基于SpringBoot、Redis和RabbitMQ的秒杀系统

文章目录

基于SpringBoot、Redis和RabbitMQ的秒杀系统
- 登录功能总结

秒杀系统解决的主要问题：并发读、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。

登录功能总结

一、两次MD5加密

前端：Password=MD5(明文+固定Salt)
后端：Password=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>

编写MD5工具类

public class MD5Util {

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

    private static final String salt = "1a2b3c4d";

    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 saltDB) {
        String formPass = inputPassToFormPass(inputPass);
        String dbPass = formPassToDBPass(formPass, saltDB);
        return dbPass;
    }

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

二、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

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

/**
 * 手机号码校验规则
 */
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 value, ConstraintValidatorContext context) {
        if (required){
            return ValidatorUtil.isMobile(value);
        }else {
            if (StringUtils.isEmpty(value)){
                return true;
            }else {
                return ValidatorUtil.isMobile(value);
            }
        }
    }
}

自定义注解IsMobile

/**
 * 自定义注解验证手机号
 */
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
@Retention(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 {};
}

校验手机号工具类

/**
 * 校验手机号工具类
 */
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();
    }
}

使用方法：直接加在需要校验的字段上

@Data
@NoArgsConstructor
@AllArgsConstructor
public class LoginVo {

    @NotNull
    @IsMobile
    private String mobile;

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

}

登录方法的入参添加@Valid

/**
* 登录
* @return
*/
@RequestMapping("/doLogin")
@ResponseBody
public RespBean doLogin(@Valid LoginVo loginVo) {
   log.info(loginVo.toString());
   return userService.login(loginVo);
}

三、记录用户信息

最常用的就是使用cookie+session记录用户信息

Cookie工具类

/**
 * Cookie工具类
 */
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
     * @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;
        // 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地下转换为小写
            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[] ary = domainName.split("\\:");
            domainName = ary[0];
        }
        return domainName;
    }
}

UUID工具类

/**
 * UUID工具类
 */
public class UUIDUtil {
    public static String uuid() {
        return UUID.randomUUID().toString().replace("-", "");
    }
}

登录业务中加入以下代码

//生成Cookie
String ticket = UUIDUtil.uuid();
request.getSession().setAttribute(ticket,user);
CookieUtil.setCookie(request,response,"userTicket",ticket);

四、分布式Session

之前的代码如果所有操作都在一台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，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。过了一会，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。

4.1、Spring Session配合Redis实现分布式Session

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>

配置redis，修改application.yml

spring:
 redis:
   #超时时间
   timeout: 10000ms
   #服务器地址
   host: xxx.xxx.xxx.xxx
   #服务器端口
   port: 6379
   #数据库
   database: 0
   #密码
   password: root
   lettuce:
     pool:
       #最大连接数，默认8
       max-active: 1024
       #最大连接阻塞等待时间，默认-1
       max-wait: 10000ms
       #最大空闲连接
       max-idle: 200
       #最小空闲连接
       min-idle: 5

完成上述操作后进行用户登录会在redis中产生用户信息相关的数据

4.2、直接将用户信息存入Redis

Redis配置类RedisConfig.java

/**
 * Redis配置类
 */
@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory connectionFactory){
        RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>();
        //key序列器
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        //value序列器
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        //Hash类型 key序列器
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        //Hash类型 value序列器
        redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        redisTemplate.setConnectionFactory(connectionFactory);
        return redisTemplate;
    }
}

修改之前添加cookie的代码

//生成Cookie
String ticket = UUIDUtil.uuid();
redisTemplate.opsForValue().set("user:" + ticket, user);
// request.getSession().setAttribute(ticket,user);
CookieUtil.setCookie(request,response,"userTicket",ticket);

此时有一个弊端：用户登录后直接将用户信息存入Redis中了，没有设置过期时间，cookie过期后，重新登录又会产生新的cookie并加到Redis中。

五、优化登录功能

想象一下用户登录后，随意跳转到其它页面是不是都要传入cookie判断用户是否存在，这样重复琐碎的操作可以使用MVC配置类在传入参数前就进行校验。若没有做此层的优化，后续在秒杀功能时，创建的订单将无用户id，原因就是取不到前面传入的用户信息。

UserArgumentResolver.java

@Component
public class UserArgumentResolver implements HandlerMethodArgumentResolver {

    @Autowired
    private IUserService userService;

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

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

MVC配置类WebConfig.java

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private UserArgumentResolver userArgumentResolver;

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