需要：支付宝商户号，微信商户号，银联商户号

支付宝

1. 进入支付宝开放平台，我用的公钥证书方式，参考文档… 把需要的6个文件弄到，
   2.弄到文件后，后台yml配置文件中配置支付宝的一些参数和路径：
   
   3.Controller 那边接收参数传给Service就行 自己写吧
   4.Service:

  //pom.xml引入支付宝sdk
 <dependency> 
      <groupId>com.alipay.sdk</groupId>
      <artifactId>alipay-sdk-java</artifactId>
      <version>4.8.62.ALL</version>
 </dependency>
 =====================================================================================
 //支付
  public String Alipay(FinalParma finalParma,int isMobile) {
      try{CertAlipayRequest certAlipayRequest = new CertAlipayRequest();
          certAlipayRequest.setServerUrl(gaturl);
          certAlipayRequest.setAppId(appid);
          certAlipayRequest.setPrivateKey(app_private_key);
          certAlipayRequest.setFormat("json");
          certAlipayRequest.setCharset(charset);
          certAlipayRequest.setSignType(sign_type);
          certAlipayRequest.setCertPath(app_cert_path);
          certAlipayRequest.setAlipayPublicCertPath(ali_cert_path);
          certAlipayRequest.setRootCertPath(ali_root_cert_path);
          AlipayClient alipayClient = new DefaultAlipayClient(certAlipayRequest);
          if(isMobile==1){
              AlipayTradeWapPayRequest request = new AlipayTradeWapPayRequest();
              request.setReturnUrl(ali_return_url); //前台通知地址
              request.setNotifyUrl(natapp + ali_notify_url); //异步地址
              request.setBizContent(GsonUtil.getgson().toJson(finalParma));//这个就不解释了
              AlipayTradeWapPayResponse response = alipayClient.pageExecute(request);
              if(response.isSuccess()){
                  System.out.println("调用手机支付成功");
                  return response.getBody();  //返回的是html文本
              }else {
                  System.out.println("调用手机支付失败");
              }
          }else {
              AlipayTradePagePayRequest request = new AlipayTradePagePayRequest();
              request.setReturnUrl(ali_return_url);
              request.setNotifyUrl(natapp + ali_notify_url);
              request.setBizContent(GsonUtil.getgson().toJson(finalParma));
              AlipayTradePagePayResponse response = alipayClient.pageExecute(request);
              if(response.isSuccess()){
                  System.out.println("调用电脑支付成功");
                  return response.getBody();
              }else {
                  System.out.println("调用电脑支付失败");
              }
          }
      }catch (Exception e){
          e.printStackTrace();
      }
      return null;
  }

  //异步通知
  public String ali_notify(HttpServletRequest request){
      try{Map<String, String> params = new HashMap<>();
          Map requestParams = request.getParameterMap();
          for (Object o : requestParams.keySet()) {
              String name = (String) o;
              String[] values = (String[]) requestParams.get(name);
              String valueStr = "";
              for (int i = 0; i < values.length; i++) {
                  valueStr = (i == values.length - 1) ? valueStr + values[i] : valueStr + values[i] + ",";
              }
              params.put(name, valueStr);
          }
          
          boolean signVerified = AlipaySignature.rsaCertCheckV1(params, ali_cert_path, charset,sign_type);
          if(!signVerified) {
              System.out.println("校验失败");
              return "fail";
          }

          String trade_status = params.get("trade_status");
          String order_ids = URLDecoder.decode(params.get("passback_params"), "UTF-8"); //传过来的业务参数
          if (trade_status.equals("TRADE_SUCCESS")){
              System.out.println("支付成功："+trade_status);
              //业务逻辑...
              return "success";
          }
      }catch (Exception e){
          e.printStackTrace();
      }
      return "fail";
  }

  //退款
  public String ali_refund(Order order){
      try{CertAlipayRequest certAlipayRequest = new CertAlipayRequest();
          certAlipayRequest.setServerUrl(gaturl);
          certAlipayRequest.setAppId(appid);
          certAlipayRequest.setPrivateKey(app_private_key);
          certAlipayRequest.setFormat("json");
          certAlipayRequest.setCharset(charset);
          certAlipayRequest.setSignType(sign_type);
          certAlipayRequest.setCertPath(app_cert_path);
          certAlipayRequest.setAlipayPublicCertPath(ali_cert_path);
          certAlipayRequest.setRootCertPath(ali_root_cert_path);
          AlipayClient alipayClient = new DefaultAlipayClient(certAlipayRequest);
          AlipayTradeRefundRequest request = new AlipayTradeRefundRequest();

          RefundPar refundPar = new RefundPar();
          refundPar.setOut_trade_no(order.getOut_trade_no());
          refundPar.setTrade_no(order.getTrade_no());
          refundPar.setOut_request_no(order.getOrder_sn());
          refundPar.setRefund_amount(order.getPay_amount());
          request.setBizContent(GsonUtil.getgson().toJson(refundPar));
          AlipayTradeRefundResponse response = alipayClient.certificateExecute(request);

          if(response.isSuccess()){
              System.out.println("调用退款成功");
              //业务逻辑
              return response.getBody();
          } else {
              System.out.println("调用退款失败");
          }
      }catch (Exception e){
          e.printStackTrace();
      }
      return null;
  }
======================================================================================
 //支付宝同步跳转接口
 @RequestMapping("/ali_return_url")
 public String ali_return_url(HttpServletRequest request){
     return "<html>\n" +
           "<head>\n" +
           "</head>\n" +
           "<body>\n" +
           "<div style=\"display: flex\">\n" +
           "    <b style=\"margin: 100px auto;color: red;font-size: 50px;\"> 支付成功："+request.getParameter("total_amount") +"元 </b>\n" +
           "</div>\n" +
           "</body>\n" +
           "</html>";
 }
 //支付宝基本接口ok.拿去即用

微信

1.搞到微信需要的一些证书文件后，yml配置：

2.再来一个配置类：

3.Controller自己写， Service：

     <!--pom.xml文件引入微信sdk-->
     <dependency>
         <groupId>com.github.wxpay</groupId>
         <artifactId>wxpay-sdk</artifactId>
         <version>0.0.3</version>
     </dependency>
  =============================================================================
  
    @Resource
    WxPayAppConfig myWXPayConfig;

    //wx支付
    public String WeChat(FinalParma finalParma){
        Map<String, String> returnMap = new HashMap<>();
        Map<String, String> responseMap = new HashMap<>();
        Map<String, String> requestMap = new HashMap<>();
        try {
            WXPay wxpay = new WXPay(myWXPayConfig);
            requestMap.put("body", finalParma.getSubject());                        // 商品描述
            requestMap.put("out_trade_no", "1415659990");                           // 商户订单号
            requestMap.put("total_fee", "855");                                     // 总金额
            requestMap.put("spbill_create_ip", "123.123.123.123");                  // 终端IP
            requestMap.put("trade_type", "NATIVE");                                 // 支付类型
            requestMap.put("notify_url", myWXPayConfig.getWx_notify_url());         // 接收微信支付异步通知回调地址

            Map<String, String> resultMap = wxpay.unifiedOrder(requestMap);
            System.out.println(resultMap);

            String returnCode = resultMap.get("return_code");
            String returnMsg = resultMap.get("return_msg");
            if ("SUCCESS".equals(returnCode)) {
                String resultCode = resultMap.get("result_code");
                String errCodeDes = resultMap.get("err_code_des");
                if ("SUCCESS".equals(resultCode)) {
                    responseMap = resultMap;
                }
            }
            if (responseMap.isEmpty()) {
                System.out.println("结果为空");
                return "结果为空";
            }
            // 3、签名生成算法
            Long time = System.currentTimeMillis() / 1000;
            String timestamp = time.toString();
            returnMap.put("appid", myWXPayConfig.getAppID());
            returnMap.put("partnerid", myWXPayConfig.getMchID());
            returnMap.put("prepayid", responseMap.get("prepay_id"));
            returnMap.put("noncestr", responseMap.get("nonce_str"));
            returnMap.put("timestamp", timestamp);
            returnMap.put("package", "Sign=WXPay");
            returnMap.put("sign", WXPayUtil.generateSignature(returnMap, myWXPayConfig.getKey())); //微信支付签名

            System.out.println("调用微信支付成功");
            return "ok";
        } catch (Exception e) {
            e.printStackTrace();
            return "微信支付统一下单异常";
        }

    }
    //异步通知
    public String wx_notify(String notifyStr) {
        String xmlBack = "<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[报文为空]]></return_msg></xml> ";
        try {
            // 转换成map
            Map<String, String> resultMap = WXPayUtil.xmlToMap(notifyStr);
            WXPay wxpayApp = new WXPay(myWXPayConfig);
            if (wxpayApp.isPayResultNotifySignatureValid(resultMap)) {
                String returnCode = resultMap.get("return_code");  //状态
                String outTradeNo = resultMap.get("out_trade_no");//商户订单号
                String transactionId = resultMap.get("transaction_id");
                if (returnCode.equals("SUCCESS")) {
                    if (StringUtils.isNotBlank(outTradeNo)) {
                        System.out.println("成功");
                        xmlBack = "<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>";
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return xmlBack;
    }

    //退款
    public String wx_refund(Order order){
        Map<String, String> responseMap = new HashMap<>();
        Map<String, String> requestMap = new HashMap<>();
        WXPay wxpay = new WXPay(myWXPayConfig);
//        requestMap.put("out_trade_no", orderNo);
//        requestMap.put("out_refund_no", UUIDGenerator.getOrderNo());
//        requestMap.put("total_fee", "订单支付时的总金额，需要从数据库查");
//        requestMap.put("refund_fee", String.valueOf((int)(amount*100)));//所需退款金额
//        requestMap.put("refund_desc", refundReason);
        try {
            responseMap = wxpay.refund(requestMap);
        } catch (Exception e) {
            e.printStackTrace();
        }
        String return_code = responseMap.get("return_code");   //返回状态码
        String return_msg = responseMap.get("return_msg");     //返回信息
        if ("SUCCESS".equals(return_code)) {
            String result_code = responseMap.get("result_code");       //业务结果
            String err_code_des = responseMap.get("err_code_des");     //错误代码描述
            if ("SUCCESS".equals(result_code)) {
                //表示退款申请接受成功，结果通过退款查询接口查询
                return "退款申请成功";
            } else {
                return "错误";
            }
        } else {
            return "错误";
        }
    }

=====================================================================================
    //微信异步接口
    @RequestMapping("/wx_notify_url")
    public String wx_notify_url(HttpServletRequest request){
        System.out.println("微信异步通知");
        InputStream is = null;
        String xmlBack = "<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[报文为空]]></return_msg></xml> ";
        try {
            is = request.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            xmlBack = service_weChat.wx_notify(sb.toString());
        } catch (Exception e) {
            System.out.println("微信手机支付回调通知失败");
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return xmlBack;
    }
OK

银联

1.打开银联开发平台，找到开发包 下载：

解压找到这几个文件，配置文件就拷贝到项目里，配置一下证书文件的路径就可以：
3.拷贝开发包中的sdk, 把sdk里面的所有类搞到项目里:

4.再把demo文件里面的这个类搞到项目里，改个名，我改成UnionpayBese：

5.再搞一个类：

@Component
public class InitUnionPayProject implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        SDKConfig.getConfig().loadPropertiesFromSrc();
    }
}

6.一共有这些东西：

7.Service：

    //银联支付
    public String UnionPay(FinalParma finalParma,int isMobile){
        try
        {
            Map<String, String> requestData = new HashMap<String, String>();
            requestData.put("version", UnionpayBese.version);
            requestData.put("encoding", UnionpayBese.encoding);            //字符集编码
            requestData.put("signMethod", SDKConfig.getConfig().getSignMethod());
            requestData.put("txnType", "01");                             //交易类型 ，01：消费
            requestData.put("txnSubType", "01");                          //交易子类型， 01：自助消费
            requestData.put("bizType", "000201");                         //业务类型，B2C网关支付，手机wap支付
            requestData.put("frontUrl", frontUrl);   //前台跳转地址
            requestData.put("backUrl", natapp + backUrl);  //异步通知地址

            requestData.put("merId", merID);
            requestData.put("accessType", "0");
            System.out.println("订单号：" +finalParma.getOut_trade_no());
            requestData.put("orderId", finalParma.getOut_trade_no());
            requestData.put("txnTime", TimeUtils.getDate("yyyyMMddHHmmss"));
            requestData.put("currencyCode", "156");
            requestData.put("txnAmt", changeBranch(finalParma.getTotal_amount()));
            if(isMobile==1){
                System.out.println("手机网页");
                requestData.put("channelType", "08");
            }else{
                System.out.println("pc网页");
                requestData.put("channelType", "07");
            }
            requestData.put("reqReserved", finalParma.getPassback_params()); //穿透域，传业务参数
            requestData.put("riskRateInfo", "{commodityName="+finalParma.getSubject()+"}"); 
            Map<String, String> submitFromData = AcpService.sign(requestData, UnionpayBese.encoding);
            String requestFrontUrl = SDKConfig.getConfig().getFrontRequestUrl();
            String html = AcpService.createAutoFormHtml(requestFrontUrl, submitFromData, UnionpayBese.encoding);
            return html;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

    //元转分
    String changeBranch(String amount) {
        String currency = amount.replaceAll("\\$|\\￥|\\,", "");
        int index = currency.indexOf(".");
        int length = currency.length();
        Long amLong;
        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();
    }

    //银联异步通知
    public boolean unionpay_notify(HttpServletRequest request){
        try{
            String encoding = request.getParameter(SDKConstants.param_encoding);
            Map<String, String> reqParam = new HashMap<String, String>();
            Enumeration<?> temp = request.getParameterNames();
            if (null != temp) {
                while (temp.hasMoreElements()) {
                    String en = (String) temp.nextElement();
                    String value = request.getParameter(en);
                    reqParam.put(en, value);
                    if (reqParam.get(en) == null || "".equals(reqParam.get(en))) {
                        reqParam.remove(en);
                    }
                }
            }
            Map<String, String> valideData = null;
            if (null != reqParam && !reqParam.isEmpty()) {
                Iterator<Map.Entry<String, String>> it = reqParam.entrySet().iterator();
                valideData = new HashMap<String, String>(reqParam.size());
                while (it.hasNext()) {
                    Map.Entry<String, String> e = it.next();
                    String key = (String) e.getKey();
                    String value = (String) e.getValue();
                    valideData.put(key, value);
                }
            }

            if (!AcpService.validate(valideData, encoding)) {
                System.out.println("验签失败,需解决验签问题！");
            } else {
                String order_ids = valideData.get("reqReserved");
                String[] idArr = order_ids.split(",");
                List<Order> orders = service_order.GetOrder(idArr,"","");
                for (Order order: orders){
                    if(order.getStatus()==0){ //如果没支付，就处理业务逻辑
//                        order.setOut_trade_no(valideData.get("orderId"));
//                        order.setTrade_no(valideData.get("queryId"));  queryId这个比较重要
                    }
                }
                return true;
            }
        }catch (Exception e){
            e.printStackTrace();
            return false;
        }
        return false;
    }

    //银联退款
    public String unionpay_refund(Order order){
        Map<String, String> data = new HashMap<String, String>();
        data.put("version", UnionpayBese.version);
        data.put("encoding", UnionpayBese.encoding);         //字符集编码 可以使用UTF-8,GBK两种方式
        data.put("signMethod", SDKConfig.getConfig().getSignMethod()); //签名方法
        data.put("txnType", "04");                           //交易类型 04-退货
        data.put("txnSubType", "00");                        //交易子类型  默认00
        data.put("bizType", "000301");                       //业务类型 B2C网关支付，手机wap支付
        data.put("channelType", "07");                       //渠道类型，07-PC，08-手机
        data.put("merId", merID);
        data.put("accessType", "0");
        data.put("orderId", "T"+order.getOut_trade_no()); //不能一样哦
        data.put("txnTime", TimeUtils.getDate("yyyyMMddHHmmss"));
        data.put("currencyCode", "156");
        data.put("txnAmt", changeBranch(order.getPay_amount().toString()));
        data.put("backUrl", "http://www.specialUrl.com"); //不需要通知
        data.put("origQryId", order.getTrade_no());
        
        Map<String, String> reqData  = AcpService.sign(data,UnionpayBese.encoding);
        Map<String, String> rspData = AcpService.post(reqData,SDKConfig.getConfig().getBackRequestUrl(),UnionpayBese.encoding);
        
        try{
            System.out.println("rspData: "+ rspData);
            if (AcpService.validate(rspData, UnionpayBese.encoding)) {
                String respCode = rspData.get("respCode");
                if ("00".equals(respCode)) {
                	//.....
                    return "退款成功";
                }
            }
        }catch (Exception e){
            e.printStackTrace();
            return null;
        }
        return null;

// 分转元：
String y = request.getParameter("txnAmt");
BigDecimal.valueOf(Long.valueOf(y)).divide(new BigDecimal(100)).toString();

三个支付基本集成了, 测试可以正式就改改就可以，银联的最麻烦
银联有个坑，异步通知会发长报文过来，要停止异步通知只能回应200，但会先回应100，导致无限异步通知, 没想到解决方法

VUE

打开后台传的html文本就可以支付了


借鉴了一些文章，感谢各位前辈