之前写过一个APP支付宝支付，一直没有时间写APP微信支付。在写微信支付的时候，和前端调了好久，其实不是后端的事。我是觉得只要拿到了，预支付ID（prepay_id），前端就应该能调起来的。所以以后遇到说什么后端的事，简直就是坑爹啊。
下面就直接上代码了++++++++++++++++++++++++++++++++
下面的是APP支付的一些参数，最好先封装好，方便使用
public class WechatPayConstantWx { /** * APP微信支付 */ public static String API_KEY = "**************"; public static String APPID = "&&&&&&&&&&&&&&&"; public static String MCH_ID = "***********"; public static String trade_type = "APP"; public static String body = "……………………………………"; public static String wxnotify = "http://fg4dap.natappfree.cc/项目的名字/order-pay-wei-xin-notify-controller";// 微信回调地址 } // 生成签名 @SuppressWarnings("rawtypes") public static String createSign(String characterEncoding, SortedMap<String, Object> parameters) { StringBuffer sb = new StringBuffer(); Set es = parameters.entrySet();// 所有参与传参的参数按照accsii排序（升序） Iterator it = es.iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); String k = (String) entry.getKey(); Object v = entry.getValue(); if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) { sb.append(k + "=" + v + "&"); } } sb.append("key=" + WechatPayConstantWx.API_KEY);// 最后加密时添加商户密钥，由于key值放在最后，所以不用添加到SortMap里面去，单独处理，编码方式采用UTF-8 String sign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase(); return sign; }上面的是，生成签名的，这是第一次生成签名。后面还会有一次的————————————————————
请求XML封装
// 请求xml组装 @SuppressWarnings("rawtypes") public static String getRequestXml(SortedMap<String, Object> parameters) { StringBuffer sb = new StringBuffer(); sb.append("<xml>"); Set es = parameters.entrySet(); Iterator it = es.iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); String key = (String) entry.getKey(); String value; if (key.equals("total_fee")) { value = String.valueOf(entry.getValue()); } else { value = (String) entry.getValue(); } if ("attach".equalsIgnoreCase(key) || "body".equalsIgnoreCase(key) || "sign".equalsIgnoreCase(key)) { sb.append("<" + key + ">" + "<![CDATA[" + value + "]]></" + key + ">"); } else { sb.append("<" + key + ">" + value + "</" + key + ">"); } } sb.append("</xml>"); return sb.toString(); }请求方法
// 请求方法 public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) { try { URL url = new URL(requestUrl); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setDoOutput(true); conn.setDoInput(true); conn.setUseCaches(false); // 设置请求方式（GET/POST） conn.setRequestMethod(requestMethod); conn.setRequestProperty("content-type", "application/x-www-form-urlencoded"); // 当outputStr不为null时向输出流写数据 if (null != outputStr) { OutputStream outputStream = conn.getOutputStream(); // 注意编码格式 outputStream.write(outputStr.getBytes("UTF-8")); outputStream.close(); } // 从输入流读取返回内容 InputStream inputStream = conn.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8"); BufferedReader bufferedReader = new BufferedReader(inputStreamReader); String str = null; StringBuffer buffer = new StringBuffer(); while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } // 释放资源 bufferedReader.close(); inputStreamReader.close(); inputStream.close(); inputStream = null; conn.disconnect(); return buffer.toString(); } catch (ConnectException ce) { System.out.println("连接超时：{}" + ce); } catch (Exception e) { System.out.println("https请求异常：{}" + e); } return null; }XML解析
// xml解析 @SuppressWarnings({ "unchecked", "rawtypes" }) public static Map doXMLParse(String strxml) throws JDOMException, IOException { strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\""); if (null == strxml || "".equals(strxml)) { return null; } Map m = new HashMap(); InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8")); SAXBuilder builder = new SAXBuilder(); Document doc = builder.build(in); Element root = doc.getRootElement(); List list = root.getChildren(); Iterator it = list.iterator(); while (it.hasNext()) { Element e = (Element) it.next(); String k = e.getName(); String v = ""; List children = e.getChildren(); if (children.isEmpty()) { v = e.getTextNormalize(); } else { v = getChildrenText(children); } m.put(k, v); } // 关闭流 in.close(); return m; } 第一次就是，把订单信息根据微信给的文档加签，在就是XML封装好，在就是发送请求，请求之后，就解析XML，拿到预支付ID（prepay_id） 如果你没有拿到预支付ID，就看一下文档，是不是有什么错误的 是吧。》》》》》》》》》》》》》》》》》 private static Map<String, String> weixinPrePay(String trade_no, int actualPayMoney, String description, HttpServletRequest httpServletRequest) { SortedMap<String, Object> parameterMap = new TreeMap<String, Object>(); parameterMap.put("appid", WechatPayConstantWx.APPID); parameterMap.put("body", description); parameterMap.put("mch_id", WechatPayConstantWx.MCH_ID); parameterMap.put("nonce_str",PayCommonUtil.getRandomString(32)); parameterMap.put("notify_url", WechatPayConstantWx.wxnotify); parameterMap.put("out_trade_no", trade_no); parameterMap.put("fee_type", "CNY"); // 货币类型 parameterMap.put("spbill_create_ip", httpServletRequest.getRemoteAddr());// 终端IP System.out.println("===========================================" + httpServletRequest.getRemoteAddr()); parameterMap.put("total_fee", actualPayMoney); parameterMap.put("trade_type", WechatPayConstantWx.trade_type); String sign = PayCommonUtil.createSign("UTF-8", parameterMap); System.out.println("======================================================================" + sign); parameterMap.put("sign", sign); String requestXML = PayCommonUtil.getRequestXml(parameterMap); System.err.println(requestXML); String result = PayCommonUtil.httpsRequest("https://api.mch.weixin.qq.com/pay/unifiedorder", "POST", requestXML); System.err.println(result); Map<String, String> map = null; try { map = PayCommonUtil.doXMLParse(result); } catch (JDOMException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return map; }之后还需要在加签一次——————————————————————————————————
@Transactional @RequestMapping(value = "/wei-xin-order-pay-controller", method = { RequestMethod.POST }) public String OrderPay(@RequestBody String body, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception { log.info("微信支付接口 "); httpServletResponse.setContentType("text/html;charset=utf-8"); Request request = getRequest(body); Response response = getResponse(request); response.setUrl("wei-xin-order-pay-controller"); // 请求业务参数 OrderPayRequest orderPayRequest = JSONObject.parseObject(request.getBizContent(), OrderPayRequest.class); String trade_no = orderPayRequest.getOrderCode();// 商户订单号 String actualPayMoneys = orderPayRequest.getActualPayMoney(); Map<String, String> map =weixinPrePay(trade_no, actualPayMoneys, httpServletRequest); SortedMap<String, Object> finalpackage = new TreeMap<String, Object>(); finalpackage.put("appid", WechatPayConstantWx.APPID); finalpackage.put("noncestr", PayCommonUtil.getRandomString(32)); finalpackage.put("package", "Sign=WXPay"); finalpackage.put("partnerid", WechatPayConstantWx.MCH_ID);// 商户号 finalpackage.put("prepayid", map.get("prepay_id")); finalpackage.put("timestamp", String.valueOf(System.currentTimeMillis() / 1000)); System.err.println("=================================================" + map.get("prepay_id")); String sign = PayCommonUtil.createSign("UTF-8", finalpackage); finalpackage.put("sign", sign); response.setResult(finalpackage); System.err.println("============================================="+toFastJson(response)); httpServletResponse.getWriter().print(toFastJson(response)); return null; } toFastJson(response)++++++++++把这个直接给前端，他们去调微信支付=============下面的就是直接把response转化为JSON>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
public String toFastJson(Object obj) { String objStr = com.alibaba.fastjson.JSONObject.toJSONString(obj, SerializerFeature.WriteDateUseDateFormat, SerializerFeature.WriteMapNullValue); return objStr; }还有下面的两个方法，大家可以要，也可以不要>>>>>>>>>>>>>>>>>>>>
我也是为 做个笔记<<<<<<<<<<<<<<<<<<<<<<<<<<<<
/** * 微信MD5加签 * @author xyl * */ public class MD5Util { private static String byteArrayToHexString(byte b[]) { StringBuffer resultSb = new StringBuffer(); for (int i = 0; i < b.length; i++) resultSb.append(byteToHexString(b[i])); return resultSb.toString(); } private static String byteToHexString(byte b) { int n = b; if (n < 0) n += 256; int d1 = n / 16; int d2 = n % 16; return hexDigits[d1] + hexDigits[d2]; } public static String MD5Encode(String origin, String charsetname) { String resultString = null; try { resultString = new String(origin); MessageDigest md = MessageDigest.getInstance("MD5"); if (charsetname == null || "".equals(charsetname)) resultString = byteArrayToHexString(md.digest(resultString .getBytes())); else resultString = byteArrayToHexString(md.digest(resultString .getBytes(charsetname))); } catch (Exception exception) { } return resultString; } private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" }; } public class PayCommonUtil { // 微信参数配置 //public static String API_KEY = "b5c5345c033c5445e13ade6e10c2c796"; // 随机字符串生成 wxbe50da3d99876bc4 public static String getRandomString(int length) { // length表示生成字符串的长度 String base = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; Random random = new Random(); StringBuffer sb = new StringBuffer(); for (int i = 0; i < length; i++) { int number = random.nextInt(base.length()); sb.append(base.charAt(number)); } return sb.toString(); } // 请求xml组装 @SuppressWarnings("rawtypes") public static String getRequestXml(SortedMap<String, Object> parameters) { StringBuffer sb = new StringBuffer(); sb.append("<xml>"); Set es = parameters.entrySet(); Iterator it = es.iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); String key = (String) entry.getKey(); String value; if (key.equals("total_fee")) { value = String.valueOf(entry.getValue()); } else { value = (String) entry.getValue(); } if ("attach".equalsIgnoreCase(key) || "body".equalsIgnoreCase(key) || "sign".equalsIgnoreCase(key)) { sb.append("<" + key + ">" + "<![CDATA[" + value + "]]></" + key + ">"); } else { sb.append("<" + key + ">" + value + "</" + key + ">"); } } sb.append("</xml>"); return sb.toString(); } // 生成签名 @SuppressWarnings("rawtypes") public static String createSign(String characterEncoding, SortedMap<String, Object> parameters) { StringBuffer sb = new StringBuffer(); Set es = parameters.entrySet();// 所有参与传参的参数按照accsii排序（升序） Iterator it = es.iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); String k = (String) entry.getKey(); Object v = entry.getValue(); if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) { sb.append(k + "=" + v + "&"); } } sb.append("key=" + WechatPayConstantWx.API_KEY);// 最后加密时添加商户密钥，由于key值放在最后，所以不用添加到SortMap里面去，单独处理，编码方式采用UTF-8 String sign = MD5Util.MD5Encode(sb.toString(), characterEncoding).toUpperCase(); return sign; } /** * 验证回调签名 * * @param packageParams * @param key * @param charset * @return */ @SuppressWarnings("rawtypes") public static boolean isTenpaySign(Map<String, String> map) { String charset = "utf-8"; String signFromAPIResponse = map.get("sign"); if (signFromAPIResponse == null || signFromAPIResponse.equals("")) { System.out.println("API返回的数据签名数据不存在，有可能被第三方篡改!!!"); return false; } System.out.println("服务器回包里面的签名是:" + signFromAPIResponse); // 过滤空 设置 TreeMap SortedMap<String, String> packageParams = new TreeMap<>(); for (String parameter : map.keySet()) { String parameterValue = map.get(parameter); String v = ""; if (null != parameterValue) { v = parameterValue.trim(); } packageParams.put(parameter, v); } StringBuffer sb = new StringBuffer(); Set es = packageParams.entrySet(); Iterator it = es.iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); String k = (String) entry.getKey(); String v = (String) entry.getValue(); if (!"sign".equals(k) && null != v && !"".equals(v)) { sb.append(k + "=" + v + "&"); } } sb.append("key=" + WechatPayConstantWx.API_KEY); // 将API返回的数据根据用签名算法进行计算新的签名，用来跟API返回的签名进行比较 // 算出签名 String resultSign = ""; String tobesign = sb.toString(); if (null == charset || "".equals(charset)) { resultSign = MD5Util.MD5Encode(tobesign, "UTF8").toUpperCase(); } else { resultSign = MD5Util.MD5Encode(tobesign, "UTF8").toUpperCase(); } String tenpaySign = ((String) packageParams.get("sign")).toUpperCase(); return tenpaySign.equals(resultSign); } // 请求方法 public static String httpsRequest(String requestUrl, String requestMethod, String outputStr) { try { URL url = new URL(requestUrl); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setDoOutput(true); conn.setDoInput(true); conn.setUseCaches(false); // 设置请求方式（GET/POST） conn.setRequestMethod(requestMethod); conn.setRequestProperty("content-type", "application/x-www-form-urlencoded"); // 当outputStr不为null时向输出流写数据 if (null != outputStr) { OutputStream outputStream = conn.getOutputStream(); // 注意编码格式 outputStream.write(outputStr.getBytes("UTF-8")); outputStream.close(); } // 从输入流读取返回内容 InputStream inputStream = conn.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8"); BufferedReader bufferedReader = new BufferedReader(inputStreamReader); String str = null; StringBuffer buffer = new StringBuffer(); while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } // 释放资源 bufferedReader.close(); inputStreamReader.close(); inputStream.close(); inputStream = null; conn.disconnect(); return buffer.toString(); } catch (ConnectException ce) { System.out.println("连接超时：{}" + ce); } catch (Exception e) { System.out.println("https请求异常：{}" + e); } return null; } // xml解析 @SuppressWarnings({ "unchecked", "rawtypes" }) public static Map doXMLParse(String strxml) throws JDOMException, IOException { strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\""); if (null == strxml || "".equals(strxml)) { return null; } Map m = new HashMap(); InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8")); SAXBuilder builder = new SAXBuilder(); Document doc = builder.build(in); Element root = doc.getRootElement(); List list = root.getChildren(); Iterator it = list.iterator(); while (it.hasNext()) { Element e = (Element) it.next(); String k = e.getName(); String v = ""; List children = e.getChildren(); if (children.isEmpty()) { v = e.getTextNormalize(); } else { v = getChildrenText(children); } m.put(k, v); } // 关闭流 in.close(); return m; } @SuppressWarnings("rawtypes") public static String getChildrenText(List children) { StringBuffer sb = new StringBuffer(); if (!children.isEmpty()) { Iterator it = children.iterator(); while (it.hasNext()) { Element e = (Element) it.next(); String name = e.getName(); String value = e.getTextNormalize(); List list = e.getChildren(); sb.append("<" + name + ">"); if (!list.isEmpty()) { sb.append(getChildrenText(list)); } sb.append(value); sb.append("</" + name + ">"); } } return sb.toString(); } }