訂單號組成：年月日時分秒+4位累加數字
訂單號：201601031458300001
說明：前14位是瞬時時間，後4位是當天的點單號，每天從1開始記：
程式碼如下：

package com.jfl.action;

import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import
 
 com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class GetOrderNum extends ActionSupport{

        public String getOrderNum(){
            SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
            SimpleDateFormat sdf1 = new SimpleDateFormat("dd"
 
);
            String time = sdf.format(new Date());
            String day = sdf1.format(new Date());

            HttpServletRequest request = ServletActionContext.getRequest();
            Map application = ActionContext.getContext().getApplication();

            int count;
            String dayPass = null
 
;
            if(!application.containsKey("count")){
                     count=0;
            }else{
                if(!application.containsKey("dayPass")){
                    application.put("dayPass", day);
                }else{
                    dayPass = (String) application.get("dayPass");
                }
                if(!day.equals(dayPass)){
                    count=0; 
                }
                    count=(Integer) application.get("count");
                }

            count = count+1;
            application.put("count", count);
            DecimalFormat df = new DecimalFormat("0000");
            String num = df.format(count);
            String orderNum = time+""+num;
            request.setAttribute("orderNum", orderNum);

            return "showOrderNum";
        }
}