微信二维码是永久的吗 微信永久二维码的有效利用

1、微信生成带参数的二维码

生成带参数的二维码

文档中有这么一句话，“永久二维码，是无过期时间的，但数量较少（目前为最多10万个）。”

为了减少永久二维码的生成，在实际开发中应该灵活地重复使用被废弃掉的永久二维码。所谓的“被废弃掉的”，举例说明，一个会议报名的永久二维码，当且仅当该会议结束了，该会议报名的永久二维码就可以被其他有有效的会议再次使用。

2、开发实例说明 2.1 表结构

-- Create table
create table
(
  id          number(10) not null,
  meeting_id  number(10),
  type        number(2),
  ticket      varchar2(200),
  scene_id    number(10),
  create_time number
)
;
-- Add comments to the columns 
comment on column .id
  is 'ID';
comment on column .meeting_id
  is '会议ID';
comment on column .type
  is '类型1.报名；2.签到';
comment on column .ticket
  is '微信ticket';
comment on column .scene_id
  is '场景id';
comment on column .create_time
  is '创建时间';

2.2 SQL编写

-- 查询一条最新会议的签到结束的永久二维码记录
select *
  from (select a.*
          from (select * from meeting_permanent_qrcode where type = 1) a
         inner join (select id from meeting where status = 3) b
            on a.meeting_id = b.id
         order by a.create_time desc)
 where rownum < 2

2.3 Java 编写

/**
 * 查看报名页二维码
 *
 * @param meeting_id
 */
public void viewRegistrationQrcode(Model model, String meeting_id) {
    try {
        Map filter = new HashMap();
        filter.put("meeting_id", meeting_id);
        filter.put("type", 1L);
        MeetingPermanentQrcodeFormMap meetingPermanentQrcodeFormMap = meetingPermanentQrcodeMapper.selectMeetingPermanentQrcodeBy(filter);
        String ticket = null;
        if (meetingPermanentQrcodeFormMap != null) {
            ticket = meetingPermanentQrcodeFormMap.getStr("ticket");
        }
        MeetingFormMap meetingFormMap = new MeetingFormMap();
        meetingFormMap.put("id", meeting_id);
        meetingFormMap = meetingMapper.findById(meetingFormMap);
        if (!"3".equals(meetingFormMap.getStr("status"))) {// 会议未结束
            if (StringUtils.isBlank(ticket)) {// 二维码未生成过
                MeetingPermanentQrcodeFormMap lastestOutOfDataMeetingPermanentQrcode = meetingPermanentQrcodeMapper.selectLastestOutOfDataMeetingPermanentQrcode(1L);
                if (lastestOutOfDataMeetingPermanentQrcode == null) {// 没有待被占用的永久二维码记录
                    String sceneId = "14" + meeting_id;// 14开头+会议id,二维码参数唯一
                    Map map5 = WXService.createQrcodeQrLimitScene(sceneId);
                    String ecode = URLEncoder.encode(map5.get("ticket").toString());
                    MeetingPermanentQrcodeFormMap saveMap = new MeetingPermanentQrcodeFormMap();
                    // type + sceneId 确定一条永久二维码记录
                    saveMap.put("meeting_id", meeting_id);
                    saveMap.put("type", 1L);
                    saveMap.put("ticket", ecode);
                    saveMap.put("scene_id", sceneId);
                    saveMap.put("create_time", new Date().getTime());
                    baseComponentService.addEntity(saveMap);
                    model.addAttribute("ticket", ecode);
                } else {// 有待被占用的永久二维码记录，更新meeting_id
                    lastestOutOfDataMeetingPermanentQrcode.put("meeting_id", meeting_id);
                    model.addAttribute("ticket", lastestOutOfDataMeetingPermanentQrcode.getStr("ticket"));
                    baseComponentService.editEntity(lastestOutOfDataMeetingPermanentQrcode);
                }
            } else {// 二维码生成过，不再重新生成
                model.addAttribute("ticket", ticket);
            }
        } else {// 会议结束
            if (StringUtils.isBlank(ticket)) {// 二维码被占用
                model.addAttribute("ticket", null);
            } else {// 二维码未被占用
                model.addAttribute("ticket", ticket);
            }
        }
    } catch (Exception e) {
        log.error(e.getMessage());
    }
}

2.4 JSP

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<img height="400" alt="会议已结束，二维码已被其他会议占用" src="https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=${ticket}">

2.5 扫码后台响应事件

if ("14".equals(top)) {// 会议报名
    MeetingPermanentQrcodeFormMap meetingPermanentQrcodeFormMap = new MeetingPermanentQrcodeFormMap();
    // type + sceneId 确定一条永久二维码记录
    meetingPermanentQrcodeFormMap.put("scene_id", sceneId);
    meetingPermanentQrcodeFormMap.put("type", 1L);
    meetingPermanentQrcodeFormMap = meetingPermanentQrcodeMapper
            .selectMeetingPermanentQrcodeBy(meetingPermanentQrcodeFormMap);
    String meeting_id = meetingPermanentQrcodeFormMap.getStr("meeting_id");
    String url = "http://" + propertiesUtil.getProperty("wx.domain")
            + "/meetingregistration/wxRegistrationPage.shtml?meeting_id=" + meeting_id;
    String content = "您已成功获取报名链接，您可以点击<a href='" + url + "'>会议报名进行会议报名，谢谢！";
    String str = MessageUtil.constructTextMessageXml(toUserName, fromUserName, content);
    response.getWriter().println(str == null ? "" : str.toString());
    System.out.println(str);
    return;
}