分库分表之后，id 主键如何处理？

UUID.randomUUID().toString().replace(“-”, “”) -> sfsdf23423rr234sfdaf

0 | 0001100 10100010 10111110 10001001 01011100 00 | 10001 | 1 1001 | 0000 00000000

public class IdWorker {

private long workerId;
private long datacenterId;
private long sequence;

public IdWorker(long workerId, long datacenterId, long sequence) {
// sanity check for workerId
// 这儿不就检查了一下，要求就是你传递进来的机房id和机器id不能超过32，不能小于0
if (workerId > maxWorkerId || workerId < 0) {
throw new IllegalArgumentException(
                    String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
        }
if (datacenterId > maxDatacenterId || datacenterId < 0) {
throw new IllegalArgumentException(
                    String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
        }
        System.out.printf(
"worker starting. timestamp left shift %d, datacenter id bits %d, worker id bits %d, sequence bits %d, workerid %d",
                timestampLeftShift, datacenterIdBits, workerIdBits, sequenceBits, workerId);

this.workerId = workerId;
this.datacenterId = datacenterId;
this.sequence = sequence;
    }

private long twepoch = 1288834974657L;

private long workerIdBits = 5L;
private long datacenterIdBits = 5L;

// 这个是二进制运算，就是 5 bit最多只能有31个数字，也就是说机器id最多只能是32以内
private long maxWorkerId = -1L ^ (-1L << workerIdBits);

// 这个是一个意思，就是 5 bit最多只能有31个数字，机房id最多只能是32以内
private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
private long sequenceBits = 12L;

private long workerIdShift = sequenceBits;
private long datacenterIdShift = sequenceBits + workerIdBits;
private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
private long sequenceMask = -1L ^ (-1L << sequenceBits);

private long lastTimestamp = -1L;

public long getWorkerId() {
return workerId;
    }

public long getDatacenterId() {
return datacenterId;
    }

public long getTimestamp() {
return System.currentTimeMillis();
    }

public synchronized long nextId() {
// 这儿就是获取当前时间戳，单位是毫秒
long timestamp = timeGen();

if (timestamp < lastTimestamp) {
            System.err.printf("clock is moving backwards. Rejecting requests until %d.", lastTimestamp);
throw new RuntimeException(String.format(
"Clock moved backwards. Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));
        }

if (lastTimestamp == timestamp) {
// 这个意思是说一个毫秒内最多只能有4096个数字
// 无论你传递多少进来，这个位运算保证始终就是在4096这个范围内，避免你自己传递个sequence超过了4096这个范围
            sequence = (sequence + 1) & sequenceMask;
if (sequence == 0) {
                timestamp = tilNextMillis(lastTimestamp);
            }
        } else {
            sequence = 0;
        }

// 这儿记录一下最近一次生成id的时间戳，单位是毫秒
        lastTimestamp = timestamp;

// 这儿就是将时间戳左移，放到 41 bit那儿；
// 将机房 id左移放到 5 bit那儿；
// 将机器id左移放到5 bit那儿；将序号放最后12 bit；
// 最后拼接起来成一个 64 bit的二进制数字，转换成 10 进制就是个 long 型
return ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << datacenterIdShift)
                | (workerId << workerIdShift) | sequence;
    }

private long tilNextMillis(long lastTimestamp) {
long timestamp = timeGen();
while (timestamp <= lastTimestamp) {
            timestamp = timeGen();
        }
return timestamp;
    }

private long timeGen() {
return System.currentTimeMillis();
    }

// ---------------测试---------------
public static void main(String[] args) {
        IdWorker worker = new IdWorker(1, 1, 1);
for (int i = 0; i < 30; i++) {
            System.out.println(worker.nextId());
        }
    }

}