• 参考snowflake算法，基本思路：

• 序列12位（更格式化的输出后，性能损耗导致每毫秒生成不了这么多，所以可以考虑减少这里的位,不过留着也并无影响）
• 机器位10位

• 毫秒为左移 22位

• 上述几个做或运算后得出一个唯一的数，转10进制后，最大10位，最小7位，string.format来统一为10,format性能影响，导致性能降低3倍左右

FilUtils不想用的话，1太机器可以直接考虑使用1，多机器根据代码配置id
代码如下:

package net.gitosc.lianqu1990.utils.code;import net.gitosc.lianqu1990.utils.date.DateFormatUtils;
import net.gitosc.lianqu1990.utils.date.TimeMark;
import org.apache.commons.io.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.io.File;/*** 缺陷是，订单量没那么大，导致机器码|序列 后，一般都是4096* 通过将毫秒引入序列后修正* 后来加了format以后性能受损，比idcenter慢10倍，每秒可以生成50w，idcenter将近500w，不过这也是idcenter极限* 够用，暂不优化* @author hanchao* @date 2017/4/20 19:01*/
public class OrderNoCenter {public static final Logger logger = LoggerFactory.getLogger(OrderNoCenter.class);private static final String WORKERID_PATH = "/etc/workerId";private OrderNoCenter() {}private static class OrderNoCenterHolder{private static OrderNoCenter instance = new OrderNoCenter();}public static OrderNoCenter getInstance() {return OrderNoCenterHolder.instance;}/*** 节点 ID 默认取1*/private long workerId = 1;/*** 序列id 默认取1*/private long sequence = 1;/*** 机器标识位数*/private final long workerIdBits = 10L;/*** 机器ID最大值*/private final long maxWorkerId = -1L ^ (-1L << workerIdBits); //结果就是2的workerBits次方-1,能表示的最大数.全部1亦或10位0，就是0开头最后10位1/*** 毫秒内自增位*/private final long sequenceBits = 12L;/*** 机器ID偏左移12位*/private final long workerIdShift = sequenceBits;/*** 数据中心ID左移17位*/private final long datacenterIdShift = sequenceBits + workerIdBits;private final long sequenceMask = -1L ^ (-1L << sequenceBits);/*** 时间毫秒左移22位*/private final long timestampLeftShift = sequenceBits + workerIdBits;private long lastTimestamp = -1L;public void initParam() {// 从默认位置读取workerId,最大1024try {File conf = new File(WORKERID_PATH);if(conf.exists()){String str = FileUtils.readFileToString(conf);workerId = Integer.parseInt(str);}else{logger.warn(" worker id not found,will use default value...");}} catch(Exception e){e.printStackTrace();}logger.info(" worker id is {}",workerId);if (workerId < 0 || workerId > maxWorkerId) {throw new IllegalArgumentException("workerId is illegal: "+ workerId);}}public long getWorkerId() {return workerId;}public long getTime() {return System.currentTimeMillis();}public String create() {return nextNo();}/*** 获取id 线程安全** @return*/private synchronized String nextNo() {long timestamp = timeGen();// 时间错误if (timestamp < lastTimestamp) {throw new IllegalStateException("Clock moved backwards.");}// 当前毫秒内，则+1if (lastTimestamp == timestamp) {// 当前毫秒内计数满了，则等待下一秒sequence = (sequence + 1) & sequenceMask;if (sequence == 0) {timestamp = tilNextMillis(lastTimestamp);}} else {sequence = 0;}lastTimestamp = timestamp;// ID偏移组合生成最终的ID，并返回ID,最大十位数long id = ((timestamp % 1000) << timestampLeftShift) | (workerId << workerIdShift) | sequence;String timestampStr = DateFormatUtils.NUMBER_FORMAT.format(timestamp);return timestampStr+String.format("%010d",id);}/*** 等待下一个毫秒的到来** @param lastTimestamp* @return*/private long tilNextMillis(long lastTimestamp) {long timestamp = timeGen();while (timestamp <= lastTimestamp) {timestamp = timeGen();}return timestamp;}private long timeGen() {return System.currentTimeMillis();}/*** 最大十位，最小7位,补0format*//*public void test(){String t = String.valueOf((1L << 22) | (1 << 12) | 0);String t1 = String.valueOf((999L << 22) | (1023 << 12) | 0);System.out.println(DateFormatUtils.NUMBER_FORMAT.format(System.currentTimeMillis())+"-"+t);System.out.println(DateFormatUtils.NUMBER_FORMAT.format(System.currentTimeMillis())+"-"+t1);long l1 = (1L << 22) | (1 << 12) | 0;long l2 = (999L << 22) | (1023 << 12) | 0;System.out.println(l1);System.out.println(l2);System.out.println(String.format("%010d",l1));System.out.println(String.format("%010d",l2));}*/public static void main(String[] args){for (int i = 0; i < 100; i++) {System.out.println(OrderNoCenter.getInstance().create());}//性能测试TimeMark mark = new TimeMark();for (int i = 0; i < 1000000; i++) {OrderNoCenter.getInstance().create();}mark.simplePrint();mark.mark();for (int i = 0; i < 1000000; i++) {IdCenter.getInstance().getId();}mark.simplePrint();}
}

缺少代码的话，请直接使用我的附件代码

附件：
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