content: package com.cf.framework.utils;
  
  import java.text.SimpleDateFormat;
  import java.util.Date;
  
  /**
   * Created by mrt on 2020/3/27.
   */
  public class GenerateOrderNum {
      /**
       * 锁对象，可以为任意对象
       */
      private static Object lockObj = "lockerOrder";
      /**
       * 订单号生成计数器
       */
      private static long orderNumCount = 0L;
      /**
       * 每毫秒生成订单号数量最大值
       */
      private int maxPerMSECSize=1000;
  
      /**
       *
       */
  
      /**
       * 生成非重复订单号，理论上限1毫秒1000个，可扩展
       * @param tname 测试用
       */
      public synchronized void generate(String tname) {
          try {
              // 最终生成的订单号
              String finOrderNum = "";
              synchronized (lockObj) {
                  // 取系统当前时间作为订单号变量前半部分，精确到毫秒
                  long nowLong = Long.parseLong(new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date()));
                  // 计数器到最大值归零，可扩展更大，目前1毫秒处理峰值1000个，1秒100万
                  if (orderNumCount >= maxPerMSECSize) {
                      orderNumCount = 0L;
                  }
                  //组装订单号
                  String countStr=maxPerMSECSize +orderNumCount+"";
                  finOrderNum=nowLong+countStr.substring(1);
                  orderNumCount++;
                  System.out.println(finOrderNum + "--" + Thread.currentThread().getName() + "::" + tname );
                  // Thread.sleep(1000);
              }
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  
      public static void main(String[] args) {
          // 测试多线程调用订单号生成工具
          /*try {
              for (int i = 0; i < 200; i++) {
                  Thread t1 = new Thread(new Runnable() {
                      public void run() {
                          GenerateOrderNum generateOrderNum = new GenerateOrderNum();
                          generateOrderNum.generate("a");
                      }
                  }, "at" + i);
                  t1.start();
  
                  Thread t2 = new Thread(new Runnable() {
                      public void run() {
                          GenerateOrderNum generateOrderNum = new GenerateOrderNum();
                          generateOrderNum.generate("b");
                      }
                  }, "bt" + i);
                  t2.start();
              }
          } catch (Exception e) {
              e.printStackTrace();
          }*/
          System.out.println(System.currentTimeMillis());
      }
  }
  