微信公众号开发调用摄像头、拍摄或选择图片、OCR识别

 一 、准备工作      

<1> 域名认证准备工作

在需要调用摄像头的接口页面引入微信的js，具体地址为：（支持https）：http://res.wx.qq.com/open/js/jweixin-1.2.0.js

首先JS安全接口域名认证：

具体可参考开发文档：https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421141115
    填写规则（必须是备案通过的域名）：
    若域名类似为：xxx.xxx.xxx.com　   则接口域名为：xxx.xxx.com
    若域名类似为：xxx.xxx.com      则接口域名为：xxx.com
    若域名类似为：xxx.xxx.com:8080   则接口域名为：xxx.com:8080
   <2> OCR识别准备工作

注册百度云服务账号，网址：https://cloud.baidu.com/index.html?track=cp:npinzhuan|pf:pc|pp:left|ci:|pu:495
    点击智能控制台>>产品服务>>人工智能>>文字识别>>创建应用
    填写相关信息选择对应的需求
    点击创建应用>>查看详情：appid、apikey、secretkey是我们所需要的
  

二、具体代码实现

在需要调用微信js的jsp页面引入js，做如下操作：

 $(function (){
     wx.config({
         debug: true, // 开启调试模式,调用的所有api的返回值会在客户端alert出来,测试完成后需要关闭。
         appId: $('#appId').val(), // 必填，公众号的唯一标识
         timestamp: $('#timestamp').val(), // 必填，生成签名的时间戳
         nonceStr: $('#nonceStr').val(), // 必填，生成签名的随机串
         signature: $('#signature').val(),// 必填，签名（加密后，下文有实现）
         jsApiList: ['chooseImage', 'uploadImage'] // 必填，需要使用的JS接口列表，开发文档上有所有接口名称，根据需要选用就好。
     });
 });

 function openCamera(){
     wx.chooseImage({
         count: 1, // 默认9
         sizeType: ['original', 'compressed'], // 指定是原图还是压缩图，默认都有
         sourceType: ['album', 'camera'], // 指定来源是相册还是相机，默认都有
         success: function (res) {
             var localIds = res.localIds; // 返回选定照片的本地ID列表，localId可以作为img标签的src属性显示图片
             wx.uploadImage({
                 localId: localIds.toString(), // 需要上传的图片的ID，由chooseImage接口获得
                 isShowProgressTips: 1, // 进度提示
                 success: function (res) {
                     var mediaId = res.serverId; // 返回图片的服务器端ID，即mediaId
                     //将获取到的 mediaId 传入后台 方法savePicture
                     $.post(path+"/getImage/savePicture",{"mediaId":mediaId,"tmp":"填写证件的正反面参数"},function(res){
                         //填写你自己的业务逻辑
                     });
                 },
                 fail: function (res) {
                     alertModal('图片上传失败，请重试');
                 }
             });
         }
     });
 }

wx.config这个函数是进行js域名验证所必须的操作，具体实现如下：

 //-------------------------初始化js-sdk--------begin----------------------------
         SortedMap<Object, Object> params = new TreeMap<Object, Object>();
         String access_token = WechatAppUtil.getAccessToken(appid,appSecret);// 建议放redis放缓存中（access_token ）
         String jsapi_ticket = WechatAppUtil.getJsapiTicket(access_token);
         String noncestr = WechatSignUtil.getNonceStr();
         String timestamp = WechatSignUtil.getTimestamp();
         params.put("noncestr", noncestr);
         params.put("jsapi_ticket", jsapi_ticket);
         params.put("timestamp", timestamp);
         StringBuffer url = cRequest.getRequestURL();
         Enumeration<String> headerNames = cRequest.getHeaderNames();
             if (headerNames != null) {
                 while (headerNames.hasMoreElements()) {
                     String header = headerNames.nextElement();
                     log.info("Header: {}， Value={}", header, cRequest.getHeader(header));
                 }
             }
             String httpFlag = cRequest.getHeader("X-Forwarded-Proto");
             if (httpFlag != null && httpFlag.equals("https")) {
                 url.replace(0, 5, "https");
             }
             String queryString = cRequest.getQueryString();
             log.info("queryString={}", queryString);
             if (StringUtil.isNotEmpty(queryString)) {
                 url.append("?").append(cRequest.getQueryString());
             }
         params.put("url", url.toString());
         log.info("url---------------->:"+url.toString());
         String sign = WechatSignUtil.createSignBySha1(params);
         log.info("sign---------------->:"+sign);
         //-------------------------初始化js-sdk--------end----------------------------
         ModelAndView tView = new ModelAndView(LoginPageConstant.STAFF_REGIST2);
         tView.addObject("appId", appid);
         tView.addObject("timestamp", timestamp);
         tView.addObject("nonceStr", noncestr);
         tView.addObject("signature", sign); return tView; 

 /**
     * @Title: getAccessToken
     * @Description: 获取公众号access_token
     * @param @param appId
     * @param @param appSecret
     * @param @return
     * @return String    返回类型
     * @throws
     */
     public static String getAccessToken(String appId,String appSecret){
         final String param = "grant_type=client_credential" + "&appid=" + appId + "&secret=" + appSecret;
         final String data = HttpClientUtil.get(GET_ACCESS_TOKEN_PATH, param);
         JSONObject resultJson = JSON.parseObject(data);
         String access_token = resultJson.getString("access_token");
         return access_token;
     }

     /**
      *
     * @Title: getJsapiTicket
     * @Description: 获取JsapiTicket
     * @param @param access_token
     * @param @return
     * @return String    返回类型
     * @throws
      */
     public static String getJsapiTicket(String access_token){
         final String param = "access_token="+access_token+ "&type=jsapi";
         final String data = HttpClientUtil.get(GET_JSAPI_TICKET, param);
         JSONObject resultJson = JSON.parseObject(data);
         String jsapi_ticket = resultJson.getString("ticket");
         return jsapi_ticket;
     }/**
      *
     * @Title: getNonceStr
     * @Description: 生成随机字符串
     * @param @return
     * @return String    返回类型
     * @throws
      */
     public static String getNonceStr() {
         String currT = getCurrTime();
         String strT = currT.substring(8, currT.length());
         String strRandom = buildRandom(4) + "";
         return strT + strRandom;
     }

     /**
      *
     * @Title: buildRandom
     * @Description: 生成随机数
     * @param @param length
     * @param @return
     * @return int    返回类型
     * @throws
      */
     public static int buildRandom(int length) {
         int mm= 1;
         double random = Math.random();
         if (random < 0.1) {
             random = random + 0.1;
         }
         for (int i = 0; i < length; i++) {
             mm= mm* 10;
         }
         return (int) ((random * mm));
     }

     /**
      *
     * @Title: getCurrTime
     * @Description: 获取当前时间
     * @param @return
     * @return String    返回类型
     * @throws
      */
      public static String getCurrTime() {
             Date date = new Date();
             SimpleDateFormat of= new SimpleDateFormat("yyyyMMddHHmmss");
             String s = of.format(date);
             return s;
      } 

     /**
      *
     * @Title: createSignBySha1
     * @Description: 生成签名
     * @param @param params
     * @param @return
     * @return String    返回类型
     * @throws
      */
     @SuppressWarnings("rawtypes")
     public static String createSignBySha1(SortedMap<Object, Object> params) {
         StringBuffer sb = new StringBuffer();
         Set es = params.entrySet();
         Iterator it = es.iterator();
         while (it.hasNext()) {
             Map.Entry entry = (Map.Entry) it.next();
             String k = (String) entry.getKey();
             String v = (String) entry.getValue();
             if (v != null && !v.equals("")) {
                 sb.append(k + "=" + v + "&");
             }
         }
         String result = sb.toString().substring(0, sb.toString().length()-1);
         return getSHA1(result);
     }
     /**
      *
     * @Title: getTimestamp
     * @Description: 获取时间戳(秒)
     * @param @return    参数
     * @return String    返回类型
     * @throws
      */
     public static String getTimestamp() {
         return String.valueOf(System.currentTimeMillis() / 1000);
         }

     /**
      *
     * @Title: getSHA1
     * @Description: SHA1签名生成
     * @param @param str
     * @param @return    参数
     * @return String    返回类型
     * @throws
      */
      public static String getSHA1(String str){
         StringBuffer hexstr = new StringBuffer();
         try {
             MessageDigest md = MessageDigest.getInstance("SHA-1");
             md.update(str.getBytes());
                 byte[] digest = md.digest();
                 String shaHex = "";
                 for (int i = 0; i < digest.length; i++) {
                     shaHex = Integer.toHexString(digest[i] & 0xFF);
                     if (shaHex.length() < 2) {
                         hexstr.append(0);
                     }
                     hexstr.append(shaHex);
                 }
         } catch (NoSuchAlgorithmException e) {
             e.printStackTrace();
         }
         return hexstr.toString();
     }

验证完成后台实现如下：

 /**
      *
     * @Title: savePicture
     * @Description: 接收图片
     * @param @param request
     * @param @return
     * @return String    返回类型
     * @throws
      */
     @ResponseBody
     @RequestMapping("/savePicture")
     public String savePicture(HttpServletRequest request) {
         String mediaId = request.getParameter("mediaId");
         String tmp = request.getParameter("tmp");
         String filename = saveImageToDisk(mediaId,tmp,request);
         log.info("filename----------->:"+filename);
         return "success";
     }

     /**
      *
     * @Title: saveImageToDisk
     * @Description: 存盘
     * @param @param mediaId
     * @param @return
     * @return String    返回类型
     * @throws
      */
     private String saveImageToDisk(String mediaId,String tmp,HttpServletRequest request){
         String filename = "";
         InputStream inputStream = getMedia(mediaId);
         byte[] data = new byte[1024];
         int len = 0;
         FileOutputStream fileOutputStream = null;
         try {
             //服务器存图路径
             String path = request.getServletContext().getRealPath("你需要存放的服务器路径");
             filename = System.currentTimeMillis() + WechatSignUtil.getNonceStr() + ".jpg";
             fileOutputStream = new FileOutputStream(path + filename);
             while ((len = inputStream.read(data)) != -1) {
                 fileOutputStream.write(data, 0, len);
             }
             WeChatUser idCardMsg = getIdCardMsg(tmp,path + filename);
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             if (inputStream != null) {
                 try {
                     inputStream.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
             if (fileOutputStream != null) {
                 try {
                     fileOutputStream.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         }
         return filename;
     }

     /**
      *
     * @Title: getMedia
     * @Description: 获取图片
     * @param @param mediaId
     * @param @return    参数
     * @return InputStream    返回类型
     * @throws
      */
     private InputStream getMedia(String mediaId) {
         String url = "https://api.weixin.qq.com/cgi-bin/media/get";
         String access_token = WechatAppUtil.getAccessToken("**********","*************");
         String params = "access_token=" + access_token + "&media_id=" + mediaId;
            InputStream is = null;
            try {
             String urlNameString = url + "?" + params;
                URL urlGet = new URL(urlNameString);
                HttpURLConnection http = (HttpURLConnection) urlGet.openConnection();
                http.setRequestMethod("GET"); // 必须是get方式请求
                http.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
                http.setDoOutput(true);
                http.setDoInput(true);
                http.connect();
                // 获取文件转化为byte流
                is = http.getInputStream();
            } catch (Exception e) {
                e.printStackTrace();
            }
         return is;
     }

     /**
      *
     * @Title: getIdCardMsg
     * @Description:
     * @param @param tmp
     * @param @param imgUrl 图片路径
     * @param @return
     * @return WeChatUser    返回类型
     * @throws
      */
     private WeChatUser getIdCardMsg(String tmp,String imgUrl){
     // 初始化一个AipOcr
         AipOcr client = new AipOcr(APP_ID, API_KEY, SECRET_KEY);
     // 可选：设置网络连接参数
         client.setConnectionTimeoutInMillis(2000);
         client.setSocketTimeoutInMillis(60000);
         // 传入可选参数调用接口
     HashMap<String, String> options = new HashMap<String, String>();
     options.put("detect_direction", "true");
     options.put("detect_risk", "false");
     String idCardSide = tmp;
     // 参数为图片路径
     String image = imgUrl;
     JSONObject res = client.idcard(image, idCardSide, options);
     具体返回信息处理请参考开发文档:https://cloud.baidu.com/doc/OCR/OCR-Java-SDK.html#.E6.8E.A5.E5.8F.A3.E8.83.BD.E5.8A.9B
     }