上一篇已經獲取到了用戶的OpenId
這篇主要是調用微信公眾支付的統一下單API
API地址:https://pay.weixin.qq.com/wiki/doc/api/jsapi. php?chapter=9_1
看文檔,主要流程就是把20個左右的參數封裝為XML格式發送到微信給的接口地址,然後就可以獲取到返回的內容了,如果成功裡面就有支付所需要的預付ID
請求參數就不解釋了。
其中,隨機字串:我用的是UUID去中劃線
public static String create_nonce_str() { return UUID.randomUUID().toString().replace("-",""); }
商家訂單號碼:每個訂單號碼只能使用一次,所以用的是系統的訂單號碼加的時間戳。
總金額:不能為
通知地址:微信支付成功或失敗回調給系統的地址
簽名:
import java.io.Serializable; public class PayInfo implements Serializable{ private static final long serialVersionUID = L; private String appid; private String mch_id; private String device_info; private String nonce_str; private String sign; private String body; private String attach; private String out_trade_no; private int total_fee; private String spbill_create_ip; private String notify_url; private String trade_type; private String openid; //下面是get,set方法 } /** * 创建统一下单的xml的java对象 * @param bizOrder 系统中的业务单号 * @param ip 用户的ip地址 * @param openId 用户的openId * @return */ public PayInfo createPayInfo(BizOrder bizOrder,String ip,String openId) { PayInfo payInfo = new PayInfo(); payInfo.setAppid(Constants.appid); payInfo.setDevice_info("WEB"); payInfo.setMch_id(Constants.mch_id); payInfo.setNonce_str(CommonUtil.create_nonce_str().replace("-", "")); payInfo.setBody("这里是某某白米饭的body"); payInfo.setAttach(bizOrder.getId()); payInfo.setOut_trade_no(bizOrder.getOrderCode().concat("A").concat(DateFormatUtils.format(new Date(), "MMddHHmmss"))); payInfo.setTotal_fee((int)bizOrder.getFeeAmount()); payInfo.setSpbill_create_ip(ip); payInfo.setNotify_url(Constants.notify_url); payInfo.setTrade_type("JSAPI"); payInfo.setOpenid(openId); return payInfo; }
獲取簽名:
/** * 获取签名 * @param payInfo * @return * @throws Exception */ public String getSign(PayInfo payInfo) throws Exception { String signTemp = "appid="+payInfo.getAppid() +"&attach="+payInfo.getAttach() +"&body="+payInfo.getBody() +"&device_info="+payInfo.getDevice_info() +"&mch_id="+payInfo.getMch_id() +"&nonce_str="+payInfo.getNonce_str() +"¬ify_url="+payInfo.getNotify_url() +"&openid="+payInfo.getOpenid() +"&out_trade_no="+payInfo.getOut_trade_no() +"&spbill_create_ip="+payInfo.getSpbill_create_ip() +"&total_fee="+payInfo.getTotal_fee() +"&trade_type="+payInfo.getTrade_type() +"&key="+Constants.key; //这个key注意 MessageDigest md = MessageDigest.getInstance("MD"); md.reset(); md.update(signTemp.getBytes("UTF-")); String sign = CommonUtil.byteToStr(md.digest()).toUpperCase(); return sign; }
注意:上面的Constants.key取值在商家號碼API安全的API金鑰中。
一些工具方法:取得ip位址,將位元組數組轉換為十六進位字串,將位元組轉換為十六進位字串
/** * 将字节数组转换为十六进制字符串 * * @param byteArray * @return */ public static String byteToStr(byte[] byteArray) { String strDigest = ""; for (int i = ; i < byteArray.length; i++) { strDigest += byteToHexStr(byteArray[i]); } return strDigest; } /** * 将字节转换为十六进制字符串 * * @param btyes * @return */ public static String byteToHexStr(byte bytes) { char[] Digit = { '', '', '', '', '', '', '', '', '', '', 'A', 'B', 'C', 'D', 'E', 'F' }; char[] tempArr = new char[]; tempArr[] = Digit[(bytes >>> ) & XF]; tempArr[] = Digit[bytes & XF]; String s = new String(tempArr); return s; } /** * 获取ip地址 * @param request * @return */ public static String getIpAddr(HttpServletRequest request) { InetAddress addr = null; try { addr = InetAddress.getLocalHost(); } catch (UnknownHostException e) { return request.getRemoteAddr(); } byte[] ipAddr = addr.getAddress(); String ipAddrStr = ""; for (int i = ; i < ipAddr.length; i++) { if (i > ) { ipAddrStr += "."; } ipAddrStr += ipAddr[i] & xFF; } return ipAddrStr; }
這樣就獲取了簽名,把簽名與PayInfo中的其他資料轉成XML格式,當做參數傳遞給統一下單位址。
PayInfo pi = pu.createPayInfo(bo,"...",""); String sign = pu.getSign(pi); pi.setSign(sign);
對象轉XML
/** * 扩展xstream使其支持CDATA */ private static XStream xstream = new XStream(new XppDriver() { public HierarchicalStreamWriter createWriter(Writer out) { return new PrettyPrintWriter(out) { //增加CDATA标记 boolean cdata = true; @SuppressWarnings("rawtypes") public void startNode(String name, Class clazz) { super.startNode(name, clazz); } protected void writeText(QuickWriter writer, String text) { if (cdata) { writer.write("<![CDATA["); writer.write(text); writer.write("]]>"); } else { writer.write(text); } } }; } }); public static String payInfoToXML(PayInfo pi) { xstream.alias("xml", pi.getClass()); return xstream.toXML(pi); }
xml轉Map
@SuppressWarnings("unchecked") public static Map<String, String> parseXml(String xml) throws Exception { Map<String, String> map = new HashMap<String, String>(); Document document = DocumentHelper.parseText(xml); Element root = document.getRootElement(); List<Element> elementList = root.elements(); for (Element e : elementList) map.put(e.getName(), e.getText()); return map; }
httpsRequest()這個方法在第一篇中
上面取得到的Map如果成功的話,裡面就會有log.info(MessageUtil.payInfoToXML(pi).replace("__", "_")); Map<String, String> map = CommonUtil.httpsRequestToXML("https://api.mch.weixin.qq.com/pay/unifiedorder", "POST", MessageUtil.payInfoToXML(pi).replace("__", "_").replace("<![CDATA[", "").replace("]]>", "")); log.info(map); public static Map<String, String> httpsRequestToXML(String requestUrl, String requestMethod, String outputStr) { Map<String, String> result = new HashMap<>(); try { StringBuffer buffer = httpsRequest(requestUrl, requestMethod, outputStr); result = MessageUtil.parseXml(buffer.toString()); } catch (ConnectException ce) { log.error("连接超时:"+ce.getMessage()); } catch (Exception e) { log.error("https请求异常:"+ece.getMessage()); } return result; }
這個prepay_id就是預付的ID。後面支付需要它。
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