公众号开发（四）----接收事件推送之扫描带参数二维码事件

忘是亡心i 2022-03-22 09:28 886阅读 0赞

接着前面的博客进度。如现在再把扫描带参数二维码进入公众号的用户保存到数据库

一、临时二维码：

获取二维码需要先获取ticket，再用ticket来换图片。这里请求参数比较短，就不封装对象了，直接使用字符串拼接成json串。

1、方法一、使用scene\_id获取ticket，建议使用这种方法：

（1）、先生成二维码加一张背景图的图片：

WechatUtil：

//生成临时二维码ticket scene_id json
    private static final String QRCODE_TEMPORARY_TICKET_SCENE_ID = "{\"expire_seconds\": SECONDS, \"action_name\": \"QR_SCENE\", \"action_info\": {\"scene\": {\"scene_id\": SCENEID}}}";
    	
    //生成临时二维码ticket scene_str json
    private static final String QRCODE_TEMPORARY_TICKET_SCENE_STR = "{\"expire_seconds\": SECONDS, \"action_name\": \"QR_STR_SCENE\", \"action_info\": {\"scene\": {\"scene_str\": SCENESTR}}}";
    	
    //生成临时二维码ticket 的url
    private static final String QR_TEMPORARY_TICKET_URL= "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=TOKEN";
    	
    
    
    //使用scene_id生成临时二维码ticket
    public static QrTicket getTemporaryQRTicketBySceneId(String appId, String appSecert,
    			Long expireSeconds,  Long sceneId){
    		AccessToken accessToken = getAccessToken(appId, appSecert);
    		String url = QR_TEMPORARY_TICKET_URL.replace("TOKEN", accessToken.getAccessToken());
    		String postJson = QRCODE_TEMPORARY_TICKET_SCENE_ID.replace("SECONDS", String.valueOf(expireSeconds))
    				.replace("SCENEID", String.valueOf(sceneId));
    		JSONObject res = HttpsUtil.httpRequest(url, "POST", postJson);
    		QrTicket qrTicket = new QrTicket();
    		qrTicket.setExpireSeconds((Integer) res.get("expire_seconds"));
    		qrTicket.setTicket(res.getString("ticket"));
    		qrTicket.setUrl("url");
    		return qrTicket;
    	}
    
    
    
    
    
    /**
         * 将二维码和背景图片拼装成新的分享图片
         * @param shareImageUrl 分享背景图片的地址
         * @param qrCodeUrl 二维码图片的地址
         * @param content 文字内容
         * @return base64 String 的图片
         */
        public static String getQrImgUrl(String shareImageUrl, String qrCodeUrl, String content) {
            try {
                // 读取背景图片
                BufferedImage bgImage = ImageIO.read(new URL(shareImageUrl));
                // 读取二维码图片
                BufferedImage qrCodeImage = ImageIO.read(new URL(qrCodeUrl));
    
                // 创建一张原始图片
                BufferedImage bgPicture = new BufferedImage(bgImage.getWidth(null), bgImage.getHeight(null), BufferedImage.TYPE_INT_RGB);
    
                // 开启画图
                Graphics2D g = bgPicture.createGraphics();
                // 绘制背景图片
                g.drawImage(bgImage, 0, 0, null);
                // 设置目标重叠的混合处理方式和透明度
                g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 1));
                // 580*790
                int starX = bgImage.getWidth(null) * 45 / 580; // 二维码距背景图片X轴距离
                int startY = bgImage.getHeight(null) * 480 / 790; // 二维码距背景图片Y轴距离
                // 绘制二维码图片
                g.drawImage(qrCodeImage, starX, startY, 124, 124, null);
                // 绘制文字
    //            g.setColor(new Color(139,142,147));
    //            g.setFont(new Font("微软雅黑", Font.PLAIN, 18));
    //            g.drawString(content, starX, startY + 124 + 30);
                g.dispose();
    
                // 将合成的图片转为base64String
                ByteArrayOutputStream compositeImageByte = new ByteArrayOutputStream();
                ImageIO.write(bgPicture, "png", compositeImageByte);
                //转换成base64串
                String pngBase64 =  new BASE64Encoder().encodeBuffer(compositeImageByte.toByteArray()).trim();
                pngBase64 = "data:image/png;base64," + pngBase64.replaceAll("\n", "").replaceAll("\r", "");
    
                System.out.println("create base64 image success");
                return pngBase64;
            } catch (Exception e) {
            	System.out.println("create base64 image error");
                return null;
            }
        }

controller：

package com.demo.wechat.controller;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.alibaba.fastjson.JSON;
    import com.demo.wechat.domain.Message;
    import com.demo.wechat.domain.QrTicket;
    import com.demo.wechat.util.WebUtil;
    import com.demo.wechat.util.WechatUtil;
    
    @Controller
    @RequestMapping("/index")
    public class ViewController {
    	
    	@Value(value="${app.secret}")
    	private String appSecert;
    	
    	@Value(value="${app.id}")
    	private String appId;
    
    	private Long expireSeconds = 60000000L;
    
    	private Long sceneId = 666L;
    
    	private String backImgUrl = "https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=977119715,3452693422&fm=26&gp=0.jpg";
    
    	
    	//通过ticket获取二维码
    	private static final String QR_CODE_URL ="https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=TICKET";
    		
    
    	
    	//根据scene_id生成临时二维码 返回页面
    	@GetMapping("/getQrCodeBySceneId")
    	public String goQrCodeBySceneId(){
    		return "code";
    	}	
    		
    	//根据scene_id生成临时二维码
    	@PostMapping("/getQrCodeBySceneId")
    	@ResponseBody
    	public String getQrCodeBySceneId(){
    		QrTicket qrTicket = WechatUtil.getTemporaryQRTicketBySceneId(appId, appSecert, expireSeconds, 
    				 sceneId);
    		String qrCodeUrl = QR_CODE_URL.replace("TICKET", qrTicket.getTicket());  
    		String url = WechatUtil.getQrImgUrl(backImgUrl, qrCodeUrl, "扫描关注");
    		System.out.println("结果"+url);
    		return url;
    	}
    }

前端：

applcation.properties设置：

#返回的前缀   目录对应src/main/webapp下
    spring.mvc.view.prefix:/WEB-INF/view/
    #返回的后缀
    spring.mvc.view.suffix: .jsp

code.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    <script type="text/javascript" src="../assets/js/jquery-3.2.1.min.js"></script>
    <script>
    	$(function(){
    		alert("hello");
    		$.post("getQrCodeBySceneId",function(data){
    			alert(data)
    			$("#shareImage").attr('src',data); 
    		})
    	}
     )
    </script>
    </head>
    <body>
     <div id="shareBody" >
            <img id="shareImage" src="" />
            
        </div>
    </body>
    
    </html>

在浏览器访问[http://localhost:8080/wechat/index/getQrCodeBySceneId][http_localhost_8080_wechat_index_getQrCodeBySceneId]：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70][]

（2）、二维码扫描事件：

/**
    	 * 处理微信消息
    	 * @param request request
    	 * @param reqMsg 请求消息
    	 * @param respMsg 回复消息
    	 * @param remoteIp remoteIp
    	 */
    	private void handleMessage(HttpServletRequest request, WechatMsg reqMsg,  String remoteIp){
    		String type = reqMsg.getMsgType();
    		String fromUserName = reqMsg.getFromUserName();
    		String event = reqMsg.getEvent();
    		String eventKey = reqMsg.getEventKey();
    		//event事件开始
    		if(type.equals("event")){
    			//关注/取消关注公众号事件
    			WechatUser dbWechatUser = wechatUserService.getByOpenId(fromUserName);
    			if(dbWechatUser == null){
    				//还没有关注过
    				System.out.println("还没有关注过");
    				WechatUser wechatUser = new WechatUser();
    				wechatUser.setCreateTime(new Date());
    				wechatUser.setIsDelete(false);
    				wechatUser.setUpdateTime(new Date());
    				wechatUser.setUserOpenId(fromUserName);
    				
    				wechatUserService.insert(wechatUser);
    			}
    			
    			//扫描带参数二维码关注事件
    			if("subscribe".equals(event) && eventKey.startsWith("qrscene_")){
    				//去掉前缀
    				Long key = Long.valueOf(eventKey.replace("qrscene_", ""));
    				if(sceneId == key || sceneId.equals(key)){
    					System.out.println("扫描带参数二维码关注");
    					QrCodeUser dbQrCodeUser = qrCodeUserService.getByOpenId(fromUserName);
    					if(dbQrCodeUser == null){
    						//还没有记录过
    						QrCodeUser qrCodeUser = new QrCodeUser();
    						qrCodeUser.setCreateTime(new Date());
    						qrCodeUser.setIsDelete(false);
    						qrCodeUser.setOpenId(fromUserName);
    						qrCodeUser.setSceneId(String.valueOf(sceneId));
    						qrCodeUser.setUpdateTime(new Date());
    						qrCodeUserService.insert(qrCodeUser);
    					}
    				}
    			}
    			
    			//扫描带参数二维码浏览（已关注）事件
    			if("SCAN".equals(event)){
    				Long key = Long.valueOf(eventKey);
    				if(sceneId == key || sceneId.equals(key)){
    					System.out.println(fromUserName+"扫描带参数二维码已经关注");
    				}
    			}
    		}
    		//event事件结束
    	}

![20190128152729877.png][]

2、方法二、使用scene\_str获取ticket。这种方法只有在用户未关注二维码时会把str参数值带过来：

wechatUtil：

//使用scene_str生成临时二维码ticket
    public static QrTicket getTemporaryQRTicketBySceneStr(String appId, String appSecert,
    			Long expireSeconds, String sceneStr){
    		AccessToken accessToken = getAccessToken(appId, appSecert);
    		String url = QR_TEMPORARY_TICKET_URL.replace("TOKEN", accessToken.getAccessToken());
    		String postJson = QRCODE_TEMPORARY_TICKET_SCENE_STR.replace("SECONDS", String.valueOf(expireSeconds))
    				.replace("SCENESTR", sceneStr);
    		JSONObject res = HttpsUtil.httpRequest(url, "POST", postJson);
    		QrTicket qrTicket = new QrTicket();
    		qrTicket.setExpireSeconds((Integer) res.get("expire_seconds"));
    		qrTicket.setTicket(res.getString("ticket"));
    		qrTicket.setUrl("url");
    		return qrTicket;
    	}

controller:

private String scendStr = "test";
    
    //根据scene_str生成临时二维码 返回页面
    @GetMapping("/getQrCodeBySceneStr")
    	public String goQrCodeBySceneStr(){
    		return "codeStr";
    	}			
    			
    	
    //根据scene_id生成临时二维码
    @PostMapping("/getQrCodeBySceneStr")
    	@ResponseBody
    	public String getQrCodeBySceneStr(){
    		QrTicket qrTicket = WechatUtil.getTemporaryQRTicketBySceneStr(appId, appSecert,
    				expireSeconds, scendStr);
    		String qrCodeUrl = QR_CODE_URL.replace("TICKET", qrTicket.getTicket());  
    		String url = WechatUtil.getQrImgUrl(backImgUrl, qrCodeUrl, "扫描关注");
    		System.out.println("结果"+url);
    		return url;
    	}

消息：

二、永久二维码

[http_localhost_8080_wechat_index_getQrCodeBySceneId]: http://localhost:8080/wechat/index/getQrCodeBySceneId
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dfdF95X3k_size_16_color_FFFFFF_t_70]: /images/20220322/b46acbe33a2f456a827f9831a506b0ca.png
[20190128152729877.png]: /images/20220322/3a2c7e32fd994d0cb0203204f64e0016.png