
     * @param request
     * @param response
     * @param cookieName
     * @param cookieValue
     * @param cookieMaxage
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response,
                                 String cookieName, String cookieValue, int cookieMaxage) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, false);
    }

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

    /**
     * 设置Cookie的值 在指定时间内生效，编码参数
     * @param request
     * @param response
     * @param cookieName
     * @param cookieValue
     * @param cookieMaxage
     * @param isEncode
     */
    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)
     * @param request
     * @param response
     * @param cookieName
     * @param cookieValue
     * @param cookieMaxage
     * @param encodeString
     */
    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
     * @param request
     * @param response
     * @param cookieName
     */
    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 request
     * @param response
     * @param cookieName
     * @param cookieValue
     * @param cookieMaxage
     * @param isEncode
     */
    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 request
     * @param response
     * @param cookieName
     * @param cookieValue
     * @param cookieMaxage
     * @param encodeString
     */
    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
     * @param request
     * @return
     */
    private static final String getDomainName(HttpServletRequest request) {
        String domainName = null;
        // 通过request对象获取访问的url地址
        String serverName = request.getRequestURL().toString();
        if (serverName == null || serverName.equals("")) {
            domainName = "";
        } else {
            // 将url地址转换为小写
            serverName = serverName.toLowerCase();
            // 如果url地址是以http://开头   将http://截取
            if (serverName.startsWith("http:/")) {
                serverName = serverName.substring(7);
            }
            int end = serverName.length();
            // 判断url地址是否包含"/"
            if (serverName.contains("/")) {
                // 得到第一个"/"出现的位置
                end = serverName.indexOf("/");
            }

            // 截取
            serverName = serverName.substring(0, end);
            // 根据"."进行分割
            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[] array = domainName.split("\\:");
            domainName = array[0];
        }
        return domainName;
    }
}

UUIDUtil.java

package com.xxxx.seckill.utils;

import java.util.UUID;

/**
 * @ClassName: UUIDUtil
 * @Title: seckill
 * @Package: com.xxxx.seckill.utils
 * @Description: UUID工具类
 * @Author: Kisen
 * @Date: 2021/3/7 13:31
 */
public class UUIDUtil {

    public static String uuid() {
        return UUID.randomUUID().toString().replace("-", "");
    }
}

UserServiceImpl.java

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    @Override
    public RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        String mobile = loginVo.getMobile();
        String password = loginVo.getPassword();
        /*// 参数校验
        if (StringUtils.isEmpty(mobile) || StringUtils.isEmpty(password)) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        if (!ValidatorUtil.isMobile(mobile)) {
            return RespBean.error(RespBeanEnum.MOBILE_ERROR);
        }*/
        // 根据手机号获取用户
        User user = userMapper.selectById(mobile);
        if (null == user) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 判断密码是否正确
        if (!MD5Util.formPassToDBPass(password, user.getSalt()).equals(user.getPassword())) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
         // 生成cookie
        String ticket = UUIDUtil.uuid();
        request.getSession().setAttribute(ticket, user);
        CookieUtil.setCookie(request, response, "userTicket", ticket);
        return RespBean.success();
    }

LoginController.java

    /**
     * 登录功能
     * @param loginVo
     * @return
     */
    @RequestMapping("/doLogin")
    @ResponseBody
    public RespBean doLogin(@Valid LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        return userService.doLogin(loginVo, request, response);
    }

GoodsController.java

package com.xxxx.seckill.controller;

import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @ClassName: GoodsController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description: 商品
 * @Author: Kisen
 * @Date: 2021/3/7 14:47
 */
@Controller
@RequestMapping("/goods")
@Slf4j
public class GoodsController {

    @Autowired
    private IUserService userService;

    @RequestMapping("/toList")
    public String toList(Model model, User user) {
        if (StringUtils.isEmpty(ticket)) {
            return "login";
        }
        User user = (User) session.getAttribute(ticket);
        if (null == user) {
            return "login";
        }
        model.addAttribute("user", user);
        return "goodsList";
    }

}

login.html

        $.ajax({
            url: "/login/doLogin",
            type: "POST",
            data: {
                mobile: $("#mobile").val(),
                password: password
            },
            success: function (data) {
                layer.closeAll();
                if (data.code == 200) {
                    layer.msg("成功");
                    window.location.href="/goods/toList";
                } else {
                    layer.msg(data.message);
                }
            },
            error: function () {
                layer.closeAll();
            }
        });

goodsList.html

<!DOCTYPE html>
<html lang="en"
      xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>商品列表</title>
</head>
<body>
<p th:text="'Hello:'+${user.nickname}"></p>
</body>
</html>

测试

7.分布式Session问题

之前的代码在我们之后一台应用系统，所有操作都在一台Tomcat上，没有什么问题。当我们部署多台系统，配合Nginx的时候会出现用户登录的问题。

原因
由于Nginx使用默认负载均衡策略（轮询），请求将会按照时间顺序逐一分发到后端应用上。
也就是说刚开始我们在Tomcat1登录之后，用户信息放在Tomcat1的Session里。过来一会，请求又被Nginx分发到了Tomcat2上，这时Tomcat2上Session里还没有用户信息，于是又要登录。

解决方案：
    Session复制
        优点：无需修改代码，只需要修改Tomcat配置
        缺点：
            Session同步传输占用内网带宽
            多台Tomcat同步性能指数级下降
            Session占用内存，无法有效水平扩展
    前端存储
        优点：不占用服务端内存
        缺点：
            存在安全风险
            数据大小受cookie限制
            占用外网带宽
    Session粘滞
        优点：
            无需修改代码
            服务端可以水平扩展
        缺点：
            增加新机器，会重新Hash，导致重新登录
            应用重启，需要重新登录
    后端集中存储
        优点：
            安全
            容易水平扩展
        缺点：
            增加复杂度
            需要修改代码

8.Redis安装

下载地址
http://redis.io/

将下载好的安装包上传至服务器

解压
tar zxvf redis-5.0.5.tar.gz
安装依赖
yum -y install gcc-c++ autoconf automake
预编译

# 切换至解压目录
cd redis-5.0.5/
# 预编译
make

安装

# 创建安装目录
mkdir -p /usr/local/redis
# 安装
make PREFIX=/usr/local/redis/ install

修改配置文件

# 复制redis.conf至安装路径下
cp redis.conf /usr/local/redis/
# 修改配置文件
vim /usr/local/redis/redis.conf

修改内容如下

#bind 127.0.0.1
#关闭保护模式
protected-mode no
#后台启动
daemonize yes
#添加访问认证
requirepass root

启动redis
./redis-server redis.conf

9.Redis实现分布式Session

9.1. 方法一：使用SpringSession实现

添加依赖
pom.xml

        <!--spring data redis 依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <!--commons-pool2 对象池依赖-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>
        <!--spring-session 依赖-->
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-data-redis</artifactId>
        </dependency>

添加配置
application.yml

  # redis配置
  redis:
    # 服务器地址
    host: 121.37.15.219
    # 端口
    port: 6379
    # 数据库
    database: 0
    # 超时时间
    timout: 10000ms
    lettuce:
      pool:
        # 最大连接数，默认8
        max-active: 8
        # 最大连接阻塞等待时间，默认-1
        max-wait: 10000ms
        # 最大空闲连接，默认8
        max-idle: 200
        # 最小空闲连接，默认0
        min-idle: 5
    # 密码
    password: kisen

测试
其余代码暂时不动，重新登录测试。会发现session已经存储在Redis上

9.2. 方法二：将用户信息存入Redis

依赖

        <!--spring data redis 依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <!--commons-pool2 对象池依赖-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>

添加配置

spring:
  # redis配置
  redis:
    # 服务器地址
    host: 121.37.15.219
    # 端口
    port: 6379
    # 数据库
    database: 0
    # 超时时间
    timout: 10000ms
    lettuce:
      pool:
        # 最大连接数，默认8
        max-active: 8
        # 最大连接阻塞等待时间，默认-1
        max-wait: 10000ms
        # 最大空闲连接，默认8
        max-idle: 200
        # 最小空闲连接，默认0
        min-idle: 5
    # 密码
    password: kisen

RedisConfig.java

package com.xxxx.seckill.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * @ClassName: RedisConfig
 * @Title: seckill
 * @Package: com.xxxx.seckill.config
 * @Description: Redis配置类
 * @Author: Kisen
 * @Date: 2021/3/9 0:29
 */
@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        // key序列化
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        // value序列化
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        // hash类型 key序列化
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        // hash类型 value序列化
        redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        // 注入连接工厂
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        return redisTemplate;
    }
}

修改之前代码
IUserService.java

    /**
     * 根据cookie获取用户
     * @param userTicket
     * @return
     */
    User getUserByCookie(String userTicket, HttpServletRequest request, HttpServletResponse response);

UserServiceImpl.java

package com.xxxx.seckill.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.xxxx.seckill.exception.GlobalException;
import com.xxxx.seckill.mapper.UserMapper;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import com.xxxx.seckill.utils.CookieUtil;
import com.xxxx.seckill.utils.MD5Util;
import com.xxxx.seckill.utils.UUIDUtil;
import com.xxxx.seckill.vo.LoginVo;
import com.xxxx.seckill.vo.RespBean;
import com.xxxx.seckill.vo.RespBeanEnum;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author kisen
 * @since 2021-03-04
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

    @Autowired
    private UserMapper userMapper;
    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 登录
     * @param loginVo
     * @param request
     * @param response
     * @return
     */
    @Override
    public RespBean doLogin(LoginVo loginVo, HttpServletRequest request, HttpServletResponse response) {
        String mobile = loginVo.getMobile();
        String password = loginVo.getPassword();
        /*// 参数校验
        if (StringUtils.isEmpty(mobile) || StringUtils.isEmpty(password)) {
            return RespBean.error(RespBeanEnum.LOGIN_ERROR);
        }
        if (!ValidatorUtil.isMobile(mobile)) {
            return RespBean.error(RespBeanEnum.MOBILE_ERROR);
        }*/
        // 根据手机号获取用户
        User user = userMapper.selectById(mobile);
        if (null == user) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 判断密码是否正确
        if (!MD5Util.formPassToDBPass(password, user.getSalt()).equals(user.getPassword())) {
            throw new GlobalException(RespBeanEnum.LOGIN_ERROR);
        }
        // 生成cookie
        String ticket = UUIDUtil.uuid();
        // 将用户信息存入redis中
        redisTemplate.opsForValue().set("user:" + ticket, user);
//        request.getSession().setAttribute(ticket, user);
        CookieUtil.setCookie(request, response, "userTicket", ticket);
        return RespBean.success();
    }

    /**
     * 根据cookie获取用户
     * @param userTicket
     * @return
     */
    @Override
    public User getUserByCookie(String userTicket, HttpServletRequest request, HttpServletResponse response) {
        if (StringUtils.isEmpty(userTicket)) {
            return null;
        }
        User user = (User) redisTemplate.opsForValue().get("user:" + userTicket);
        if (user != null) {
            CookieUtil.setCookie(request, response, "userTicket", userTicket);
        }
        return user;
    }
}

GoodsController.java

package com.xxxx.seckill.controller;

import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @ClassName: GoodsController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description: 商品
 * @Author: Kisen
 * @Date: 2021/3/7 14:47
 */
@Controller
@RequestMapping("/goods")
@Slf4j
public class GoodsController {

    @Autowired
    private IUserService userService;

    @RequestMapping("/toList")
    public String toList(Model model, HttpServletRequest request, HttpServletResponse response, @CookieValue("userTicket") String ticket) {
        if (StringUtils.isEmpty(ticket)) {
            return "login";
        }
//        User user = (User) session.getAttribute(ticket);
        User user = userService.getUserByCookie(ticket, request, response);
        if (null == user) {
            return "login";
        }
        model.addAttribute("user", user);
        return "goodsList";
    }

}

测试

Web全局校验登录功能

UserArgumentResolver.java

package com.xxxx.seckill.config;

import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import com.xxxx.seckill.utils.CookieUtil;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.MethodParameter;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @ClassName: UserArgumentResolver
 * @Title: seckill
 * @Package: com.xxxx.seckill.config
 * @Description: 自定义用户参数
 * @Author: Kisen
 * @Date: 2021/3/9 22:39
 */
@Component
public class UserArgumentResolver implements HandlerMethodArgumentResolver {

    @Autowired
    private IUserService userService;

    @Override
    public boolean supportsParameter(MethodParameter methodParameter) {
        Class<?> clazz = methodParameter.getParameterType();
        return clazz == User.class;
    }

    @Override
    public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
        HttpServletRequest request = nativeWebRequest.getNativeRequest(HttpServletRequest.class);
        HttpServletResponse response = nativeWebRequest.getNativeResponse(HttpServletResponse.class);
        String ticket = CookieUtil.getCookieValue(request, "userTicket");
        if (StringUtils.isEmpty(ticket)) {
            return null;
        }
        return userService.getUserByCookie(ticket, request, response);
    }
}

WebConfig.java

package com.xxxx.seckill.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.List;

/**
 * @ClassName: WebConfig
 * @Title: seckill
 * @Package: com.xxxx.seckill.config
 * @Description: MVC配置类
 * @Author: Kisen
 * @Date: 2021/3/9 22:37
 */
@Configuration
//@EnableWebMvc //添加该注解，则是完全控制MVC
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private UserArgumentResolver userArgumentResolver;

    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(userArgumentResolver);
    }
}

GoodsController.java

package com.xxxx.seckill.controller;

import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IUserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @ClassName: GoodsController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description: 商品
 * @Author: Kisen
 * @Date: 2021/3/7 14:47
 */
@Controller
@RequestMapping("/goods")
@Slf4j
public class GoodsController {

    @Autowired
    private IUserService userService;

    @RequestMapping("/toList")
    public String toList(Model model, User user) {
//        if (StringUtils.isEmpty(ticket)) {
//            return "login";
//        }
////        User user = (User) session.getAttribute(ticket);
//        User user = userService.getUserByCookie(ticket, request, response);
//        if (null == user) {
//            return "login";
//        }
        model.addAttribute("user", user);
        return "goodsList";
    }

}

10.秒杀功能

10.1. 商品列表页

用逆向工程生成所需的所有类

GoodsVo
同时查询商品表和秒杀商品表的返回对象

 package com.xxxx.seckill.vo;

import com.xxxx.seckill.pojo.Goods;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.math.BigDecimal;
import java.util.Date;

/**
 * @ClassName: GoodsVo
 * @Title: seckill
 * @Package: com.xxxx.seckill.vo
 * @Description: 商品返回对象
 * @Author: Kisen
 * @Date: 2021/3/14 16:09
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class GoodsVo extends Goods {
    private BigDecimal seckillPrice;
    private Integer stockCount;
    private Date startDate;
    private Date endDate;
}

GoodsMapper.java

package com.xxxx.seckill.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.xxxx.seckill.pojo.Goods;
import com.xxxx.seckill.vo.GoodsVo;

import java.util.List;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author kisen
 * @since 2021-03-14
 */
public interface GoodsMapper extends BaseMapper<Goods> {

    /**
     * 获取商品列表
     * @return
     */
    List<GoodsVo> findGoodsVo();
}

GoodsMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xxxx.seckill.mapper.GoodsMapper">

    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="com.xxxx.seckill.pojo.Goods">
        <id column="id" property="id" />
        <result column="goods_name" property="goodsName" />
        <result column="goods_title" property="goodsTitle" />
        <result column="goods_img" property="goodsImg" />
        <result column="goods_detail" property="goodsDetail" />
        <result column="goods_price" property="goodsPrice" />
        <result column="goods_stock" property="goodsStock" />
    </resultMap>

    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
        id, goods_name, goods_title, goods_img, goods_detail, goods_price, goods_stock
    </sql>

    <!-- 获取商品列表 -->
    <select id="findGoodsVo" resultType="com.xxxx.seckill.vo.GoodsVo">
        SELECT
            g.id,
            g.goods_name,
            g.goods_title,
            g.goods_img,
            g.goods_detail,
            g.goods_price,
            g.goods_stock,
            sg.seckill_price,
            sg.stock_count,
            sg.start_date,
            sg.end_date
        FROM t_goods g
        LEFT JOIN t_seckill_goods sg ON g.id=sg.goods_id
    </select>
</mapper>

GoodsService
IGoodService.java

package com.xxxx.seckill.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.xxxx.seckill.pojo.Goods;
import com.xxxx.seckill.vo.GoodsVo;

import java.util.List;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author kisen
 * @since 2021-03-14
 */
public interface IGoodsService extends IService<Goods> {

    /**
     * 获取商品列表
     * @return
     */
    List<GoodsVo> findGoodsVo();
}

GoodsServiceImpl.java

package com.xxxx.seckill.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.xxxx.seckill.mapper.GoodsMapper;
import com.xxxx.seckill.pojo.Goods;
import com.xxxx.seckill.service.IGoodsService;
import com.xxxx.seckill.vo.GoodsVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author kisen
 * @since 2021-03-14
 */
@Service
public class GoodsServiceImpl extends ServiceImpl<GoodsMapper, Goods> implements IGoodsService {

    @Autowired
    private GoodsMapper goodsMapper;

    /**
     * 获取商品列表
     * @return
     */
    @Override
    public List<GoodsVo> findGoodsVo() {
        return goodsMapper.findGoodsVo();
    }
}

GoodsController

package com.xxxx.seckill.controller;

import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IGoodsService;
import com.xxxx.seckill.service.IUserService;
import com.xxxx.seckill.vo.GoodsVo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.Date;

/**
 * @ClassName: GoodsController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description: 商品
 * @Author: Kisen
 * @Date: 2021/3/7 14:47
 */
@Controller
@RequestMapping("/goods")
@Slf4j
public class GoodsController {

    @Autowired
    private IUserService userService;
    @Autowired
    private IGoodsService goodsService;

    /**
     * 跳转商品列表页
     * @param model
     * @param user
     * @return
     */
    @RequestMapping("/toList")
    public String toList(Model model, User user) {
        model.addAttribute("user", user);
        model.addAttribute("goodsList", goodsService.findGoodsVo());
        return "goodsList";
    }

}

MvcConfig

package com.xxxx.seckill.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.List;

/**
 * @ClassName: WebConfig
 * @Title: seckill
 * @Package: com.xxxx.seckill.config
 * @Description: MVC配置类
 * @Author: Kisen
 * @Date: 2021/3/9 22:37
 */
@Configuration
//@EnableWebMvc //添加该注解，则是完全控制MVC
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private UserArgumentResolver userArgumentResolver;

    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(userArgumentResolver);
    }
//
//    @Override
//    public void addResourceHandlers(ResourceHandlerRegistry registry) {
//        registry.addResourceHandler("/**").addResourceLocations("classpath:/static/");
//    }
}

goodsList.html

<!DOCTYPE html>
<html lang="en"
      xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>商品列表</title>
    <!-- jquery -->
    <script type="text/javascript" th:src="@{/js/jquery.min.js}"></script>
    <!-- bootstrap -->
    <link rel="stylesheet" type="text/css" th:href="@{/bootstrap/css/bootstrap.min.css}"/>
    <script type="text/javascript" th:src="@{/bootstrap/js/bootstrap.min.js}"></script>
    <!-- layer -->
    <script type="text/javascript" th:src="@{/layer/layer.js}"></script>
    <!-- common.js -->
    <script type="text/javascript" th:src="@{/js/common.js}"></script>
</head>
<body>
<div class="panel panel-default">
    <div class="panel-heading">秒杀商品列表</div>
    <table class="table" id="goodslist">
        <tr>
            <td>商品名称</td>
            <td>商品图片</td>
            <td>商品原价</td>
            <td>秒杀价</td>
            <td>库存数量</td>
            <td>详情</td>
        </tr>
        <tr th:each="goods,goodsStat : ${goodsList}">
            <td th:text="${goods.goodsName}"></td>
            <td><img th:src="@{${goods.goodsImg}}" width="100" height="100"/></td>
            <td th:text="${goods.goodsPrice}"></td>
            <td th:text="${goods.seckillPrice}"></td>
            <td th:text="${goods.stockCount}"></td>
            <td><a th:href="'/goods/toDetail/'+${goods.id}">详情</a></td>
        </tr>
    </table>
</div>
</body>
</html>

测试

10.2. 商品详情页

GoodsMapper

GoodsMapper.java

    /**
     * 获取商品详情
     * @param goodsId
     * @return
     */
    GoodsVo findGoodsVoByGoodsId(Long goodsId);

GoodsMapper.xml

    <!-- 获取商品详情 -->
    <select id="findGoodsVoByGoodsId" resultType="com.xxxx.seckill.vo.GoodsVo">
        select
            g.id,
            g.goods_name,
            g.goods_title,
            g.goods_img,
            g.goods_detail,
            g.goods_price,
            g.goods_stock,
            sg.seckill_price,
            sg.stock_count,
            sg.start_date,
            sg.end_date
        from t_goods g
        left join t_seckill_goods sg on g.id=sg.goods_id
        where g.id = #{goodsId}
    </select>

GoodsService

IGoodsService.java

    /**
     * 获取商品详情
     * @param goodsId
     * @return
     */
    GoodsVo findGoodsVoByGoodsId(Long goodsId);

GoodsServiceImpl.java

    /**
     * 获取商品详情
     * @param goodsId
     * @return
     */
    @Override
    public GoodsVo findGoodsVoByGoodsId(Long goodsId) {
        return goodsMapper.findGoodsVoByGoodsId(goodsId);
    }

GoodsController

    /**
     * 跳转商品详情页
     * @param goodsId
     * @param model
     * @param user
     * @return
     */
    @RequestMapping("/toDetail/{goodsId}")
    public String toDetail(@PathVariable Long goodsId, Model model, User user) {
        model.addAttribute("user", user);
        GoodsVo goodsVo = goodsService.findGoodsVoByGoodsId(goodsId);
        Date startDate = goodsVo.getStartDate();
        Date endDate = goodsVo.getEndDate();
        Date nowDate = new Date();
        // 秒杀状态
        int secKillStatus = 0;
        // 秒杀还未开始
        int remainSeconds = 0;
        if (nowDate.before(startDate)) {
            remainSeconds = (int) ((startDate.getTime() - nowDate.getTime())/1000);
        } else if (nowDate.after(endDate)) {
            // 秒杀已结束
            secKillStatus = 2;
            remainSeconds = -1;
        } else {
            // 秒杀中
            secKillStatus = 1;
            remainSeconds = 0;
        }
        model.addAttribute("remainSeconds", remainSeconds);
        model.addAttribute("secKillStatus", secKillStatus);
        model.addAttribute("goods", goodsVo);
        return "goodsDetail";
    }

goodsDetail.html

<!DOCTYPE html>
<html lang="en"
      xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>商品详情</title>
    <!-- jquery -->
    <script type="text/javascript" th:src="@{/js/jquery.min.js}"></script>
    <!-- bootstrap -->
    <link rel="stylesheet" type="text/css" th:href="@{/bootstrap/css/bootstrap.min.css}"/>
    <script type="text/javascript" th:src="@{/bootstrap/js/bootstrap.min.js}"></script>
    <!-- layer -->
    <script type="text/javascript" th:src="@{/layer/layer.js}"></script>
    <!-- common.js -->
    <script type="text/javascript" th:src="@{/js/common.js}"></script>
</head>
<body>
<div class="panel panel-default">
    <div class="panel-heading">秒杀商品详情</div>
    <div class="panel-body">
        <span th:if="${user eq null}"> 您还没有登录，请登陆后再操作<br/></span>
        <span>没有收货地址的提示。。。</span>
    </div>
    <table class="table" id="goods">
        <tr>
            <td>商品名称</td>
            <td colspan="3" th:text="${goods.goodsName}"></td>
        </tr>
        <tr>
            <td>商品图片</td>
            <td colspan="3"><img th:src="@{${goods.goodsImg}}" width="200" height="200"/></td>
        </tr>
        <tr>
            <td>秒杀开始时间</td>
            <td th:text="${#dates.format(goods.startDate, 'yyyy-MM-dd HH:mm:ss')}"></td>
            <td id="seckillTip">
                <input type="hidden" id="remainSeconds" th:value="${remainSeconds}">
                <span th:if="${secKillStatus eq 0}">秒杀倒计时：<span id="countDown" th:text="${remainSeconds}"></span>秒</span>
                <span th:if="${secKillStatus eq 1}">秒杀进行中</span>
                <span th:if="${secKillStatus eq 2}">秒杀已结束</span>
            </td>
            <td>
                <form id="secKillForm" action="/seckill/doSeckill">
                    <input type="hidden" name="goodsId" th:value="${goods.id}">
                    <button class="btn btn-primary btn-block" type="submit" id="buyButton">立即秒杀</button>
                </form>
            </td>
        </tr>
        <tr>
            <td>商品原价</td>
            <td colspan="3" th:text="${goods.goodsPrice}"></td>
        </tr>
        <tr>
            <td>秒杀价</td>
            <td colspan="3" th:text="${goods.seckillPrice}"></td>
        </tr>
        <tr>
            <td>库存数量</td>
            <td colspan="3" th:text="${goods.stockCount}"></td>
        </tr>
    </table>
</div>
</body>
<script>
    $(function () {
        countDown();
    });

    function countDown(){
        var remainSeconds = $("#remainSeconds").val();
        var timeout;
        // 秒杀还未开始
        if (remainSeconds > 0) {
            $("#buyButton").attr("disabled", true);
            timeout = setTimeout(function () {
                $("#countDown").text(remainSeconds-1);
                $("#remainSeconds").val(remainSeconds-1);
                countDown();
            }, 1000);
        } else if (remainSeconds == 0) {
            $("#buyButton").attr("disabled", false);
            // 秒杀进行中
            if (timeout) {
                clearTimeout(timeout);
            }
            $("#seckillTip").html("秒杀进行中");
        } else {
            $("#buyButton").attr("disabled", true);
            $("#seckillTip").html("秒杀已经结束");
        }
    };
</script>
</html>

测试

秒杀未开始

秒杀进行中

秒杀已结束

10.3. 秒杀功能实现

OrderService

IOrderService.java

package com.xxxx.seckill.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.xxxx.seckill.pojo.Order;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.vo.GoodsVo;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author kisen
 * @since 2021-03-14
 */
public interface IOrderService extends IService<Order> {

    /**
     * 秒杀
     * @param user
     * @param goods
     * @return
     */
    Order seckill(User user, GoodsVo goods);
}

OrderServiceImpl.java

package com.xxxx.seckill.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.xxxx.seckill.mapper.OrderMapper;
import com.xxxx.seckill.pojo.Order;
import com.xxxx.seckill.pojo.SeckillGoods;
import com.xxxx.seckill.pojo.SeckillOrder;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IOrderService;
import com.xxxx.seckill.service.ISeckillGoodsService;
import com.xxxx.seckill.service.ISeckillOrderService;
import com.xxxx.seckill.vo.GoodsVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Date;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author kisen
 * @since 2021-03-14
 */
@Service
public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements IOrderService {

    @Autowired
    private ISeckillGoodsService seckillGoodsService;

    @Autowired
    private OrderMapper orderMapper;

    @Autowired
    private ISeckillOrderService seckillOrderService;

    /**
     * 秒杀
     * @param user
     * @param goods
     * @return
     */
    @Override
    public Order seckill(User user, GoodsVo goods) {
        // 秒杀商品表减库存
        SeckillGoods seckillGoods = seckillGoodsService.getOne(new QueryWrapper<SeckillGoods>().eq("goods_id", goods.getId()));
        seckillGoods.setStockCount(seckillGoods.getStockCount() - 1);
        seckillGoodsService.updateById(seckillGoods);
        // 生成订单
        Order order = new Order();
        order.setUserId(user.getId());
        order.setGoodsId(goods.getId());
        order.setDeliveryAddrId(0L);
        order.setGoodsName(goods.getGoodsName());
        order.setGoodsCount(1);
        order.setGoodsPrice(seckillGoods.getSeckillPrice());
        order.setOrderChannel(1);
        order.setStatus(0);
        order.setCreateDate(new Date());
        orderMapper.insert(order);
        // 生成秒杀订单
        SeckillOrder seckillOrder = new SeckillOrder();
        seckillOrder.setUserId(user.getId());
        seckillOrder.setOrderId(order.getId());
        seckillOrder.setGoodsId(goods.getId());
        seckillOrderService.save(seckillOrder);
        return order;
    }
}

SeckillController

package com.xxxx.seckill.controller;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.xxxx.seckill.pojo.Order;
import com.xxxx.seckill.pojo.SeckillOrder;
import com.xxxx.seckill.pojo.User;
import com.xxxx.seckill.service.IGoodsService;
import com.xxxx.seckill.service.IOrderService;
import com.xxxx.seckill.service.ISeckillOrderService;
import com.xxxx.seckill.vo.GoodsVo;
import com.xxxx.seckill.vo.RespBeanEnum;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * @ClassName: SecKillController
 * @Title: seckill
 * @Package: com.xxxx.seckill.controller
 * @Description: 秒杀
 * @Author: Kisen
 * @Date: 2021/3/20 14:59
 */
@Controller
@RequestMapping("/seckill")
public class SecKillController {

    @Autowired
    private IGoodsService goodsService;

    @Autowired
    private ISeckillOrderService seckillOrderService;

    @Autowired
    private IOrderService orderService;

    /**
     * 秒杀
     * @param model
     * @param user
     * @param goodsId
     * @return
     */
    @RequestMapping("/doSeckill")
    public String doSeckill(Model model, User user, Long goodsId) {
        if (user == null) {
            return "login";
        }
        model.addAttribute("user", user);
        GoodsVo goods = goodsService.findGoodsVoByGoodsId(goodsId);
        // 判断库存
        if (goods.getStockCount() < 1) {
            model.addAttribute("errmsg", RespBeanEnum.EMPTY_STOCK.getMessage());
            return "secKillFail";
        }
        // 判断是否重复抢购
        SeckillOrder seckillOrder = seckillOrderService.getOne(new QueryWrapper<SeckillOrder>().eq("user_id", user.getId())
                .eq("goods_id", goodsId));
        if (seckillOrder != null) {
            model.addAttribute("errmsg", RespBeanEnum.REPEATE_ERROR.getMessage());
            return "secKillFail";
        }
        Order order = orderService.seckill(user, goods);
        model.addAttribute("order", order);
        model.addAttribute("goods", goods);
        return "orderDetail";
    }
}

测试

秒杀成功进入订单详情注意查看库存是否正确扣减，订单是否正确生成

库存不足

重复抢购

10.4. 订单详情页

本课程重点针对秒杀，所以订单详情只做简单页面展示，随后得支付等功能也不在本课程体现

OrderDetail.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>订单详情</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <!-- jquery -->
    <script type="text/javascript" th:src="@{/js/jquery.min.js}"></script>
    <!-- bootstrap -->
    <link rel="stylesheet" type="text/css" th:href="@{/bootstrap/css/bootstrap.min.css}" />
    <script type="text/javascript" th:src="@{/bootstrap/js/bootstrap.min.js}"></script>
    <!-- layer -->
    <script type="text/javascript" th:src="@{/layer/layer.js}"></script>
    <!-- common.js -->
    <script type="text/javascript" th:src="@{/js/common.js}"></script>
</head>
<body>
<div class="panel panel-default">
    <div class="panel-heading">秒杀订单详情</div>
    <table class="table" id="order">
        <tr>
            <td>商品名称</td>
            <td th:text="${goods.goodsName}" colspan="3"></td>
        </tr>
        <tr>
            <td>商品图片</td>
            <td colspan="2"><img th:src="@{${goods.goodsImg}}" width="200" height="200" /></td>
        </tr>
        <tr>
            <td>订单价格</td>
            <td colspan="2" th:text="${order.goodsPrice}"></td>
        </tr>
        <tr>
            <td>下单时间</td>
            <td th:text="${#dates.format(order.createDate, 'yyyy-MM-dd HH:mm:ss')}" colspan="2"></td>
        </tr>
        <tr>
            <td>订单状态</td>
            <td >
                <span th:if="${order.status eq 0}">未支付</span>
                <span th:if="${order.status eq 1}">待发货</span>
                <span th:if="${order.status eq 2}">已发货</span>
                <span th:if="${order.status eq 3}">已收货</span>
                <span th:if="${order.status eq 4}">已退款</span>
                <span th:if="${order.status eq 5}">已完成</span>
            </td>
            <td>
                <button class="btn btn-primary btn-block" type="submit" id="payButton">立即支付</button>
            </td>
        </tr>
        <tr>
            <td>收货人</td>
            <td colspan="2">XXX  18012345678</td>
        </tr>
        <tr>
            <td>收货地址</td>
            <td colspan="2">上海市浦东区世纪大道</td>
        </tr>
    </table>
</div>

</body>
</html>

测试
至此，简单的秒杀功能逻辑就完成了，下面进入优化阶段

11.系统压测

11.1. JMeter入门

11.1.1.安装

官网：https://jmeter.apache.org/
下载地址：https:/jmeter.apache.org/download_jmeter.cgi

下载解压后直接在bin目录里双击jmeter.bat即可启动（Linux系统通过jmeter.sh启动）

修改中文
Choose Language->Chinese(Simplified)

11.1.2.简单使用

我们先使用JMeter测试一下商品列表页的接口。
首先创建线程组，步骤：添加->线程（用户）->线程组

Ramp-up指在几秒之内启动指定线程数

创建HTTP请求默认值，步骤：添加->配置元件->HTTP请求默认值

添加测试接口，步骤：添加->取样器->HTTP请求

查看输出结果，步骤：添加->监听器->聚合报告/图形结果/用表格擦看结果

启动即可在监听器看到对应的结果

Linux压测命令：

./jmeter.sh -n -t first.jmx -l result.jtl

11.2.安装MySQL

11.2.1.安装

wget http://repo.mysql.com/mysql57-community-release-el7-10.noarch.rpm

安装mysql的repo源:

rpm -ivh mysql57-community-release-el7-10.noarch.rpm

查看是否安装成功：

yum repolist enabled | grep "mysql.*-community.*"

开始安装：

yum install mysql-community-server

11.2.2.启动服务

服务开关操作：

systemctl status mysqld	#检查mysql运行状态
systemctl start/restart/stop mysqld   #启动/重启/停止mysql
systemctl enable mysqld		#开机启动mysql服务

下图表示MySQL正常运行

11.2.3.修改密码

修改root本地密码：

#查看初始密码
grep 'temporary password' /var/log/mysqld.log
#进入mysql，输入初始秘密
mysql -uroot -p
#修改密码
set password for 'root'@'localhost'=password('root');
#注意如果你的密码简单，必须修改两个全局参数：
set global validate_password_policy=0;
set global validate_password_length=1;

授权所有其他机器登陆:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;
FLUSH PRIVILEGES;
#创建新的database
create database mmall default character set utf8 collate utf8_general_ci;

配置默认编码为utf8：修改/etc/my.cnf配置文件，在[mysqld]下添加编码配置

character_set_server=utf8
#default=character-set=utf8
init_connect='SET NAMES utf8'

11.2.4.访问数据库

输入以下命令，并输入修改后的密码进行登录
mysql -u root -p

远程连接数据库

附：RabbitMQ相关

下载erlang
wget https://github.com/rabbitmq/erlang-rpm/releases/download/v23.3.1/erlang-23.3.1-1.el7.x86_64.rpm
安装erlang
rpm -ivh erlang-23.3.1-1.el7.x86_64.rpm
安装完成后,运行命令来查看你安装的erl版本
erl -version
yum -y install socat
下载RabbitMQ
wget https://github.com/rabbitmq/rabbitmq-server/releases/download/v3.8.14/rabbitmq-server-3.8.14-1.el7.noarch.rpm
安装RabbitMQ
rpm -ivh rabbitmq-server-3.8.14-1.el7.noarch.rpm
启动rabbitmq
systemctl start rabbitmq-server
查看rabbitmq状态
systemctl status rabbitmq-server
设置开机启动rabbitmq
systemctl enable rabbitmq-server

显示所有插件
rabbitmq-plugins list
安装RabbitMQ管控插件（用默认的guest用户）
rabbitmq-plugins enable rabbitmq_management

配置防火墙
查看防火墙开发端口
firewall-cmd --zone=public --list-ports
开发RabbitMQ端口15672以便远程访问
firewall-cmd --zone=public --add-port=15672/tcp --permanent
重启防火墙
firewall-cmd --reload

配置RabbitMQ非本机访问的配置文件
cd /etc/rabbitmq/
vim rabbitmq.config
重启服务
systemctl restart rabbitmq-server