redis自增

一, 引入依賴:

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId><version>2.6.5</version>
</dependency>

二, 配置信息:

spring:redis:# 地址host: localhost# 端口號port: 6379# 密碼password:# 超時時間，單位毫秒timeout: 3000# 數據庫編號database: 0

JedisConfig:

package org.com.spi.config;import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
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.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;@Configuration
public class JedisConfig {@Beanpublic RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {StringRedisTemplate template = new StringRedisTemplate(factory);//定義key序列化方式//RedisSerializer<String> redisSerializer = new StringRedisSerializer();//Long類型會出現異常信息;需要我們上面的自定義key生成策略，一般沒必要//定義value的序列化方式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.setKeySerializer(redisSerializer);template.setValueSerializer(jackson2JsonRedisSerializer);template.setHashValueSerializer(jackson2JsonRedisSerializer);template.afterPropertiesSet();return template;}
}

三, redis配置類RedisUtils:

package org.com.spi.utils;import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;import javax.annotation.Resource;@Component
public class RedisUtils {@Resourceprivate RedisTemplate<String, Object> redisTemplate; //這里使用的是redisTemplate/*** redis 自增* @param key 鍵//     * @param by 要增加幾(大于0)* @return*/public long incr(String key, long delta){if(delta<0){throw new RuntimeException("遞增因子必須大于0");}return redisTemplate.opsForValue().increment(key, delta);}
}

4, 編寫接口controller:

@Autowired
RedisUtils redisUtils;
/*** 根據數據庫ID自增生成主鍵* 缺點在于數據庫不能集群，只能單機搞，不適合ID作為業務傳遞的場景*/
@PostMapping("/redisInc")
public Long redisInc(){return redisUtils.incr("generate2",1);
}

特點: redis自增僅適合單業務場景,對于多模塊、復雜業務場景不太適用;另外,redis的兩種持久化機制都有一定的弊端: RDB方式-宕機存在丟失的風險, AOF方式-宕機能恢復數據,但數據恢復時間較長,在并發量大的時候可能導致ID重復的情況.

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雪花算法

主要類: IdWorker

package org.com.spi.config;import org.springframework.stereotype.Component;import java.lang.management.