微信退款---服务端

微信退款比较容易按照DEMO进行操作。

　　首先去下载微信安全证书，里面有微信安全证书使用说明：

　　　　微信支付API共四份（证书pkcs12格式、证书pem格式、证书密钥pem格式、CA证书）,为接口中强制要求时需携带的证书文件。

　　　　退款接口只需要使用 证书pkcs12格式（apiclient_cert.p12）

　　第二：查看微信申请退款接口可以看出退款传参同样需要进行签名验证，以xml的形式传送

代码如下：

 /**
     * 
     * @方法名称:payRefund
     * @内容摘要: ＜退款＞
     * @param transaction_id
     *            微信支付订单号
     * @param out_refund_no
     *            商户退款订单号
     * @param total_fee
     *            总金额
     * @param refund_fee
     *            退款金额
     * @param op_user_id
     *            操作人
     * @return String
     */
    public String wxPayRefundRequest(Order order ,String transaction_id) throws Exception{
        String strResponse = "";
        
        KeyStore keyStore  = KeyStore.getInstance("PKCS12");
        　

　　　　 // 读取微信安全证书

　　　　 String file_s = Thread.currentThread().getContextClassLoader().getResource("").toString();

　　　　 FileInputStream instream = new FileInputStream(new File(file_s.substring(5)+"/com/conf/apiclient_cert.p12"));

        try {
            keyStore.load(instream, Constant.mchID.toCharArray());
        } finally {
            instream.close();
        }

        // Trust own CA and all self-signed certs
        SSLContext sslcontext = SSLContexts.custom()
                .loadKeyMaterial(keyStore, Constant.mchID.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 {
　　　　　　　//设置访问地址，也可以用GET方式  
　　　　　　  //退款接口地址：refund_url=https://api.mch.weixin.qq.com/secapi/pay/refund
            HttpPost httpPost = new HttpPost(Constant.refund_url);
            
            Double amount = elandOrder.getOrderAmount().doubleValue();
            String oAmount = new TenPayManager().moneyToFen(amount);
//            oAmount = "1";
            
            String nonce_str = new TenPayManager().createNonceStr();
            
            String stringA = "appid=" + Constant.appID + "&mch_id=" + Constant.mchID 
                    + "&nonce_str=" + nonce_str + "&op_user_id=" +Constant.mchID  
                    + "&out_refund_no="    + order.getOrderSn().toString() + "&out_trade_no=" + Order.getOrderSn().toString() 
                    + "&refund_fee=" + oAmount + "&total_fee=" + oAmount;
            
            String stringSignTemp = stringA + "&key=" + Constant.key;
            System.out.println(stringA);
            System.out.println(stringSignTemp);
            
            // 签名最后全部转为大写
            String sign = MD5Weixin.MD5Encode(stringSignTemp).toUpperCase();
            System.out.println(sign);
            
            StringBuffer xml = new StringBuffer();
            xml.append("<xml>");
            xml.append("<appid>").append(Constant.appID).append("</appid>");
            xml.append("<mch_id>").append(Constant.mchID).append("</mch_id>");
            xml.append("<nonce_str>").append(nonce_str).append("</nonce_str>");
            xml.append("<op_user_id>").append(Constant.mchID).append("</op_user_id>");
            xml.append("<out_refund_no>").append(order.getOrderSn().toString()).append("</out_refund_no>");
            xml.append("<out_trade_no>").append(order.getOrderSn().toString()).append("</out_trade_no>");
            xml.append("<refund_fee>").append(oAmount).append("</refund_fee>");
            xml.append("<total_fee>").append(oAmount).append("</total_fee>");
            xml.append("<transaction_id>").append("").append("</transaction_id>");
            xml.append("<sign><![CDATA[").append(sign).append("]]></sign>");
            xml.append("</xml>");
            
            StringEntity se = new StringEntity(xml.toString());
            httpPost.setEntity(se);
            
            logger.info("‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’‘’executing request" + httpPost.getRequestLine());

            CloseableHttpResponse response = httpclient.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();

                logger.info("------------------------------------response.getStatusLine():"+response.getStatusLine());
                if (entity != null) {
                    System.out.println("Response content length: " + entity.getContentLength());
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent()));
                    String text = "";
                    String retXmlStr = "";
                    while ((text = bufferedReader.readLine()) != null) {
                        System.out.println(text);
                        retXmlStr = retXmlStr + text;
                        logger.info("‘’‘’‘’‘’‘’-----------------text:"+text);
                    }
                    logger.info("‘’‘’‘’‘’‘’-----------------retXmlStr:"+retXmlStr);
                    if (!"".equals(retXmlStr)) {
　　　　　　　　　　　　　　//解析xml为MAP
                        Map<String,Object> resultMap = XmlParser.xmlStrParser(retXmlStr);
                        strResponse = resultMap.get("return_code").toString();
                        logger.info("---weixin Message-code:" + resultMap.get("return_code").toString());
                        logger.info("---weixin Message:" + resultMap.get("return_msg").toString());
                    }
                   
                }
                EntityUtils.consume(entity);
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
        
        return strResponse;
    }