Redis实现全局唯一id生成

Redis实现全局唯一id生成

废话不多说直接上代码

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.concurrent.TimeUnit;

/**
 * 描述:
 * 唯一ID生成器
 * @author jimmy
 * @create 2020-11-06 16:06
 */
@Component
public class GenerateIDUtil {

    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 生成每天的初始Id
     * @param key
     * @return
     */  public String initPrimaryId(String key) {
        Assert.hasLength(key, "hashName不能为空");
        String hashCol = LocalDate.now().format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        //自定义编号规则
        String hashColVal = hashCol + "00001";
//        redisTemplate.opsForHash().putIfAbsent(hashName, hashCol, hashColVal);

        Long expiresTime = getSecondsNextEarlyMorning();
        redisTemplate.opsForValue().set(key, Long.valueOf(hashColVal), expiresTime, TimeUnit.SECONDS);
        return hashColVal;
    }


    /**
     * 获取分布式Id     
     * @param key
     * @return
     */
    public String getPrimaryId(String key) {

        String id = "";
        if(redisTemplate.hasKey(key)){
            // redisTemplate.opsForValue().get(key);
            // redisTemplate.delete(key);
            id = String.valueOf(redisTemplate.opsForValue().increment(key, 1));
        } else {
            id = initPrimaryId(key);
        }
        return id;
    }


    /**
     * 判断当前时间距离第二天凌晨的秒数
     * @return 返回值单位为[s:秒]
     */
    public Long getSecondsNextEarlyMorning() {
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DAY_OF_YEAR, 1);
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.MILLISECOND, 0);
        return (cal.getTimeInMillis() - System.currentTimeMillis()) / 1000;
    }
}

写法很简单，没什么可说的。