第三方对接-支付宝支付

应用场景：

商户出售商品，用户购买支付，商户接入第三方支付平台支付宝

对接要求：

1、先创建网页&移动应用点击打开链接，提交并且通过审核后才能进行对接

2、开发者调用接口前需要先生成RSA2密钥，RSA密钥包含应用私钥(APP_PRIVATE_KEY)、应用公钥(APP_PUBLIC_KEY）。生成密钥后在开放平台管理中心进行密钥配置，配置完成后可以获取支付宝公钥(ALIPAY_PUBLIC_KEY) 

3、搭建和配置开发环境

下载服务端SDK：

    com.alipay.sdk
    alipay-sdk-java
    3.0.0

对接流程：

1、封装参数，申请接入支付宝支付，会有APPID，公钥私钥等参数。

2、支付流程

1. 1. 发起一个支付请求（携带订单号，价格等参数）到支付宝统一下单接口，生成预支付路径，响应给客户端浏览器。
   2. 用户进行扫码或者在页面登录支付宝支付。
   3. 服务端异步接收支付结果。

①：发起支付请求

@RequestMapping("gotoPay")
public void gotoPay(HttpServletRequest httpRequest,HttpServletResponse httpResponse) throws ServletException, IOException {
    AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do", APP_ID, APP_PRIVATE_KEY, FORMAT, CHARSET, ALIPAY_PUBLIC_KEY, SIGN_TYPE); //获得初始化的AlipayClient
    AlipayTradePagePayRequest alipayRequest = new AlipayTradePagePayRequest();//创建API对应的request
    alipayRequest.setReturnUrl("http://domain.com/CallBack/returnURL.html");//回跳地址
    alipayRequest.setNotifyUrl("http://domain.com/CallBack/notifyURL.html");//通知地址
    alipayRequest.setBizContent("{" +
        " \"out_trade_no\":\"20150320010101001\"," +                                        //订单号（支付宝要求商户订单号必须唯一）
        " \"product_code\":\"FAST_INSTANT_TRADE_PAY\"," +                                   //销售产品码，与支付宝签约的产品码名称，目前仅支持FAST_INSTANT_TRADE_PAY。
        " \"total_amount\":88.88," +                                                        //价格
        " \"subject\":\"Iphone6 16G\"," +                                                   //订单标题
        " \"body\":\"Iphone6 16G\"," +                                                      //订单描述
        " \"passback_params\":\"merchantBizType%3d3C%26merchantBizNo%3d2016010101111\"," +  //公用回传参数，如果请求时传递了该参数，则返回给商户时会回传该参数。支付宝只会在异步通知时将该参数原样返回。本参数必须进行UrlEncode之后才可以发送给支付宝
        " \"extend_params\":{" +                                                            //业务扩展参数
        " \"sys_service_provider_id\":\"2088511833207846\"" +                                //系统商编号，该参数作为系统商返佣数据提取的依据，请填写系统商签约协议的PID
        " }"+
        " }");//填充业务参数
    String form="";
    try {
        form = alipayClient.pageExecute(alipayRequest).getBody(); //调用SDK生成表单
    } catch (AlipayApiException e) {
        e.printStackTrace();
    }
    httpResponse.setContentType("text/html;charset=" + CHARSET);
    httpResponse.getWriter().write(form);//直接将完整的表单html输出到页面
    httpResponse.getWriter().flush();
    httpResponse.getWriter().close();
}

②、用户确认支付后，支付宝get请求returnUrl(将网页重定向到何处)

@RequestMapping(value = "returnURL", method = RequestMethod.GET)
public String returnURL(Device device) {
    System.out.println("支付宝处理完毕后返回商户网站");
    if (device.isNormal()) {
        return "shop/alipay/payResult";
    } else {
        return "mobile/alipay/payResult";
    }
}

③、交易成功后，支付宝post请求notifyUrl

@RequestMapping(value = "notifyURL", method = RequestMethod.POST)
public void notifyURL(HttpServletRequest httpRequest){
    //将异步通知中收到的所有参数都存放到map中 ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
    Map paramsMap = MapUtil.map();
		Map requestParams = request.getParameterMap();
    for (Object element : requestParams.keySet()) {
        String name = (String) element;
        String[] values = requestParams.get(name);
        StringBuilder valueStr = new StringBuilder();
        for (int i = 0; i < values.length; i++) {
            valueStr.append((i == values.length - 1) ? values[i] : values[i] + ",");
        }
        params.put(name, valueStr.toString());
    }
    //将异步通知中收到的所有参数都存放到map中 ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
   
    boolean signVerified = AlipaySignature.rsaCheckV1(paramsMap, ALIPAY_PUBLIC_KEY, CHARSET, SIGN_TYPE) //调用SDK验证签名
    if(signVerfied){
        // TODO 验签成功后，按照支付结果异步通知中的描述，对支付结果中的业务内容进行二次校验，校验成功后在response中返回success并继续商户自身业务处理，校验失败返回failure
    }else{
        // TODO 验签失败则记录异常日志，并在response中返回failure.
    }
}

④、若由于网络等问题异步通知没有到达，商户可自行调用alipay.trade.query接口进行查询，根据查询接口获取交易以及支付信息（商户也可以直接调用查询接口，不需要依赖异步通知）。

public void query(){
    AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do","app_id","your private_key","json","GBK","alipay_public_key","RSA2");
    AlipayTradeQueryRequest request = new AlipayTradeQueryRequest();
    request.setBizContent("{" +
        "\"out_trade_no\":\"20150320010101001\"," +                        //订单支付时传入的商户订单号,和支付宝交易号不能同时为空。 
        "\"trade_no\":\"2014112611001004680 073956707\"" +                 //支付宝交易号，和商户订单号不能同时为空
        "  }");
    AlipayTradeQueryResponse response = alipayClient.execute(request);
    if(response.isSuccess()){
        //获取支付信息
        System.out.println("调用成功");
    } else {
        System.out.println("调用失败");
    }
}

⑤、交易发生后一段时间内，如果用户想退款，买家可以通过退款接口将支付款退给买家。

public void refund() throws AlipayApiException {
        AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do","app_id","your private_key","json","GBK","alipay_public_key","RSA2");
        AlipayTradeRefundRequest request = new AlipayTradeRefundRequest();
        request.setBizContent("{" +
            "\"out_trade_no\":\"20150320010101001\"," + 
            "\"trade_no\":\"2014112611001004680073956707\"," +
            "\"refund_amount\":200.12," +
            "\"refund_currency\":\"USD\"," +
            "\"refund_reason\":\"正常退款\"," +
            "\"out_request_no\":\"HZ01RF001\"," +
            "\"operator_id\":\"OP001\"," +
            "\"store_id\":\"NJ_S_001\"," +
            "\"terminal_id\":\"NJ_T_001\"," +
            "      \"goods_detail\":[{" +
            "        \"goods_id\":\"apple-01\"," +
            "\"alipay_goods_id\":\"20010001\"," +
            "\"goods_name\":\"ipad\"," +
            "\"quantity\":1," +
            "\"price\":2000," +
            "\"goods_category\":\"34543238\"," +
            "\"body\":\"特价手机\"," +
            "\"show_url\":\"http://www.alipay.com/xxx.jpg\"" +
            "        }]" +
            "  }");
        AlipayTradeRefundResponse response = alipayClient.execute(request);
        if(response.isSuccess()){
            System.out.println("调用成功");
        } else {
            System.out.println("调用失败");
        }
}

⑥、统一收单交易退款查询

public void queryRefund(){
    AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do","app_id","your private_key","json","GBK","alipay_public_key","RSA2");
    AlipayTradeFastpayRefundQueryRequest request = new AlipayTradeFastpayRefundQueryRequest();
    request.setBizContent("{" +
       "\"trade_no\":\"20150320010101001\"," +
       "\"out_trade_no\":\"2014112611001004680073956707\"," +
       "\"out_request_no\":\"2014112611001004680073956707\"" +
       "  }");
    AlipayTradeFastpayRefundQueryResponse response = alipayClient.execute(request);
    if(response.isSuccess()){
        System.out.println("调用成功");
    } else {
        System.out.println("调用失败");
    }
}

⑦、统一收单交易关闭接口(用于交易创建后，用户在一定时间内未进行支付，可调用该接口直接将未付款的交易进行关闭。)

public void tradeClose(){
    AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do","app_id","your private_key","json","GBK","alipay_public_key","RSA2");
    AlipayTradeRefundRequest request = new AlipayTradeRefundRequest();
    request.setBizContent("{" +
        "\"out_trade_no\":\"20150320010101001\"," +
        "\"trade_no\":\"2014112611001004680073956707\"," +
        "\"refund_amount\":200.12," +
        "\"refund_currency\":\"USD\"," +
        "\"refund_reason\":\"正常退款\"," +
        "\"out_request_no\":\"HZ01RF001\"," +
        "\"operator_id\":\"OP001\"," +
        "\"store_id\":\"NJ_S_001\"," +
        "\"terminal_id\":\"NJ_T_001\"," +
        "      \"goods_detail\":[{" +
        "        \"goods_id\":\"apple-01\"," +
        "\"alipay_goods_id\":\"20010001\"," +
        "\"goods_name\":\"ipad\"," +
        "\"quantity\":1," +
        "\"price\":2000," +
        "\"goods_category\":\"34543238\"," +
        "\"body\":\"特价手机\"," +
        "\"show_url\":\"http://www.alipay.com/xxx.jpg\"" +
        "        }]" +
        "  }");
    AlipayTradeRefundResponse response = alipayClient.execute(request);
    if(response.isSuccess()){
        System.out.println("调用成功");
    } else {
        System.out.println("调用失败");
    }
}

真心话，支付宝对接的API比微信写的强太多了 支付宝官方API