SpringBoot实现微信支付统一下单
最近做小程序有需要用到微信支付，而在页面拉起微信支付前需要先进行统一下单，然后再返回参数给前端调用微信支付wx.requestPayment。网上参考了很多代码，写得都比较繁杂，所以自己写了一个比较容易理解的。下面贴上关键代码：
@Servicepublic class WxPayServiceImpl implements WxPayService{@Overridepublic Map<String, String> xcxPayment(String orderNo, BigDecimal money, int userid) {/* 准备统一下单参数 */String appid = "小程序的appID";String mch_id = "商户id";String body = "商品名称";String secretKey = "32位商户密匙";String nonce_str = getram();//获取随机字符串String out_trade_no = orderNo;//唯一订单号，根据自己业务编写BigDecimal bignum2 = new BigDecimal("100");//下单金额转换为分单位money = money.multiply(bignum2);int total_fee = money.intValue();String trade_type = "JSAPI";//小程序默认为JSAPIString notify_url = "";//接收返回数据的url，可以另写一个接口也可以随便写KUser user = userMapper.selectByPrimaryKey(userid);//获取下单用户的openidString openid = "";if(user!=null){openid = user.getOpenId();}//把参数放在map中，准备进行签名加密Map<String, String> maps = new HashMap<>();maps.put("openid", openid);maps.put("appid", appid);maps.put("mch_id", mch_id);maps.put("nonce_str", nonce_str);maps.put("body", body);maps.put("out_trade_no", out_trade_no);maps.put("total_fee", String.valueOf(total_fee));maps.put("trade_type", trade_type);maps.put("notify_url", notify_url);String spbill_create_ip = null;String sign = null;try {spbill_create_ip = getIp(); //获取本地IPmaps.put("spbill_create_ip", spbill_create_ip);sign = qianming(secretKey, maps);//进行签名加密System.out.println(sign);} catch (Exception e) {e.printStackTrace();}//拼接需要发送参数String x = "<xml>" + "<appid>" + appid + "</appid>" + "<body>" + body+ "</body>" + "<mch_id>" + mch_id + "</mch_id>" + "<nonce_str>"+ nonce_str + "</nonce_str>" + "<notify_url>" + notify_url+ "</notify_url>" + "<out_trade_no>" + out_trade_no+ "</out_trade_no>" + "<spbill_create_ip>" + spbill_create_ip+ "</spbill_create_ip>" + "<total_fee>" + total_fee+ "</total_fee>" + "<trade_type>" + trade_type+ "</trade_type>" + "<sign>" + sign + "</sign>" + "<openid>"+ openid + "</openid>" + "</xml>";/* api地址 */String url = "https://api.mch./pay/unifiedorder";Map<String, String> resultmaps = new HashMap<>();String result =null;try {x = new String(x.getBytes("UTF-8"), "ISO-8859-1");//发送统下单请求result = fasong(x, url);} catch (Exception e) {e.printStackTrace();}resultmaps = xmlStrToMap(result);//返回结果是xml字符串，转换成Map//将统一下单返回的参数进行二次签名加密if(resultmaps.get("result_code").equals("SUCCESS")&&resultmaps.get("return_code").equals("SUCCESS")){//准备二次签名加密的参数String nonceStr = getram();String package1 = "prepay_id=" + resultmaps.get("prepay_id");String timeStamp = (new Date().getTime() / 1000) + "";Map<String, String> twoMap = new HashMap<>();twoMap.put("appId", appid);twoMap.put("package", package1);twoMap.put("timeStamp", timeStamp);twoMap.put("nonceStr", nonceStr);twoMap.put("signType", "MD5");String paySign = "";try {paySign = qianming(secretKey, twoMap);//进行二次签名} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}//已准备好wx.requestPayment所需要的参数,返回参数给前端拉起支付！Map<String, String> overMap = new HashMap<>();overMap.put("timeStamp", timeStamp);overMap.put("nonceStr", nonceStr);overMap.put("package", package1);overMap.put("signType", "MD5");overMap.put("paySign", paySign);return overMap;}else {return null;}}/* 发送统一下单请求 */public String fasong(String xmlInfo, String URL) throws Exception {.URL postUrl = new URL(URL);// 打开连接HttpURLConnection connection = (HttpURLConnection) postUrl.openConnection();connection.setDoOutput(true);connection.setDoInput(true);connection.setRequestMethod("POST");connection.setUseCaches(false);connection.setInstanceFollowRedirects(true);connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");connection.connect();DataOutputStream out = new DataOutputStream(connection.getOutputStream());// String content = URLEncoder.encode("字符串值", "编码");out.writeBytes(xmlInfo);out.flush();out.close();// 获取响应BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));String line;String resultlin = "";while ((line = reader.readLine()) != null) {resultlin = resultlin + line;}reader.close();// 该干的都干完了,记得把连接断了connection.disconnect();return resultlin;}/* String转为Map */public Map<String, String> xmlStrToMap(String xmlStr) {System.out.println(xmlStr);Map<String, String> map = new HashMap<String, String>();Document doc;try {doc = DocumentHelper.parseText(xmlStr);Element root = doc.getRootElement();List children = root.elements();if (children != null && children.size() > 0) {for (int i = 0; i < children.size(); i++) {Element child = (Element) children.get(i);map.put(child.getName(), child.getTextTrim());}}} catch (Exception e) {e.printStackTrace();}return map;}/* 随机生成32位字符 */public String getram() {int maxNum = 58;int i;int count = 0;char[] str = { 'Z', 'Y', 'X', 'W', 'V', 'U', 'T', 'S', 'R', 'Q', 'P','O', 'N', 'M', 'L', 'K', 'J', 'I', 'H', 'G', 'F', 'E', 'D','C', 'B', 'A', 'z', 'y', 'x', 'w', 'v', 'u', 't', 's', 'r','q', 'p', 'o', 'n', 'm', 'l', 'k', 'j', 'i', 'h', 'g', 'f','e', 'd', 'c', 'b', 'a', '1', '2', '3', '4', '5', '6', '7','8', '9', '0' };StringBuffer pwd = new StringBuffer("");Random r = new Random();while (count < 32) {i = Math.abs(r.nextInt(maxNum));if (i >= 0 && i < str.length) {pwd.append(str[i]);count++;}}System.out.println(pwd.toString());return pwd.toString();}/* 签名加密 */public String qianming(String secretKey, Map<String, String> maps)throws UnsupportedEncodingException {// 1. 参数名按照ASCII码表升序排序String[] keys = maps.keySet().toArray(new String[0]);Arrays.sort(keys);// 2. 按照排序拼接参数名与参数值StringBuffer paramBuffer = new StringBuffer();for (String key : keys) {paramBuffer.append("&" + key).append(maps.get(key) == null ? "" : "=" + maps.get(key));}// 3. 将secretKey拼接到最后paramBuffer = paramBuffer.append("&key=" + secretKey);System.out.println(paramBuffer);String pa = paramBuffer.substring(1);// 4. MD5是128位长度的摘要算法，用16进制表示，一个十六进制的字符能表示4个位，所以签名后的字符串长度固定为32个十六进制字符。//return DigestUtils.md5Hex(pa.getBytes("UTF-8")).toUpperCase();return DigestUtils.md5DigestAsHex(pa.getBytes("UTF-8")).toUpperCase();}/* 获取IP地址 */public String getIp() throws Exception {InetAddress addr = InetAddress.getLocalHost();return addr.getHostAddress();}}
