公众号支付是手机端的微信公众号H5页面支付，这种支付方式必须是在微信内置浏览器发起。
扫码支付分为模式一和模式二，模式一主要为线下服务，该模式是先扫码，再生成订单，商户先为自己的商品生成二维码连接，然后用户扫码之后决定是否购买，二维码无过期时间，比如自动售卖机大多采用这种模式；模式二主要为线上电商服务，用户选择商品后生成订单，根据订单生成二维码，然后支付，该二维码为临时二维码。
开发流程
一、授权目录
官方文档说必须是精确目录，其实是二级或三级目录就可以了，太精确的可能还会出现不识别的情况。如果是扫码支付模式一还需要设置扫码支付回调URL
二.统一下单
注意传入参数不要为null，尽量不要是空字符串，如果在没有抛出Exception的情况下支付失败，十有八九是参数导致的签名有问题，微信支付的签名规定的特别严格，必须按照微信给的规则来，建议第一次先用demo提供的签名方法，以后可以再修改。这里的appid就是支付所在的公众号的appid，openId是用户对应当前公众号的openId。
1、扫码支付模式二
扫码支付比较简单，可以直接通过url发起，传入统一下单参数，生成扫码支付的url。扫码支付的trade_type为NATIVE。
public void getCodeUrl(@PathVariable(value="tradeNo")String tradeNo, HttpServletRequest request,
HttpServletResponse response) throws Exception {
//根据订单号获取订单详情
OrderProduceBean order = reservationCarService.getTradebyNo(tradeNo);
// 附加数据 原样返回
String attach = "attach";
// 总金额以分为单位，不带小数点
String totalFee = TenpayUtil.getMoney(order.getTotalFee().toString());
// 订单生成的机器 IP
String spbill_create_ip = IpUtil.getIpAddr(request);
// 这里notify_url是 支付完成后微信发给该链接信息，可以判断会员是否支付成功，改变订单状态等。
String notify_url = TenPayConfig.notifyUrl;
String trade_type = "NATIVE";
// 商户号
String mch_id = TenPayConfig.partner;
// 随机字符串
String nonce_str = TenpayUtil.getNonceStr();
// 商品描述根据情况修改
String body = order.getBody();
// 商户订单号
String out_trade_no = order.getOutTradeNo();
SortedMap<String, String> packageParams = new TreeMap<String, String>();
packageParams.put("appid", TenPayConfig.appid);
packageParams.put("mch_id", mch_id);
packageParams.put("nonce_str", nonce_str);
packageParams.put("body", body);
packageParams.put("attach", attach);
packageParams.put("out_trade_no", out_trade_no);
packageParams.put("total_fee", totalFee);
packageParams.put("spbill_create_ip", spbill_create_ip);
packageParams.put("notify_url", notify_url);
packageParams.put("trade_type", trade_type);
RequestHandler reqHandler = new RequestHandler(null, null);
reqHandler.init(TenPayConfig.appid, TenPayConfig.appsecret,
TenPayConfig.partnerkey);
String sign = reqHandler.createSign(packageParams);
String xml = "<xml>" + "<appid>" + TenPayConfig.appid + "</appid>"
+ "<mch_id>" + mch_id + "</mch_id>" + "<nonce_str>" + nonce_str
+ "</nonce_str>" + "<sign>" + sign + "</sign>"
+ "<body><![CDATA[" + body + "]]></body>" + "<out_trade_no>"
+ out_trade_no + "</out_trade_no>" + "<attach>" + attach
+ "</attach>" + "<total_fee>" + totalFee + "</total_fee>"
+ "<spbill_create_ip>" + spbill_create_ip
+ "</spbill_create_ip>" + "<notify_url>" + notify_url
+ "</notify_url>" + "<trade_type>" + trade_type
+ "</trade_type>" + "</xml>";
System.out.println(xml);
String code_url = "";
String createOrderURL = "https://api.mch.weixin.qq.com/pay/unifiedorder";
code_url = new TenPayCore().getCodeUrl(createOrderURL, xml);//调用统一下单接口
if (code_url == null || code_url.equalsIgnoreCase("")) {
logger.debug("****************************trade has closed or no this trade in tencentPay");
response.sendError(404);
return;
}
GenerateQrCodeUtil.encodeQrcode(code_url, response);
}
2.公众号支付
公众号支付首先通过H5调起支付api，微信生成订单，然后开发者获取预支付id，最后由用户确认支付。
①H5调起JSAPI。
调起有两种方式，一种是WeixinJSBridge.invoke()，另一种是最新的微信JSAPI，两种方式均可，官方文档用的第一种，使用第一种方式首先要引入http://res.wx.qq.com/open/js/jweixin-1.0.0.js。
function toPay(){
$.ajax({
url : URL,
type : "GET",
dataType : 'json',
success : function(data) {
WeixinJSBridge.invoke('getBrandWCPayRequest', {
"appId" : data.appId, //公众号名称，由商户传入
"timeStamp" : data.timeStamp, //时间戳，自1970年以来的秒数
"nonceStr" : data.nonceStr, //随机串
"package" : data.package,
"signType" : data.signType, //微信签名方式：
"paySign" : data.paySign
//微信签名
}, function(res) {
if (res.err_msg == "get_brand_wcpay_request:ok") {
} // 使用以上方式判断前端返回：res.err_msg将在用户支付成功后返回 ok，但并不保证它绝对可靠。
else{
//res.err_msg;
}
});
}
});
}
②获取预支付id
这个api和扫码支付的api差不多，就是trade为JSAPI不一样。
public void TencentPayController(@RequestParam("orderno")String orderno,HttpServletRequest request,
HttpServletResponse response) throws IOException {
//根据订单号查询订单
OrderProduceBean order=reservationCarService.getTradebyNo(orderno);
String appid = TenPayConfig.appid;
String openId =order.getOpenId();
// 订单号
String orderId = order.getOutTradeNo();
// 附加数据 原样返回
String attach = "attach";
// 总金额以分为单位，不带小数点
String totalFee = TenpayUtil.getMoney(order.getTotalFee().toString());
// 订单生成的机器 IP
String spbill_create_ip = IpUtil.getIpAddr(request);;
// 这里notify_url是 支付完成后微信发给该链接信息，可以判断会员是否支付成功，改变订单状态等。
String notify_url = TenPayConfig.notifyUrl;
String trade_type = "JSAPI";
// ---必须参数
// 商户号
String mch_id = TenPayConfig.partner;
// 随机字符串
String nonce_str = TenpayUtil.getNonceStr();
// 商品描述根据情况修改
String body = order.getBody();
// 商户订单号
String out_trade_no = orderId;
SortedMap<String, String> packageParams = new TreeMap<String, String>();
packageParams.put("appid", appid);
packageParams.put("mch_id", mch_id);
packageParams.put("nonce_str", nonce_str);
packageParams.put("body", body);
packageParams.put("attach", attach);
packageParams.put("out_trade_no", out_trade_no);
packageParams.put("total_fee", totalFee);
packageParams.put("spbill_create_ip", spbill_create_ip);
packageParams.put("notify_url", notify_url);
packageParams.put("trade_type", trade_type);
packageParams.put("openid", openId);
RequestHandler reqHandler = new RequestHandler(null, null);
reqHandler.init(appid, TenPayConfig.appsecret,TenPayConfig.partnerkey);
String sign = reqHandler.createSign(packageParams);
String xml = "<xml>" + "<appid>" + appid + "</appid>" + "<mch_id>"
+ mch_id + "</mch_id>" + "<nonce_str>" + nonce_str
+ "</nonce_str>" + "<sign>" + sign + "</sign>"
+ "<body><![CDATA[" + body + "]]></body>"
+ "<out_trade_no>" + out_trade_no
+ "</out_trade_no>" + "<attach>" + attach + "</attach>"
+ "<total_fee>" + totalFee + "</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>";
String prepay_id = "";
String createOrderURL = "https://api.mch.weixin.qq.com/pay/unifiedorder";
prepay_id = new TenPayCore().getPayNo(createOrderURL, xml);
logger.debug("********************************************");
logger.debug("prepay_id ：" + prepay_id);
//获取prepay_id后，拼接最后请求支付所需要的package
SortedMap<String, String> finalpackage = new TreeMap<String, String>();
String timestamp = Sha1Util.getTimeStamp();
String packages = "prepay_id="+prepay_id;
finalpackage.put("appId", appid);
finalpackage.put("timeStamp", timestamp);
finalpackage.put("nonceStr", nonce_str);
finalpackage.put("package", packages);
finalpackage.put("signType", "MD5");
//要签名
String finalsign = reqHandler.createSign(finalpackage);
finalpackage.put("paySign", finalsign);
String finaPackage = "\"appId\":\"" + appid + "\",\"timeStamp\":\"" + timestamp
+ "\",\"nonceStr\":\"" + nonce_str + "\",\"package\":\""
+ packages + "\",\"signType\" : \"MD5" + "\",\"paySign\":\""
+ finalsign + "\"";
logger.debug("********************************************");
logger.debug("V3 jsApi package:" + finaPackage);
if(prepay_id.length()>0){
this.callBack(response, request,this.gson.toJson(finalpackage));
return;
}else{
this.callBack(response, request,"{\"error\":\"prepay_id is null\"}");
return;
}
}
3.支付回调
该回调方法的路径就是获取预支付id中的参数notify_url,用来处理支付完成后的业务逻辑，注意一定要检查return_code和result_code是否都为success，另外一定要给微信返回success信息.
public void notifyPay(HttpServletRequest request,
HttpServletResponse response) throws IOException {
// 示例报文
String inputLine;
String notityXml = "";
String resXml = "";
try {
while ((inputLine = request.getReader().readLine()) != null) {
notityXml += inputLine;
}
request.getReader().close();
} catch (Exception e) {
e.printStackTrace();
}
Map<String, String> m = TenpayUtil.parseXmlToList(notityXml);
OrderTenPayBean orderTen = new OrderTenPayBean();
orderTen.setAppid(m.get("appid").toString());
orderTen.setBankType(m.get("bank_type").toString());
orderTen.setCashFee(m.get("cash_fee").toString());
orderTen.setFeeType(m.get("fee_type").toString());
orderTen.setIsSubscribe(m.get("is_subscribe").toString());
orderTen.setMchId(m.get("mch_id").toString());
orderTen.setNonceStr(m.get("nonce_str").toString());
orderTen.setOpenid(m.get("openid").toString());
orderTen.setOutTradeNo(m.get("out_trade_no").toString());
orderTen.setResultCode(m.get("result_code").toString());
orderTen.setReturnCode(m.get("return_code").toString());
orderTen.setSign(m.get("sign").toString());
orderTen.setTimeEnd(m.get("time_end").toString());
orderTen.setTotalFee(m.get("total_fee").toString());
orderTen.setTradeType(m.get("trade_type").toString());
orderTen.setTransactionId(m.get("transaction_id").toString());
if ("SUCCESS".equals(orderTen.getResultCode()) && "SUCCESS".equals(orderTen.getReturnCode())<span style="font-family: Arial, Helvetica, sans-serif;">) { //必须判断</span>
//TODO 信息入库，修改订单状态
// 支付成功，必须给微信返回此信息，否则微信会一直调用此回调方法
resXml = "<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>"
+ "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> ";
} else {
resXml = "<xml>" + "<return_code><![CDATA[FAIL]]></return_code>"
+ "<return_msg><![CDATA[报文为空]]></return_msg>" + "</xml> ";
}
this.callBack(response, request, resXml);
}
4.退款
退款需要把商户证书apiclient_cert.p12放到指定目录下，因为有证书的情况下退款不需要密码，一定要注意业务请求的权限问题
public void refusePay(HttpServletResponse response,HttpServletRequest request,@PathVariable(value="outTradeNo")String outTradeNo) throws Exception {
OrderProduceBean tradebyNo = reservationCarService.getTradebyNo(outTradeNo);
SortedMap<String, String> parameters = new TreeMap<String, String>();
parameters.put("appid", TenPayConfig.appid);
parameters.put("mch_id", TenPayConfig.partner);
parameters.put("nonce_str", TenpayUtil.getNonceStr());
parameters.put("out_trade_no", tradebyNo.getOutTradeNo());
parameters.put("out_refund_no", tradebyNo.getOutTradeNo()); // 我们自己设定的退款申请号，约束为UK
parameters.put("total_fee", TenpayUtil.getMoney(tradebyNo.getTotalFee().toString())); // 单位为分
parameters.put("refund_fee", TenpayUtil.getMoney(tradebyNo.getTotalFee().toString())); // 单位为分
parameters.put("op_user_id", TenPayConfig.partner);
RequestHandler reqHandler = new RequestHandler(null, null);
reqHandler.init(TenPayConfig.appid, TenPayConfig.appsecret,
TenPayConfig.partnerkey);
String sign = reqHandler.createSign(parameters);
parameters.put("sign", sign);
String reuqestXml = TenpayUtil.getRequestXml(parameters);
KeyStore keyStore = KeyStore.getInstance("PKCS12");
FileInputStream instream = new FileInputStream(new File(Resources.getString("cert_url")));
try {
keyStore.load(instream, TenPayConfig.partner.toCharArray());
} finally {
instream.close();
}
// Trust own CA and all self-signed certs
SSLContext sslcontext = SSLContexts.custom()
.loadKeyMaterial(keyStore, TenPayConfig.partner.toCharArray())
.build();
// Allow TLSv1 protocol only
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
sslcontext,
new String[] { "TLSv1" },
null,
SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
CloseableHttpClient httpclient = HttpClients.custom()
.setSSLSocketFactory(sslsf)
.build();
try {
HttpPost httpPost = new HttpPost("https://api.mch.weixin.qq.com/secapi/pay/refund");
System.out.println("executing request" + httpPost.getRequestLine());
StringEntity reqEntity = new StringEntity(reuqestXml);
// 设置类型
reqEntity.setContentType("application/x-www-form-urlencoded");
httpPost.setEntity(reqEntity);
CloseableHttpResponse reqs = httpclient.execute(httpPost);
try {
HttpEntity entity = reqs.getEntity();
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));
String returnXml = "";
String text;
while ((text = bufferedReader.readLine()) != null) {
returnXml += text;
}
//微信退款返回的参数转换为Map
Map<String, String> resultMaP = TenpayUtil.parseXmlToList(returnXml);
this.callBack(response, request, resultMaP.toString());
//TODO 信息入库
}
EntityUtils.consume(entity);
} finally {
reqs.close();
}
} finally {
httpclient.close();
}
}
PS：代码仅供参考！