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./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：

2.在需要调用摄像头页面，引入JS文件

<script src="<%=request.getContextPath()%>/staticfile/js/jquery.min.js"></script><script src="http://res./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 }"/>

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： ?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./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./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>

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./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;}