公司做公众号时需要接入微信支付，个人根据网上的demo摸索着完成了公司公众号的支付和退款功能。现也将代码分享出来，希望对需要朋友有帮助。
一.提交支付的toPay.jsp页面代码：
<%String basePath = request.getScheme() + "://"+ request.getServerName() + request.getContextPath()+ "/";%><html><body>....<div class="zdx3"><button onclick="pay()">共需支付${sumPrice }元 确认支付</button></div></body></html> <script>function pay() {var url="<%=basePath%>wechat/pay?money=${sumPrice}"; //注意此处的basePath是没有端口号的域名地址。如果包含:80,在提交给微信时有可能会提示 “redirect_uri参数错误” 。//money为订单需要支付的金额//state中存放的为商品订单号var weixinUrl="https://open./connect/oauth2/authorize?appid=${appId}&redirect_uri="+encodeURI(url)+"&response_type=code&scope=snsapi_userinfo&state=${orderId}#wechat_redirect";window.location.href=encodeURI(weixinUrl);}</script>
二.后台处理支付功能代码
（包含两部分:
1.处理支付信息，通过微信接口生成订单号，返回支付页面
2.提供一个微信支付完成后的回调接口）
第1部分代码：
/*** 用户提交支付，获取微信支付订单接口*/@RequestMapping(value="/pay")public ModelAndView pay(HttpServletRequest request,HttpServletResponse response){ModelAndView mv = new ModelAndView();String GZHID = "wxfd7c065eee11112222";// 微信公众号idString GZHSecret = "b5b3a627f5d1f8888888888888";// 微信公众号密钥idString SHHID = "111111111";// 财付通商户号String SHHKEY = "mmmmmmmmmmmmmmm";// 商户号对应的密钥/*------1.获取参数信息------- *///商户订单号String out_trade_no= request.getParameter("state"); //价格String money = request.getParameter("money");//金额转化为分为单位String finalmoney = WeChat.getMoney(money);//获取用户的codeString code = request.getParameter("code");/*------2.根据code获取微信用户的openId和access_token------- *///注： 如果后台程序之前已经得到了用户的openId 可以不需要这一步，直接从存放openId的位置或session中获取就可以。//toPay.jsp页面中提交的url路径也就不需要再经过微信重定向。写成：http://localhost:8080/项目名/wechat/pay?money=${sumPrice}&state=${orderId}String openid=null;try {List<Object> list = accessToken(code);openid=list.get(1).toString();} catch (IOException e) {logger.error("根据code获取微信用户的openId出现错误", e);mv.setViewName("error");return mv;}/*------3.生成预支付订单需要的的package数据------- *///随机数 String nonce_str= MD5.getMessageDigest(String.valueOf(new Random().nextInt(10000)).getBytes());//订单生成的机器 IPString spbill_create_ip = request.getRemoteAddr();//交易类型 ：jsapi代表微信公众号支付String trade_type = "JSAPI";//这里notify_url是 微信处理完支付后的回调的应用系统接口url。String notify_url ="http://69a6a38e./heyi-console/wechat/weixinNotify";SortedMap<String, String> packageParams = new TreeMap<String, String>();packageParams.put("appid", GZHID); packageParams.put("mch_id", SHHID); packageParams.put("nonce_str", nonce_str); packageParams.put("body", "费用"); packageParams.put("out_trade_no", out_trade_no); packageParams.put("total_fee", finalmoney); packageParams.put("spbill_create_ip", spbill_create_ip); packageParams.put("notify_url", notify_url); packageParams.put("trade_type", trade_type); packageParams.put("openid", openid); /*------4.根据package数据生成预支付订单号的签名sign------- */RequestHandler reqHandler = new RequestHandler(request, response);reqHandler.init( GZHID, GZHSecret, SHHKEY);String sign = reqHandler.createSign(packageParams);/*------5.生成需要提交给统一支付接口https://api.mch./pay/unifiedorder 的xml数据-------*/String xml="<xml>"+"<appid>"+ GZHID+"</appid>"+"<mch_id>"+ SHHID+"</mch_id>"+"<nonce_str>"+nonce_str+"</nonce_str>"+"<sign>"+sign+"</sign>"+"<body><![CDATA["+"费用"+"]]></body>"+"<out_trade_no>"+out_trade_no+"</out_trade_no>"+"<total_fee>"+finalmoney+"</total_fee>"+"<spbill_create_ip>"+spbill_create_ip+"</spbill_create_ip>"+"<notify_url>"+notify_url+"</notify_url>"+"<trade_type>"+trade_type+"</trade_type>"+"<openid>"+openid+"</openid>"+"</xml>";/*------6.调用统一支付接口https://api.mch./pay/unifiedorder 生产预支付订单----------*/String createOrderURL = "https://api.mch./pay/unifiedorder";String prepay_id="";try {prepay_id = GetWxOrderno.getPayNo(createOrderURL, xml);if(prepay_id.equals("")){mv.addObject("ErrorMsg", "支付错误");mv.setViewName("error");return mv;}} catch (Exception e) {logger.error("统一支付接口获取预支付订单出错", e);mv.setViewName("error");return mv;}/*将prepay_id存到库中*/PageData p = new PageData();p.put("shopId", out_trade_no);p.put("prePayId", prepay_id);activityService.updatePrePayId(p);/*------7.将预支付订单的id和其他信息生成签名并一起返回到jsp页面 ------- */nonce_str= MD5.getMessageDigest(String.valueOf(new Random().nextInt(10000)).getBytes());SortedMap<String, String> finalpackage = new TreeMap<String, String>();String timestamp = String.valueOf(System.currentTimeMillis() / 1000);String packages = "prepay_id="+prepay_id;finalpackage.put("appId", GZHID); finalpackage.put("timeStamp", timestamp); finalpackage.put("nonceStr", nonce_str); finalpackage.put("package", packages); finalpackage.put("signType", "MD5");String finalsign = reqHandler.createSign(finalpackage);mv.addObject("appid", GZHID);mv.addObject("timeStamp", timestamp);mv.addObject("nonceStr", nonce_str);mv.addObject("packageValue", packages);mv.addObject("paySign", finalsign);mv.addObject("success","ok");mv.setViewName("wechat/pay");return mv;}
第2部分代码：
/*** 提交支付后的微信异步返回接口*/@RequestMapping(value="/weixinNotify")public void weixinNotify(HttpServletRequest request, HttpServletResponse response){String out_trade_no=null;String return_code =null;try {InputStream inStream = request.getInputStream();ByteArrayOutputStream outSteam = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while ((len = inStream.read(buffer)) != -1) {outSteam.write(buffer, 0, len);}outSteam.close();inStream.close();String resultStr = new String(outSteam.toByteArray(),"utf-8");logger.info("支付成功的回调："+resultStr);Map<String, Object> resultMap = parseXmlToList(resultStr);String result_code = (String) resultMap.get("result_code");String is_subscribe = (String) resultMap.get("is_subscribe");String transaction_id = (String) resultMap.get("transaction_id");String sign = (String) resultMap.get("sign");String time_end = (String) resultMap.get("time_end");String bank_type = (String) resultMap.get("bank_type");out_trade_no = (String) resultMap.get("out_trade_no");return_code = (String) resultMap.get("return_code");request.setAttribute("out_trade_no", out_trade_no);//通知微信.异步确认成功.必写.不然微信会一直通知后台.八次之后就认为交易失败了.response.getWriter().write(RequestHandler.setXML("SUCCESS", ""));} catch (Exception e) {logger.error("微信回调接口出现错误：",e);try {response.getWriter().write(RequestHandler.setXML("FAIL", "error"));} catch (IOException e1) {e1.printStackTrace();}} if(return_code.equals("SUCCESS")){//支付成功的业务逻辑}else{//支付失败的业务逻辑}}
三.微信app中具体支付的jsp页面
<html><head><script src="js/jquery-1.8.2.min.js" type="text/javascript"></script></head><body onload="javascript:pay();"><script type="text/javascript">function pay(){if (typeof WeixinJSBridge == "undefined"){if( document.addEventListener ){document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);}else if (document.attachEvent){document.attachEvent('WeixinJSBridgeReady', onBridgeReady); document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);}}else{onBridgeReady();} }function onBridgeReady(){WeixinJSBridge.invoke('getBrandWCPayRequest', {"appId" : "${appid}",//公众号名称，由商户传入"timeStamp": "${timeStamp}", //时间戳，自1970年以来的秒数"nonceStr" : "${nonceStr}", //随机串"package" : "${packageValue}","signType" : "MD5", //微信签名方式:"paySign" : "${paySign}" //微信签名 },function(res){if(res.err_msg == "get_brand_wcpay_request:ok"){ alert("微信支付成功!");}else if(res.err_msg == "get_brand_wcpay_request:cancel"){ alert("用户取消支付!");}else{ alert("支付失败!");} }); }</script></body></html>
其他需要用到的相关类和方法：
金额 元转分：
/*** 元转换成分* @param money* @return*/public static String getMoney(String amount) {if(amount==null){return "";}// 金额转化为分为单位String currency = amount.replaceAll("\\$|\\￥|\\,", ""); //处理包含, ￥ 或者$的金额 int index = currency.indexOf("."); int length = currency.length(); Long amLong = 0l; if(index == -1){ amLong = Long.valueOf(currency+"00"); }else if(length - index >= 3){ amLong = Long.valueOf((currency.substring(0, index+3)).replace(".", "")); }else if(length - index == 2){ amLong = Long.valueOf((currency.substring(0, index+2)).replace(".", "")+0); }else{ amLong = Long.valueOf((currency.substring(0, index+1)).replace(".", "")+"00"); } return amLong.toString(); }
通过微信用户code获取用户的openId:
/*** 通过微信用户的code换取网页授权access_token* @return* @throws IOException* @throws*/public List<Object> accessToken(String code) throws IOException {List<Object> list = new ArrayList<Object>();String url = "https://api./sns/oauth2/access_token?appid="+ WeChat.HYGZHID + "&secret=" + WeChat.HYGZHSecret+ "&code=" + code + "&grant_type=authorization_code";HttpClient client = new DefaultHttpClient();HttpPost post = new HttpPost(url);HttpResponse res = client.execute(post);if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {HttpEntity entity = res.getEntity();String str = org.apache.http.util.EntityUtils.toString(entity, "utf-8");ObjectMapper mapper=new com.fasterxml.jackson.databind.ObjectMapper.ObjectMapper();Map<String,Object> jsonOb=mapper.readValue(str, Map.class);list.add(jsonOb.get("access_token"));list.add(jsonOb.get("openid"));}return list;}
MD5提取摘要：
/*** MD5加密*/public class MD5 {private MD5() {}/*** 对传入的数据提取摘要* @param buffer* @return*/public final static String getMessageDigest(byte[] buffer) {char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };try {MessageDigest mdTemp = MessageDigest.getInstance("MD5");mdTemp.update(buffer);byte[] md = mdTemp.digest();int j = md.length;char str[] = new char[j * 2];int k = 0;for (int i = 0; i < j; i++) {byte byte0 = md[i];str[k++] = hexDigits[byte0 >>> 4 & 0xf];str[k++] = hexDigits[byte0 & 0xf];}return new String(str);} catch (Exception e) {return null;}}}
解析微信回调的xml数据：
/*** description: 解析微信通知xml* * @param xml* @return* @author ex_yangxiaoyi* @see*/@SuppressWarnings({ "unused", "rawtypes", "unchecked" })private static Map parseXmlToList(String xml) {Map retMap = new HashMap();try {StringReader read = new StringReader(xml);// 创建新的输入源SAX 解析器将使用 InputSource 对象来确定如何读取 XML 输入InputSource source = new InputSource(read);// 创建一个新的SAXBuilderSAXBuilder sb = new org.jdom.input.SAXBuilder.SAXBuilder();// 通过输入源构造一个DocumentDocument doc = (Document) sb.build(source);Element root = doc.getRootElement();// 指向根节点List<Element> es = root.getChildren();if (es != null && es.size() != 0) {for (Element element : es) {retMap.put(element.getName(), element.getValue());}}} catch (Exception e) {e.printStackTrace();}return retMap;}
java文件和需要用到的工具类，我都放到csdn的下载中了。
地址：/download/aofavx/10606894 (免积分)。
如果有不对或者少文件的地方，请留言。我给大家补正。
