JAVA 微信公众号调用摄像头并上传图片至服务器

一、主体思想

1.使用微信JS-SDK工具包。
点击button，调用拍照接口【chooseImage】和上传图片接口【uploadImage】，拿到图片的服务器端ID，即【mediaId】
2.调用【获取临时素材】接口（参数mediaId），拿到返回的流，保存到服务器。

官方文档：https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1455784140&token=&lang=zh_CN

二、实现步骤（为了整体性，部分复制文档）

1.绑定域名
先登录微信公众平台进入“公众号设置”的“功能设置”里填写“JS接口安全域名”。
例如：blog.csdn.net

2.在需要调用摄像头页面，引入JS文件

<!-- jquery 非必须 --><script src="<%=request.getContextPath()%>/staticfile/js/jquery.min.js"></script><script src="http://res.wx.qq.com/open/js/jweixin-1.2.0.js"></script>

3.通过config接口注入权限验证配置

<input type="hidden" id="appId" value="${appId }"/><input type="hidden" id="timestamp" value="${timestamp }"/><input type="hidden" id="nonceStr" value="${nonceStr }"/><input type="hidden" id="signature" value="${signature }"/>

<script>$(function(){    wx.config({        debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。        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，见附录1        jsApiList: ['chooseImage', 'uploadImage'] // 必填，需要使用的JS接口列表，所有JS接口列表见附录2    });});</script>

4.JS-SDK使用权限签名算法，生成第三步中 config接口 所需参数
注意：java代码使用jfinal3.1框架，使用到的缓存插件、参数获取等语法不一致，自适应相应修改。

获取access_token（官方：有效期7200秒，开发者必须在自己的服务全局缓存access_token）、jsapi_ticket、签名sign

import org.slf4j.Logger;import org.slf4j.LoggerFactory;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONObject;

public class XXX{    private static final Logger log = LoggerFactory.getLogger(XXX.class);    private static final String JSAPI_TICKET_CACHE = "jsapiTicketCache";    private static final String JSAPI_TICKET_CACHE_KEY = "jsapi_ticket";    private static final String ACCESS_TOKEN_CACHE = "accessTokenCache";    private static final String ACCESS_TOKEN_CACHE_KEY = "access_token";    /**    * 获取config接口 所需参数     */    public void index() {        /**        * 以下5行代码，是拼接 访问该方法的参数列表。        *        * 生成签名sign时，参数url必须是完整的。        * 例如： http://blog.csdn.net?a=1&b=2        */        //request.getParameterMap();        Map paramMap = getParaMap();        String paramUrl = "";        if (!paramMap.isEmpty() && paramMap != null) {            paramUrl = getParamsStr(paramMap);        }        log.info("paramUrl-->{}", paramUrl);        /**         * 1、获取jsapi_ticket         */        String jsapi_ticket = CacheKit.get(JSAPI_TICKET_CACHE, JSAPI_TICKET_CACHE_KEY);        if (StrKit.isBlank(jsapi_ticket)) {            String access_token = getAccessToken();            log.info("access_token-->{}", access_token);            jsapi_ticket = getJsapiTicket(access_token);            CacheKit.put(JSAPI_TICKET_CACHE, JSAPI_TICKET_CACHE_KEY, jsapi_ticket);        }        log.info("jsapi_ticket-->{}", jsapi_ticket);        /**         * 2、生成签名         */        SortedMap<Object, Object> params = new TreeMap<Object, Object>();        String noncestr = WeixinSignUtil.getNonceStr();        String timestamp = WeixinSignUtil.getTimestamp();        params.put("noncestr", noncestr);        params.put("jsapi_ticket", jsapi_ticket);        params.put("timestamp", timestamp);        if (StrKit.isBlank(paramUrl)) {            params.put("url", AppConsts.JSSDKURL);        } else {            params.put("url", AppConsts.JSSDKURL + "?" + paramUrl);        }        String sign = WeixinSignUtil.createSignBySha1(params);        log.info("sign-->{}", sign);        setAttr("appId", AppConsts.APPID);        setAttr("timestamp", timestamp);        setAttr("nonceStr", noncestr);        setAttr("signature", sign);        render("jsp/index.jsp");    }    private String getParamsStr(Map paramMap) {        StringBuffer sb = new StringBuffer();        Set set = paramMap.entrySet();        Iterator it = set.iterator();        while (it.hasNext()) {            Map.Entry entry = (Map.Entry) it.next();            String k = (String) entry.getKey();            String[] v = (String[]) entry.getValue();            for (String s : v) {                sb.append(k + "=" + s + "&");            }        }        return sb.toString().substring(0, sb.toString().length() - 1);    }    private String getAccessToken() {        String access_token = CacheKit.get(ACCESS_TOKEN_CACHE, ACCESS_TOKEN_CACHE_KEY);        if (StrKit.isBlank(access_token)) {            String url = "https://api.weixin.qq.com/cgi-bin/token";            String params = "grant_type=client_credential&appid=" + AppConsts.APPID + "&secret=" + AppConsts.APPSECRET;            //http GET方式爬虫            String result = HttpURLContent.sendGet(url, params);            JSONObject jo = JSON.parseObject(result);            access_token = jo.getString("access_token");            CacheKit.put(ACCESS_TOKEN_CACHE, ACCESS_TOKEN_CACHE_KEY, access_token);        }        return access_token;    }    private String getJsapiTicket(String access_token) {        String url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket";        String params = "access_token=" + access_token + "&type=jsapi";        String result = HttpURLContent.sendGet(url, params);        JSONObject jo = JSON.parseObject(result);        return jo.getString("ticket");    }}

WeixinSignUtil.java

package org.cold.util;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Iterator;import java.util.Map;import java.util.Set;import java.util.SortedMap;/** * 微信签名工具类 * @author cold * */public class WeixinSignUtil {    @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 Sha1.getSha1(result);    }    /**     * 获取时间戳(秒)     */    public static String getTimestamp() {        return String.valueOf(System.currentTimeMillis() / 1000);    }    /**      * 取出一个指定长度大小的随机正整数.      * @param length      *            int 设定所取出随机数的长度。length小于11      * @return int 返回生成的随机数。      */      public static int buildRandom(int length) {          int num = 1;          double random = Math.random();          if (random < 0.1) {              random = random + 0.1;          }          for (int i = 0; i < length; i++) {              num = num * 10;          }          return (int) ((random * num));      }      /**      * 获取当前时间 yyyyMMddHHmmss      */      public static String getCurrTime() {          Date now = new Date();          SimpleDateFormat outFormat = new SimpleDateFormat("yyyyMMddHHmmss");          String s = outFormat.format(now);          return s;      }      /**     * 生成随机字符串     */     public static String getNonceStr() {        String currTime = getCurrTime();          String strTime = currTime.substring(8, currTime.length());          String strRandom = buildRandom(4) + "";          return strTime + strRandom;    }}

5.调用摄像头，获取 mediaId

<button onclick="takePicture()">拍照</button>

<script>function takePicture(){    wx.chooseImage({        count: 1, // 默认9        sizeType: ['original', 'compressed'], // 可以指定是原图还是压缩图，默认二者都有        sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有        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(), // 需要上传的图片的本地ID，由chooseImage接口获得                isShowProgressTips: 1, // 默认为1，显示进度提示                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("<%=request.getContextPath()%>/savePicture",{mediaId:mediaId},function(res){                        if(res.t == 'success'){                        }else{                            alert(res.msg)                        }                    })                },                fail: function (res) {                    alertModal('上传图片失败，请重试')                }            });         }    });}</script>

6.后台接受参数mediaId，保存图片至服务器

public void savePicture() {        // request.getParameter("mediaId")        String mediaId = getPara("mediaId", "");        //保存图片 路径  PathKit.getWebRootPath() + "/vehicleupload/" + filename;        String filename = saveImageToDisk(mediaId);        setAttr("t", "success");        renderJson();}/** * 获取临时素材 */private InputStream getMedia(String mediaId) {    String url = "https://api.weixin.qq.com/cgi-bin/media/get";    String access_token = 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;}/** * 保存图片至服务器  * @param mediaId * @return 文件名 */public String saveImageToDisk(String mediaId){    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 = PathKit.getWebRootPath() + "/vehicleupload/";        filename = System.currentTimeMillis() + WeixinSignUtil.getNonceStr() + ".jpg";        fileOutputStream = new FileOutputStream(path + filename);        while ((len = inputStream.read(data)) != -1) {            fileOutputStream.write(data, 0, len);        }    } 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;}