本章文献基本都来源于微信支付平台，详情请看微信官方文档：APP支付
文档位置：https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_3 APP支付-业务流程
根据文档内容，服务端只要做好获取 prepay_id 和 sign 传送给客户端，并做好回调接收处理就行
APP支付文档里面的demo，主要是供客户端使用的，对后台来说，基本没什么用。
不过，依旧有我们后端可以直接拿来使用的demo： https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=11_1
这个demo主要用于付款码/扫码/H5支付使用，但里面提供了很多方便的工具类。
这里我们引用demo里面的工具类并继承WXPayConfig和实现IWXPayDomain的抽象接口。
public class WxPayConfigImpl extends WXPayConfig{
// 设置应用Id
public static String appid = "2019102168481752";
// 设置商户号
public static String mch_id = "1230000109";
// 设置设备号（终端设备号(门店号或收银设备ID)，默认请传"WEB"，非必需）
public static String device_info = "WEB";
// 设置字符集
public static String key = "192006250b4c09247ec02edce69f6a2d";
private static WxPayConfigImpl INSTANCE;
public static WxPayConfigImpl getInstance() throws Exception {
if (INSTANCE == null) {
synchronized (WxPayConfigImpl.class) {
if (INSTANCE == null) {
INSTANCE = new WxPayConfigImpl();
}
}
}
return INSTANCE;
}
@Override
public String getAppID() {
return appid;
}
@Override
public String getMchID() {
return mch_id;
}
@Override
public String getKey() {
return key;
}
@Override
public InputStream getCertStream() {
//这个可以看我另一篇“支付宝：APP支付接口2.0(alipay.trade.app.pay)”
//里的“使用demo”步骤，有讲解，如果是个springboot构成的jar，如何设置证书路径
//文章链接：https://blog.csdn.net/u014799292/article/details/102680149
String fileUrl = "证书路径";
InputStream certStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(fileUrl);
byte[] certData = null;
try {
certData = IOUtils.toByteArray(certStream);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(certStream != null){
try {
certStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return new ByteArrayInputStream(certData);
}
@Override
public IWXPayDomain getWXPayDomain() {
return WxPayDomainImpl.instance();
}
}
public class WxPayDomainImpl implements IWXPayDomain {
private final int MIN_SWITCH_PRIMARY_MSEC = 3 * 60 * 1000; //3 minutes
private long switchToAlternateDomainTime = 0;
private Map<String, DomainStatics> domainData = new HashMap<String, DomainStatics>();
private WxPayDomainImpl(){
}
private static class WxpayDomainHolder{
private static IWXPayDomain holder = new WxPayDomainImpl();
}
public static IWXPayDomain instance(){
return WxpayDomainHolder.holder;
}
@Override
public void report(String domain, long elapsedTimeMillis, Exception ex) {
DomainStatics info = domainData.get(domain);
if(info == null){
info = new DomainStatics(domain);
domainData.put(domain, info);
}
if(ex == null){ //success
if(info.succCount >= 2){ //continue succ, clear error count
info.connectTimeoutCount = info.dnsErrorCount = info.otherErrorCount = 0;
}else{
++info.succCount;
}
}else if(ex instanceof ConnectTimeoutException){
info.succCount = info.dnsErrorCount = 0;
++info.connectTimeoutCount;
}else if(ex instanceof UnknownHostException){
info.succCount = 0;
++info.dnsErrorCount;
}else{
info.succCount = 0;
++info.otherErrorCount;
}
}
@Override
public DomainInfo getDomain(WXPayConfig config) {
DomainStatics primaryDomain = domainData.get(WXPayConstants.DOMAIN_API);
if(primaryDomain == null ||
primaryDomain.isGood()) {
return new DomainInfo(WXPayConstants.DOMAIN_API, true);
}
long now = System.currentTimeMillis();
if(switchToAlternateDomainTime == 0){ //first switch
switchToAlternateDomainTime = now;
return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
}else if(now - switchToAlternateDomainTime < MIN_SWITCH_PRIMARY_MSEC){
DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
if(alternateDomain == null ||
alternateDomain.isGood() ||
alternateDomain.badCount() < primaryDomain.badCount()){
return new DomainInfo(WXPayConstants.DOMAIN_API2, false);
}else{
return new DomainInfo(WXPayConstants.DOMAIN_API, true);
}
}else{ //force switch back
switchToAlternateDomainTime = 0;
primaryDomain.resetCount();
DomainStatics alternateDomain = domainData.get(WXPayConstants.DOMAIN_API2);
if(alternateDomain != null)
alternateDomain.resetCount();
return new DomainInfo(WXPayConstants.DOMAIN_API, true);
}
}
static class DomainStatics {
final String domain;
int succCount = 0;
int connectTimeoutCount = 0;
int dnsErrorCount =0;
int otherErrorCount = 0;
DomainStatics(String domain) {
this.domain = domain;
}
void resetCount(){
succCount = connectTimeoutCount = dnsErrorCount = otherErrorCount = 0;
}
boolean isGood(){ return connectTimeoutCount <= 2 && dnsErrorCount <= 2; }
int badCount(){
return connectTimeoutCount + dnsErrorCount * 5 + otherErrorCount / 4;
}
}
}
给 WXPayUtil 再添加几个时间工具方法（看自己需求定制），项目会在最后附链接。
登录商户平台-产品中心-账号关联（AppID绑定），进入授权申请页面；
登录商户平台-->>账户中心-->>API安全-->>设置API密钥（32位，下面给出生成方式，然后复制粘贴到秘钥位置，记得保留，之后无法查看，只能再次生成，测试环境随便改，正式服记得最好固定一次，修改可能会引起服务端数据错误）
private static final String SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
private static final Random RANDOM = new SecureRandom();
/**
* 获取随机字符串 Nonce Str
*
* @return String 随机字符串
*/
public static String generateNonceStr() {
char[] nonceChars = new char[32];
for (int index = 0; index < nonceChars.length; ++index) {
nonceChars[index] = SYMBOLS.charAt(RANDOM.nextInt(SYMBOLS.length()));
}
return new String(nonceChars);
}
再来写一个请求类，处理微信订单（订单--统一下单/调起支付接口/支付结果通知/查询订单/关闭订单）
/**
* 订单--统一下单/调起支付接口/退款/结果通知/查询订单/关闭订单
* 借鉴：https://blog.csdn.net/asd54090/article/details/81028323
*/
public class WxAppPayRequest {
private static final Logger logger = LoggerFactory.getLogger(WxAppPayRequest.class);
private WxPayConfigImpl config;
private WXPay wxpay;
/**
* 微信支付请求
*/
public WxAppPayRequest() {
try {
config = WxPayConfigImpl.getInstance();
wxpay = new WXPay(config);
} catch (Exception e) {
e.printStackTrace();
logger.error("微信配置初始化错误", e);
}
}
/**
* APP支付订单请求
*
* @param body
* 格式：APP名字-实际商品名称，如：天天爱消除-游戏充值
* @param attach
* 附加数据，在查询API和支付通知中原样返回
* @param outTradeNo
* 商户订单号
* @param totalFee
* 总金额
* @param startTime
* 订单开始时间String格式： yyyy-MM-dd HH:mm:ss
* @param expireMinute
* 有效时间（分钟）
* @param notifyUrl
* 微信支付异步通知回调地址
* @return
*/
private WxAppPayResponseCode getOrderSign(String body, String attach, String outTradeNo, BigDecimal totalFee,
String startTime, int expireMinute, String notifyUrl) {
// 准备好请求参数
Map<String, String> map = new HashMap<String, String>();
map.put("device_info", WxPayConfigImpl.device_info);
map.put("body", body);
if (attach != null && !attach.isEmpty()) {
map.put("attach", attach);
}
map.put("out_trade_no", outTradeNo);
map.put("total_fee", totalFee.toString());
map.put("spbill_create_ip", WXPayUtil.getLocalAddress());
map.put("time_start", WXPayUtil.getFormatTime(startTime));
String endTime = WXPayUtil.getNSecondTime(startTime, expireMinute);
map.put("time_expire", WXPayUtil.getFormatTime(endTime));
map.put("notify_url", notifyUrl);
map.put("trade_type", "APP");
// 生成带sign的xml字符串
Map<String, String> unifiedOrderMap = null;
try {
unifiedOrderMap = wxpay.unifiedOrder(map);
if (unifiedOrderMap == null || (unifiedOrderMap != null
&& WxAppPayResponseCode.FAIL.code().equals(unifiedOrderMap.get("return_code")))) {
String errorMsg = "调用微信“统一下单”获取prepayid 失败...";
logger.info("getOrderSign --unifiedOrder: 调用微信“统一下单”获取prepayid 失败.");
logger.info("getOrderSign --unifiedOrder: 请求参数：" + map.toString());
logger.info("getOrderSign --unifiedOrder: 返回Map：" + unifiedOrderMap);
if (unifiedOrderMap != null) {
errorMsg += " 异常信息为：" + unifiedOrderMap.get("return_msg");
}
WxAppPayResponseCode error = WxAppPayResponseCode.ERROR;
error.setAlias(errorMsg);
return error;
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
logger.error("getOrderSign : 调用微信“统一下单”失败 。", e);
WxAppPayResponseCode error = WxAppPayResponseCode.ERROR;
error.setAlias("调用微信“统一下单”失败 。" + e.toString());
return error;
}
// 调用微信请求成功，但响应失败
String resultCode = unifiedOrderMap.get("result_code");
if (WxAppPayResponseCode.FAIL.code().equals(resultCode)) {
WxAppPayResponseCode error = WxAppPayResponseCode.findCode(unifiedOrderMap.get("err_code"));
return error;
}
return parseWXOrderResponse(unifiedOrderMap);
}
/**
* 将map转成客户端订单用的封装体
*
* @param map
* map
* @return 用户端用的封装体
*/
private WxAppPayResponseCode parseWXOrderResponse(Map<String, String> map) {
WxOrderResponse response = new WxOrderResponse();
response.setAppid(map.get("appid"));
response.setPartnerid(map.get("partnerid"));
response.setPrepayid(map.get("prepay_id"));
response.setPack("Sign=WXPay");
response.setNoncestr(map.get("noncestr"));
String timestamp = WXPayUtil.getCurrentTimestamp() + "";
response.setTimestamp(timestamp);
// 前人踩坑，咱们乘凉
// sgin（签名），不是拿微信“统一下单”返回的sgin，而是自己再签一次，返回给客户端
// 签名的参数拿的不是“统一下单”，而是拿“调起支付接口”里面的参数，这步API文档写的是客户端生成，不过咱们服务端就帮他做了
// 注意：map的key不能是大写
Map<String, String> params = new HashMap<>();
params.put("appid", map.get("appid"));
params.put("partnerid", map.get("partnerid"));
params.put("prepayid", map.get("prepay_id"));
params.put("package", "Sign=WXPay");
params.put("noncestr", map.get("nonce_str"));
params.put("timestamp", timestamp);
try {
// 这个sign是移动端要请求微信服务端的，也是我们要保存后面校验的
String sgin = WXPayUtil.generateSignature(params, config.getKey());
response.setSign(sgin);
} catch (Exception e) {
e.printStackTrace();
logger.error("parseWXOrderResponse : 订单第二次供客户端签名信息失败 。");
logger.error("parseWXOrderResponse : 请求参数：" + params.toString());
logger.error("parseWXOrderResponse : 返回错误信息：", e);
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用支付接口生成签名sign失败！");
return errorData;
}
WxAppPayResponseCode successData = WxAppPayResponseCode.SUCCESS;
successData.setAlias(JSONObject.toJSONString(response));
return successData;
}
/**
* 查微信订单
*
* @param outTradeNo
* 订单号
*/
public WxAppPayResponseCode queryOrderByOutTradeNo(String outTradeNo) {
logger.info("查询微信支付订单信息，订单号为：" + outTradeNo);
HashMap<String, String> data = new HashMap<String, String>();
data.put("out_trade_no", outTradeNo);
try {
Map<String, String> orderQueryMap = wxpay.orderQuery(data);
return disposeReturnInfo(orderQueryMap);
} catch (Exception e) {
e.printStackTrace();
logger.error("queryOrderByOutTradeNo : 查询微信订单支付信息失败 。订单号：" + outTradeNo);
logger.error("queryOrderByOutTradeNo : 返回错误信息：", e);
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用查微信订单支付信息接口失败！");
return errorData;
}
}
/**
* 关闭订单（刚刚生成的订单不能立马关闭，要间隔5分钟，请自行做好判断）
*
* @param outTradeNo
* 订单号
* @return
*/
public WxAppPayResponseCode closeOrder(String outTradeNo) {
logger.info("关闭微信支付订单信息，订单号为：" + outTradeNo);
HashMap<String, String> data = new HashMap<>();
data.put("out_trade_no", outTradeNo);
try {
Map<String, String> closeOrderMap = wxpay.closeOrder(data);
return disposeReturnInfo(closeOrderMap);
} catch (Exception e) {
e.printStackTrace();
logger.error("closeOrder : 微信关闭订单失败 。订单号：" + outTradeNo);
logger.error("closeOrder : 返回错误信息：", e);
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用查微信订单支付信息接口失败！");
return errorData;
}
}
/**
* 微信退款申请
*
* @param outTradeNo
* 商户订单号
* @param amount
* 金额
* @param refund_desc
* 退款原因（可空）
* @param notifyUrl
* 退款异步通知链接
*
* @return 返回map（已做过签名验证），具体数据参见微信退款API
*/
public WxAppPayResponseCode refundOrder(String outTradeNo, BigDecimal amount, String refundDesc, String notifyUrl)
throws Exception {
Map<String, String> data = new HashMap<String, String>();
data.put("out_trade_no", outTradeNo);
data.put("out_refund_no", outTradeNo);
data.put("total_fee", amount + "");
data.put("refund_fee", amount + "");
data.put("refund_fee_type", "CNY");
data.put("refund_desc", refundDesc);
data.put("notifyUrl", notifyUrl);
try {
Map<String, String> refundOrderMap = wxpay.refund(data);
return disposeReturnInfo(refundOrderMap);
} catch (Exception e) {
e.printStackTrace();
logger.error("closeOrder : 微信退款申请失败 。订单号：" + outTradeNo);
logger.error("closeOrder : 返回错误信息：", e);
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用微信退款申请信息接口失败！");
return errorData;
}
}
/**
* 查微信退款订单 注：如果单个支付订单部分退款次数超过20次请使用退款单号查询
*
* @param outTradeNo
* 订单号
*/
public WxAppPayResponseCode queryRefundOrderByOutTradeNo(String outTradeNo) {
logger.info("查询微信支付订单信息，订单号为：" + outTradeNo);
HashMap<String, String> data = new HashMap<String, String>();
data.put("out_trade_no", outTradeNo);
try {
Map<String, String> refundQueryMap = wxpay.refundQuery(data);
return disposeReturnInfo(refundQueryMap);
} catch (Exception e) {
e.printStackTrace();
logger.error("queryRefundOrderByOutTradeNo : 查询微信退款订单信息失败 。订单号：" + outTradeNo);
logger.error("queryRefundOrderByOutTradeNo : 返回错误信息：", e);
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用查微信退款订单接口失败！");
return errorData;
}
}
/**
* 对接口接收成功后的返回进行处理
*
* @param resultMap
* @return
*/
private WxAppPayResponseCode disposeReturnInfo(Map<String, String> resultMap) {
if (resultMap == null
|| (resultMap != null && WxAppPayResponseCode.FAIL.code().equals(resultMap.get("return_code")))) {
WxAppPayResponseCode errorData = WxAppPayResponseCode.ERROR;
errorData.setAlias("调用微信接口失败！返回数据为 : " + resultMap);
return errorData;
}
if (WxAppPayResponseCode.FAIL.code().equals(resultMap.get("result_code"))) {
WxAppPayResponseCode errorData = WxAppPayResponseCode.findCode(resultMap.get("err_code"));
return errorData;
}
WxAppPayResponseCode successData = WxAppPayResponseCode.SUCCESS;
successData.setAlias(JSONObject.toJSONString(resultMap));
return successData;
}
/**
* 是否成功接收微信支付回调 用于回复微信，否则微信回默认为商户后端没有收到回调
*
* @return
*/
public String returnWXPayVerifyMsg() {
return "<xml>\n" + "\n" + " <return_code><![CDATA[SUCCESS]]></return_code>\n"
+ " <return_msg><![CDATA[OK]]></return_msg>\n" + "</xml>";
}
public static void main(String[] args) {
WxAppPayRequest pay = new WxAppPayRequest();
WxAppPayResponseCode orderSign = pay.getOrderSign("APP-商品订单支付", "data1;data2", "212458542512542542",
new BigDecimal("100.12"), "2019-01-02 23:55:14", 10, "http://XXX");
System.out.println(orderSign);
}
}
OK，基本搞定，构建成一个处理微信订单功能的JAR。
项目已推送github：https://github.com/leopardF/wxpay
最后，再次附上本次借鉴的文章：
微信APP支付-API列表
微信支付SDK与DEMO下载
微信APP支付-JAVA
如果问题，请提醒修正。
