redis每天生成自增流水号(001、002...)

原理:
利用redis的RedisAtomicLong类实现该功能:
让其每天第一次放置一个新的自增的值(一天过期)
然后和每天的日期相加就可以了
例子: 20180901 + 001 ;当天就是 20180901 + 002
如果要多少个0,可以自己配置(工具类中)

一、pom.xml配置

<!-- redis -->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-redis</artifactId>
  <version>1.7.2.RELEASE</version>
</dependency>

二、redisTemplate配置

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.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class RedisConfig {
    /**
     * retemplate相关配置
     * @param factory
     * @return
     */
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {

        RedisTemplate<String, Object> template = new RedisTemplate<>();
        // 配置连接工厂
        template.setConnectionFactory(factory);

        //使用Jackson2JsonRedisSerializer来序列化和反序列化redis的value值（默认使用JDK的序列化方式）
        Jackson2JsonRedisSerializer jacksonSeial = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper om = new ObjectMapper();
        // 指定要序列化的域，field,get和set,以及修饰符范围，ANY是都有包括private和public
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        // 指定序列化输入的类型，类必须是非final修饰的，final修饰的类，比如String,Integer等会跑出异常
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jacksonSeial.setObjectMapper(om);

        // 值采用json序列化
        template.setValueSerializer(jacksonSeial);
        //使用StringRedisSerializer来序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());

        // 设置hash key 和value序列化模式
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(jacksonSeial);
        template.afterPropertiesSet();

        return template;
    }
}

三、代码实现

import java.util.Set;
import java.util.concurrent.TimeUnit;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.support.atomic.RedisAtomicLong;
import org.springframework.stereotype.Component;
@Component
public class CacheService { 

         //这里因为有其他的template,所以名字起得不好看
        @Autowired
          RedisTemplate<String, Object> ObjectRedisTemplate;

        public Long getIncrementNum(String key) {
        // 不存在准备创建 键值对
        RedisAtomicLong entityIdCounter = new RedisAtomicLong(key, redisTemplate.getConnectionFactory());
        Long counter = entityIdCounter.incrementAndGet();
        if ((null == counter || counter.longValue() == 1)) {// 初始设置过期时间
            System.out.println("设置过期时间为1天!");
            entityIdCounter.expire(1, TimeUnit.DAYS);// 单位天
        }
        return counter;
    }
}

四、工具类（可以直接添加方法）

public class SequenceUtils {

    static final int DEFAULT_LENGTH = 3;

    public static String getSequence(long seq) {
        String str = String.valueOf(seq);
        int len = str.length();
        if (len >= DEFAULT_LENGTH) {// 取决于业务规模,应该不会到达3
            return str;
        }
        int rest = DEFAULT_LENGTH - len;
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < rest; i++) {
            sb.append('0');
        }
        sb.append(str);
        return sb.toString();
    }
}

五、测试

 String currentDate = new SimpleDateFormat("yyyyMMdd").format(new Date());
        Long num = cacheService.getIncrementNum("demo_get_the_new_" + "test3_"+currentDate);
        String flowCode = SequenceUtils.getSequence(num);
        logger.info("流水号: " + flowCode);

六、控制台输出

设置过期时间为1天!
流水号0001

设置过期时间为1天!
流水号0002