java 使用UUID生成19随机单号 纯数字，数字+字母唯一不重复单号

/**
* Created by cc
* 生成订单号
* uuid: db30cc85-3387-4845-87bc-dc390b55b7ea 前8位 + 201508171108900(yyMMddHHMMSS)
* 即： db30cc85201508171108900
*/
public class OrderNoUtil {

public static  String getOrderNo(){
String orderNo = "" ;
UUID uuid = UUID.randomUUID();
 String trandNo = String.valueOf((Math.random() * 9 + 1) * 1000000);
String sdf = new SimpleDateFormat("yyyyMMddHHMMSS").format(new Date());
orderNo = uuid.toString().substring(0, 8);
orderNo = orderNo + sdf ;
return orderNo ;
}

//生成19随机单号 纯数字
 public static String getOrderNo(){ String orderNo = "" ; String trandNo = String.valueOf((Math.random() * 9 + 1) * 1000000); String sdf = new SimpleDateFormat("yyyyMMddHHMMSS").format(new Date()); orderNo = trandNo.toString().substring(0, 4); orderNo = orderNo + sdf ; return orderNo ; }}