Springboot+redis+Vue實現秒殺的項目實踐
1、Redis簡介
Redis是一個開源的key-value存儲系統。
Redis的五種基本類型:String(字符串),list(鏈表),set(集合),zset(有序集合),hash,stream(Redis5.0後的新數據結構)
這些數據類型都支持push/pop、add/remove及取交集並集和差集及更豐富的操作,而且這些操作都是原子性的。
Redis的應用場景為配合關系型數據庫做高速緩存,降低數據庫IO
需要註意的是,Redis是單線程的,如果一次批量處理命令過多,會造成Redis阻塞或網絡擁塞(傳輸數據量大)
2、實現代碼
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.1.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>org.example</groupId> <artifactId>seckill</artifactId> <version>1.0-SNAPSHOT</version> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <version>2.2.1.RELEASE</version> <scope>test</scope> </dependency> <!-- redis --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <!-- spring2.X集成redis所需common-pool2--> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>2.6.0</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.24</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <fork>true</fork> </configuration> </plugin> </plugins> </build> </project>
application.properties.xml
#Redis服務器地址 spring.redis.host=192.168.1.2 #Redis服務器連接端口 spring.redis.port=6379 #Redis數據庫索引(默認為0) spring.redis.database=0 #連接超時時間(毫秒) spring.redis.timeout=1800000 #連接池最大連接數(使用負值表示沒有限制) spring.redis.lettuce.pool.max-active=20 #最大阻塞等待時間(負數表示沒限制) spring.redis.lettuce.pool.max-wait=-1 #連接池中的最大空閑連接 spring.redis.lettuce.pool.max-idle=5 #連接池中的最小空閑連接 spring.redis.lettuce.pool.min-idle=0 # 關閉超時時間 #pring.redis.lettuce.shutdown-timeout=100 #配置spring啟動端口號 server.port=8080
前端界面
seckillpage.html
<!DOCTYPE html> <html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml" xmlns:v-bind="http://www.w3.org/1999/xhtml"> <head> <meta charset="UTF-8"> <title>redis秒殺</title> </head> <body> <!-- 開發環境版本,包含瞭有幫助的命令行警告 --> <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script> <!-- 官網提供的 axios 在線地址 --> <script src="https://cdn.bootcdn.net/ajax/libs/axios/0.20.0-0/axios.min.js"></script> <div id="app"> <h1>商品1元秒殺</h1> <!-- 左箭頭 --> <input type="button" value="<" v-on:click="prov" v-show="this.index>-1"/> <img v-bind:src="imgArr[index]" width="200px" /> <!-- 右箭頭 --> <input type="button" value=">" v-on:click="next" v-show="this.index<2"/><br> <input type="button" v-on:click="seckill" value="秒 殺"/> </div> <script> var app = new Vue({ el: "#app", data: { productId: "01234", imgArr:[ "/image/phone1.png", "/image/phone2.png", "/image/phone3.png", ], index:0 }, methods: { seckill: function () { let param = new URLSearchParams() param.append('productId', this.productId) param.append('index', this.index) axios({ method: 'post', url: 'http://192.168.1.6:8080/index/doSeckill', data: param }).then(function (response) { if (response.data == true) { alert("秒殺成功"); } else { alert("搶光瞭"); } }, function(error){ alert("發生錯誤"); }); }, prov:function(){ this.index--; }, next:function(){ this.index++; } } }); </script> </body> </html>
相關配置類
Redis配置類
RedisConfig.java
package com.springboot_redis_seckill.config; import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.cache.CacheManager; import org.springframework.cache.annotation.CachingConfigurerSupport; import org.springframework.cache.annotation.EnableCaching; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.cache.RedisCacheConfiguration; import org.springframework.data.redis.cache.RedisCacheManager; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; import org.springframework.data.redis.serializer.RedisSerializationContext; import org.springframework.data.redis.serializer.RedisSerializer; import org.springframework.data.redis.serializer.StringRedisSerializer; import java.time.Duration; /** * @author WuL2 * @create 2021-05-27 14:26 * @desc **/ @EnableCaching @Configuration public class RedisConfig extends CachingConfigurerSupport { @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> template = new RedisTemplate<>(); RedisSerializer<String> redisSerializer = new StringRedisSerializer(); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); template.setConnectionFactory(factory); template.setKeySerializer(redisSerializer); //key序列化方式 template.setValueSerializer(jackson2JsonRedisSerializer); //value序列化 template.setHashValueSerializer(jackson2JsonRedisSerializer); //value hashmap序列化 return template; } @Bean(name = "cacheManager") public CacheManager cacheManager(RedisConnectionFactory factory) { RedisSerializer<String> redisSerializer = new StringRedisSerializer(); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); //解決查詢緩存轉換異常的問題 ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); // 配置序列化(解決亂碼的問題),過期時間600秒 RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig() .entryTtl(Duration.ofSeconds(600)) .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer)) .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer)) .disableCachingNullValues(); RedisCacheManager cacheManager = RedisCacheManager.builder(factory) .cacheDefaults(config) .build(); return cacheManager; } }
配置Vue獲取後端接口數據時出現的跨域請求問題。
CorsConfig.java
package com.springboot_redis_seckill.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.cors.CorsConfiguration; import org.springframework.web.cors.UrlBasedCorsConfigurationSource; import org.springframework.web.filter.CorsFilter; /** * @author: wu linchun * @time: 2021/5/28 22:22 * @description: 解決跨域問題(接口是http,而axios一般請求的是https。從https到http是跨域,因此要配置跨域請求) */ @Configuration public class CorsConfig { private CorsConfiguration buildConfig() { CorsConfiguration corsConfiguration = new CorsConfiguration(); corsConfiguration.addAllowedOrigin("*"); //允許任何域名 corsConfiguration.addAllowedHeader("*"); //允許任何頭 corsConfiguration.addAllowedMethod("*"); //允許任何方法 return corsConfiguration; } @Bean public CorsFilter corsFilter() { UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource(); source.registerCorsConfiguration("/**", buildConfig()); //註冊 return new CorsFilter(source); } }
服務層
SecKillService.java
package com.springboot_redis_seckill.service; public interface SecKillService { public boolean doSecKill(String uid,String productId); }
SecKillServiceImpl.java
package com.springboot_redis_seckill.service.impl; import com.springboot_redis_seckill.service.SecKillService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.stereotype.Service; /** * @author WuL2 * @create 2021-05-27 14:53 * @desc **/ @Service public class SecKillServiceImpl implements SecKillService { @Autowired @Qualifier("redisTemplate") private RedisTemplate redisTemplate; @Override public synchronized boolean doSecKill(String uid, String productId) { //1、uid和productId非空判斷 if (uid == null || productId == null) { return false; } //2、拼接key String kcKey = "sk:" + productId + ":qt"; //庫存 String userKey = "sk:" + productId + ":user"; //秒殺成功的用戶 //3、獲取庫存 String kc = String.valueOf(redisTemplate.opsForValue().get(kcKey)) ; if (kc == null) { System.out.println("秒殺還沒有開始,請等待"); return false; } //4、判斷用戶是否已經秒殺成功過瞭 if (redisTemplate.opsForSet().isMember(userKey, uid)) { System.out.println("已秒殺成功,不能重復秒殺"); return false; } //5、如果庫存數量小於1,秒殺結束 if (Integer.parseInt(kc) <=0) { System.out.println("秒殺結束"); return false; } //6、秒殺過程 redisTemplate.opsForValue().decrement(kcKey); //庫存數量減1 redisTemplate.opsForSet().add(userKey, uid); System.out.println("秒殺成功。。。"); return true; } }
控制層
package com.springboot_redis_seckill.controller; import com.alibaba.fastjson.JSONObject; import com.springboot_redis_seckill.service.SecKillService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.util.Random; /** * @author WuL2 * @create 2021-05-27 14:28 * @desc **/ @Controller @RequestMapping("/index") public class MyController { @Autowired @Qualifier("secKillServiceImpl") private SecKillService secKillService; @RequestMapping(value = {"/seckillpage"}, method = RequestMethod.GET) public String seckillpage() { return "/html/seckillpage.html"; } @RequestMapping(value = {"/doSeckill"}, method = RequestMethod.POST) @ResponseBody //自動返回json格式的數據 public Object doSeckill(HttpServletRequest request, HttpServletResponse response) { System.out.println("doSeckill"); String productId = request.getParameter("productId"); String index = request.getParameter("index"); System.out.println(productId+index); //拼接成為商品ID int id = new Random().nextInt(50000); //使用隨機數生成用戶ID String uid = String.valueOf(id) + " "; boolean flag = secKillService.doSecKill(uid, productId+index); System.out.println(flag); return flag; } }
啟動類
RunApplication.java
package com.springboot_redis_seckill; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; /** * @author WuL2 * @create 2021-05-27 14:32 * @desc **/ @SpringBootApplication public class RunApplication { public static void main(String[] args) { SpringApplication.run(RunApplication.class, args); } }
3、啟動步驟
因為一共有三件商品要秒殺,所以在redis裡面設置三個商品的庫存數量。這裡數量都設置為10。
127.0.0.1:6379> set sk:012340:qt 10 OK 127.0.0.1:6379> set sk:012341:qt 10 OK 127.0.0.1:6379> set sk:012342:qt 10 OK
要確保redis能夠被訪問,要確保關閉linux的防火墻,以及關閉redis的保護模式。
vim redis.conf --打開redis配置 service iptables stop --關閉防火墻 //關閉redis保護模式 redis-cli --進入redis客戶端 config set protected-mode "no" --配置裡面關閉redis保護模式(隻是進入redis.conf把protected-mode變為no是不行的,還要加一句config set protected-mode "no"
啟動springboot項目
秒殺成功後,該商品在redis中的數量就減1。
當數量減為0時,則提示“搶光瞭”。
4、使用ab進行並發測試
如果是centOS 6版本的linux都是默認按照瞭ab工具的。
如果沒有安裝ab工具,可在linux終端用命令聯網下載安裝。
yum install httpd-tools
安裝完成後,就可以使用ab工具進行並發測試瞭。
在linux終端輸入如下命令:
ab -n 2000 -c 200 -p '/root/Desktop/post.txt' -T 'application/x-www-form-urlencoded' 'http://192.168.1.6:8080/index/doSeckill/'
012341這個商品庫存變為0瞭
5、線程安全
為瞭防止出現“超買”的現象,需要讓操作redis的方法是線程安全的(即在方法上加上一個“悲觀鎖”synchronized)。
如果不加synchronized就會出現“超買”現象,即redis庫存會出現負數
之所以產生這種現象是由於並發導致多個用戶同時調用瞭doSecKill()方法,多個用戶同時修改瞭redis中的sk:012342:qt的值,但暫時都沒有提交存入到redis中去。等到後來一起提交,導致瞭sk:012342:qt的值被修改瞭多次,因此會出現負數。
因此在doSecKill()方法加上悲觀鎖,用戶調用該方法就對該方法加鎖,修改瞭sk:012342:qt的值後並提交存入redis中之後,才會釋放鎖。其他用戶才能得到鎖並操作該方法。
6、總結
redis作為一種Nosql的非關系型數據庫,因為其單實例,簡單高效的特性通常會被作為其他關系型數據庫的高速緩存。尤其是在秒殺這樣的高並發操作。先將要秒殺的商品信息從數據庫讀入到redis中,秒殺的過程實際上是在與redis進行交互。等秒殺完成後再將秒殺的結果存入數據庫。可以有效降低降低數據庫IO,防止數據庫宕機。
7、參考資料
https://www.bilibili.com/video/BV1Rv41177Af?p=27
https://www.cnblogs.com/taiyonghai/p/5810150.html
到此這篇關於Springboot+redis+Vue實現秒殺的項目實踐的文章就介紹到這瞭,更多相關Springboot+redis+Vue 秒殺內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!
推薦閱讀:
- springboot2.5.0和redis整合配置詳解
- 解決SpringBoot下Redis序列化亂碼的問題
- 使用註解實現Redis緩存功能
- springboot使用redis的詳細步驟
- Springboot項目中使用redis的配置詳解