Java自增流水号生成

古城微笑少年丶 2022-11-19 11:27 486阅读 0赞

### redis自增流水号生成 ###

**需求如下:**

**单号生成规则： “4位年份”+“1位渠道”+“6位流水号”+“1位校验”**

其中6位渠道的生成和本篇文章的内容主角:redis有关

6位流水号——从“000001”开始，到“999999”结束；

看下面这个数据结构(本地搭建redis，用redis客户端做实验)

127.0.0.1:6379> set visitors 0
    OK
    127.0.0.1:6379> incr visitors
    (integer) 1
    127.0.0.1:6379> incr visitors
    (integer) 2
    127.0.0.1:6379> incr visitors
    (integer) 3
    127.0.0.1:6379>

关键的两条命令:

`SET key value` 设置key=value

`INCR key` 增加键的整数值一次

实现代码:

备注:incr默认每次增长1

public static String serialNo(String key)
    	{
    		String currData = callDate();		
    		String currTime = String.valueOf(System.currentTimeMillis());
    		
    		String ret = String.valueOf(redisService.incr(key));		
    		return currData.substring(0,4) + "3" + "000000".substring(ret.length()) + ret + currTime.substring(currTime.length() - 1);
    	}
    	
    	public static String callDate()
    	{
    		SimpleDateFormat format0 = new SimpleDateFormat("yyyyMMdd");
    		Date date = new Date();
    		return format0.format(date.getTime());
    	}

202130000179
    
    202130000186
    
    202130000198

改造:每次增长3

public static void main(String[] args) throws Exception { 
    		ApplicationContext context=new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
    
    		RedisUtil redisUtil=(RedisUtil) context.getBean("redisUtil");
    		String currData = callDate();
    		String currTime = String.valueOf(System.currentTimeMillis());
    
    		String ret = String.valueOf(redisUtil.incr("bank-becontno-key",3));
    
    		System.out.println(currData.substring(0,4) + "3" + "000000".substring(ret.length()) + ret + currTime.substring(currTime.length() - 1));
    
    	}
    
    	public static String callDate()
    	{ 
    		SimpleDateFormat format0 = new SimpleDateFormat("yyyyMMdd");
    		Date date = new Date();
    		return format0.format(date.getTime());
    	}
    
    	
    }

RedisUtil

public class RedisUtil {
    	private RedisTemplate<String, Object> redisTemplate;
    	
    	public void setRedisTemplate(RedisTemplate<String, Object> redisTemplate) {
    		this.redisTemplate = redisTemplate;
    	}
    public  long incr(String key, long delta){
    		if(delta<0){
    			throw new RuntimeException("递增因子必须大于0");
    		}
    		return redisTemplate.opsForValue().increment(key, delta);
        }
        }