微信支付的前期准备：
- 小程序的appId和密钥(小程序配置界面)
- 商户号和api密钥(商家后台自己设置)
整理支付的逻辑：
附：官方微信统一下单传送门API
- 在微信小程序端调用支付前，先组装支付的金额给后台发送请求，后台需要调用微信API统一下单
- 微信统一下单成功后，微信返回支付的5个参数
- 拿到5个参数，方可在小程序端调用wx.requestPayment()，在此微信弹出支付填写密码的界面
- 用户支付成功，微信发起支付成功通知，后台接受通知整理支付成功逻辑
微信退款逻辑：
附：微信官方退款传送门API
- 用户主动发起退款，拿到订单信息，退款理由（可选）
- 调用退款接口
- 退款成功后，微信发起退款成功回调，整理退款后的逻辑
流程图如下：
微信wxml代码：
<button bindtap='payment'>支付</button>微信js代码：
//在这里演示支付的过程,获取openid不做解释 payment:function(){ //请求后台发起支付，获取5个参数，data中放入支付的总额及其openid //请求为示例 wx.request({ url: 'http:127.0.0.1:8080/project/payment', data: { openid: openid, amount: amount}, method:'POST', header: { 'Content-Type': 'application/x-www-form-urlencoded'}, success:res => { if(res){ //接受的5个参数，调用这个方法成功，微信就会弹出输入密码的界面 wx.requestPayment({ timeStamp: res.timeStamp, nonceStr: res.nonceStr, package: res.package, signType: res.signType, paySign: res.paySign, success:payRes => { //支付成功后，可以做一些逻辑判断 console.log('支付成功！'); console.dir(payRes); }, fail:payFail => { console.log('支付失败！'); console.dir(payFail); } }) }else{ console.log('后台没有接受到5个参数'); } }, fail:fail => { console.log('支付获取参数失败！'); console.dir(fail); } }) }java后台代码：
后台的支付主要使用了两个包：
- com.jpay.ext.kit.PaymentKit 【附参考微信官方的sdk和demo】
- com.jpay.weixin.api.WxPayApi【附包中源码】
package com.test.service;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.math.BigDecimal;import java.net.URLEncoder;import java.util.HashMap;import java.util.Map;import java.util.Random;import java.util.SortedMap;import java.util.TreeMap;import java.util.UUID;import java.security.KeyStore;import java.security.SecureRandom;import javax.net.ssl.SSLContext;import javax.servlet.Servlet;import javax.servlet.http.HttpServletRequest;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.utils.URLEncodedUtils;import org.apache.commons.lang3.StringUtils;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.config.RequestConfig;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.SSLContexts;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Service;import org.springframework.transaction.annotation.Isolation;import org.springframework.transaction.annotation.Transactional;import com.google.common.collect.Maps;import com.jpay.ext.kit.PaymentKit;import io.swagger.util.Json;import net.sf.json.JSONObject;@Service@Transactional(isolation = Isolation.READ_COMMITTED, rollbackFor = Exception.class)public class testService {private static final Logger logger = LoggerFactory.getLogger(test.class);private static final String appid = "wx6edb*******9c18";private static final String secret = "*****cff44ae9fe25*********e7c";private static final String grant_type = "authorization_code";private static final String mch_id = "83595*****";//商户号 private static final String partnerKey = "EpTC3d7i9YGKBg9a********";//商户平台设置的密钥keyprivate static final String transaction_type = "JSAPI";//微信小程序支付交易类型private static final String refund_path = "https://api.mch.weixin.qq.com/secapi/pay/refund";//微信退款地址/** * 微信付款或者退款车成功后，需要配置外网可以访问后台接口进行一些逻辑操作 */private static final String pay_notify_url = "";//支付成功以后回调接口地址private static final String refund_notify_url = "";//退款成功以后回调接口地址private int socketTimeout = 10 * 1000;// 连接超时时间，默认10s private int connectTimeout = 30 * 1000;// 传输超时时间，默认30s private static RequestConfig requestConfig;// 请求器的配置 private static CloseableHttpClient httpClient;// HTTP请求器/** * 微信支付统一下单 * @param map * @param request * @return */public JSONObject payment(Map<String, Object> map, HttpServletRequest request) {//用户已经登录openid在小程序端发送过来 String openId = String.valueOf(map.get("openid")); //参数中获取订单总额 BigDecimal amount = new BigDecimal(String.valueOf(map.get("amount"))); BigDecimal beishu = new BigDecimal("100"); amount = amount.multiply(beishu); try{ String body = "XXX程序-支付"; SortedMap<String, String> paramMap = new TreeMap<String, String>(); //小程序的appid paramMap.put("appid", appid); //商户id paramMap.put("mch_id", mch_id); //随机字符串 paramMap.put("nonce_str", getRandomString()); //商品描述 paramMap.put("body", body); //商户订单号码,自己生成调用即可 paramMap.put("out_trade_no", "1234567890"); //标价金额 paramMap.put("total_fee", String.valueOf(amount)); //终端IP paramMap.put("spbill_create_ip", request.getRemoteAddr()); //通知地址 paramMap.put("notify_url", pay_notify_url); //交易类型 paramMap.put("trade_type", transaction_type); //openid(在接口文档中 如果交易类型设置成'JSAPI'则必须传入openid) paramMap.put("openid", openId); //随机签名 paramMap.put("sign", PaymentKit.createSign(paramMap, partnerKey)); //统一下单 String xmlResult = WxPayApi.pushOrder(false, paramMap); //解析统一下单返回结果的xml Map<String, String> xmlMap = PaymentKit.xmlToMap(xmlResult); String returnCode = String.valueOf(xmlMap.get("return_code")); String resultMsg = String.valueOf(map.get("return_msg")); //组装返回小程序的支付参数 Map<String, String> resultMap = new HashMap<String, String>(); if ("SUCCESS".equals(returnCode)){ resultMap.put("appId", appid); resultMap.put("nonceStr", getRandomString()); resultMap.put("package", "prepay_id=" + String.valueOf(xmlMap.get("prepay_id"))); resultMap.put("signType", "MD5"); resultMap.put("timeStamp", String.valueOf(getCurrentTimestampMs())); String paySign = PaymentKit.createSign(resultMap, partnerKey).toUpperCase(); resultMap.put("paySign", paySign); return JSONObject.fromObject(resultMap); }else{ logger.info("支付返回状态码错误 ===>" + returnCode); logger.info("支付返回状态码错误 ===>" + getMsg(returnCode)); return JSONObject.fromObject(getMsg(returnCode)); } }catch (Exception e){ System.out.println(e); logger.error(java.lang.Thread.currentThread().getStackTrace()[1].getMethodName() + "支付异常是: ", e); } } /** * 申请退款 * * @param out_trade_no 订单编号 * @param total_fee 订单金额 * @param refund_fee 退款金额 * @param refund_desc 退款原因 * @throws Exception */ public Map<String, Object> refund(String out_trade_no, Double total_fee, Double refund_fee,String refund_desc) throws Exception { Map<String, Object> resultMap = new HashMap<String, Object>(); Map<String, String> paramMap = new HashMap<String, String>(); try { paramMap.put("appid", appid); paramMap.put("mch_id", mch_id); paramMap.put("nonce_str", getRandomString()); paramMap.put("sign_type", "MD5"); // 商户订单号，官方API这个参数和微信订单号二选一 paramMap.put("out_trade_no", out_trade_no); //商户退款单号 paramMap.put("out_refund_no", getRandomString()); // 支付金额，微信支付提交的金额是不能带小数点的，且是以分为单位,这边需要转成字符串类型，否则后面的签名会失败 paramMap.put("total_fee", String.valueOf(Math.round(refund_fee * 100))); // 退款总金额,订单总金额,单位为分,只能为整数 paramMap.put("refund_fee", String.valueOf(Math.round(refund_fee * 100))); paramMap.put("notify_url", refund_notify_url);// 退款成功后的回调地址 // 退款原因，退款金额大于1块，且是完全退款才会显示 paramMap.put("refund_desc", refund_desc);//退款原因 // 把数组所有元素，按照“参数=参数值”的模式用“&”字符拼接成字符串 String preStr = WXPayUtil.createLinkString(paramMap); // MD5运算生成签名，这里是第一次签名，用于调用统一下单接口 String sign = WXPayUtil.sign(preStr, partnerKey, "utf-8").toUpperCase(); paramMap.put("sign", sign); // 拼接统一下单接口使用的xml数据，要将上一步生成的签名一起拼接进去 logger.info("微信请求xml=====>",PaymentKit.toXml(paramMap)); //微信支付是以xml通知 String xmlStr = sendPostReques(refund_path, PaymentKit.toXml(paramMap)); logger.info("微信退款的拼接xml=====>",xmlStr); // 把xml转成map Map<String, String> notifyMap = PaymentKit.xmlToMap(xmlStr); // 退款成功 if ("SUCCESS".equals(notifyMap.get("result_code"))) { // 返回的预付单信息 String prepay_id = notifyMap.get("prepay_id"); logger.info("微信退款返回的预付单信息=====>",prepay_id); // 拼接签名参数 String stringSignTemp = "appId=" + appid + "&nonceStr=" + getRandomString() + "&package=prepay_id=" + prepay_id + "&signType=MD5&timeStamp=" + String.valueOf(getCurrentTimestamp()); resultMap.put("package", "prepay_id=" + prepay_id); resultMap.put("timeStamp", String.valueOf(getCurrentTimestamp())); resultMap.put("paySign", WXPayUtil.sign(stringSignTemp, partnerKey, "utf-8").toUpperCase()); resultMap.put("result", "success"); } else { resultMap.put("result", "fail"); resultMap.put("msg", notifyMap.get("return_msg")); logger.info("退款失败：",notifyMap.get("return_msg")); } } catch (Exception e) { resultMap.put("result", "fail"); resultMap.put("msg", e.getMessage()); logger.error(e.toString(), e); } return resultMap; } /** * 通过Https往API post xml数据 * * @param url API地址 * @param xmlObj 要提交的XML数据对象 * @return */ public String sendPostReques(String url, String xmlObj) { // 加载证书 try { loadingCert(); } catch (Exception e) { e.printStackTrace(); } String result = null; HttpPost httpPost = new HttpPost(url); // 得指明使用UTF-8编码，否则到API服务器XML的中文不能被成功识别 StringEntity postEntity = new StringEntity(xmlObj, "UTF-8"); httpPost.addHeader("Content-Type", "text/xml"); httpPost.setEntity(postEntity); // 根据默认超时限制初始化requestConfig requestConfig = RequestConfig.custom().setSocketTimeout(socketTimeout) .setConnectTimeout(connectTimeout).build(); // 设置请求器的配置 httpPost.setConfig(requestConfig); try { HttpResponse response = null; try { response = httpClient.execute(httpPost); } catch (IOException e) { e.printStackTrace(); } HttpEntity entity = response.getEntity(); try { result = EntityUtils.toString(entity, "UTF-8"); } catch (IOException e) { e.printStackTrace(); } } finally { httpPost.abort(); } return result; } /** * 加载证书，先取到证书在项目的位置，然后读取证书中的内容 * @throws Exception */ private void loadingCert() throws Exception { // 证书密码，默认为商户ID String key = mch_id; String realPath = testService.class.getClassLoader().getResource("").getPath(); try { realPath = URLEncoder.encode(realPath,"UTF-8");} catch (Exception e) {logger.info("转换url出错：" + e);realPath = realPath.replace("%20", " ");} // 拿到证书的根目录(根据证书所在项目的位置来拿) // realPath = realPath.replace("/classes", ""); // 商户证书PKCS12的路径 String path = realPath + "cert/apiclient_cert.p12"; // 指定读取证书格式为PKCS12 KeyStore keyStore = KeyStore.getInstance("PKCS12"); // 读取本机存放的PKCS12证书文件 FileInputStream instream = new FileInputStream(new File(path)); try { // 指定PKCS12的密码(商户ID) keyStore.load(instream, key.toCharArray()); } finally { instream.close(); } SSLContext sslcontext = SSLContexts.custom().loadKeyMaterial(keyStore, key.toCharArray()).build(); // 指定TLS版本 SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslcontext, new String[] {"TLSv1"}, null, SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER); // 设置httpclient的SSLSocketFactory httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build(); } /** * 提示信息 * * @param code * @return */private String getMsg(String code) { switch (code) { case "NOTENOUGH": return "您的账户余额不足！"; case "ORDERPAID": return "该订单已支付完成,请勿重复支付！"; case "ORDERCLOSED": return "当前订单已关闭，请重新下单！"; case "SYSTEMERROR": return "系统超时，请重新支付！"; case "OUT_TRADE_NO_USED": return "请勿重复提交该订单！"; default: return "网络正在开小差,请稍后再试！"; } } /** * 随机字符串 * @return */private static String getRandomString(){final String SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";final Random RANDOM = new SecureRandom();char[] nonceChars = new char[32]; for (int index = 0; index < nonceChars.length; ++index) { nonceChars[index] = SYMBOLS.charAt(RANDOM.nextInt(SYMBOLS.length())); } return new String(nonceChars);} /** * 获取当前时间戳，单位秒 * @return */ public static long getCurrentTimestamp() { return System.currentTimeMillis()/1000; } /** * 获取当前时间戳，单位毫秒 * @return */ public static long getCurrentTimestampMs() { return System.currentTimeMillis(); }}支付和退款使用的工具类：
package com.test.utils;import java.io.BufferedReader;import java.io.ByteArrayInputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.UnsupportedEncodingException;import java.net.HttpURLConnection;import java.net.URL;import java.security.SignatureException;import java.util.ArrayList;import java.util.Collections;import java.util.List;import java.util.Map;import org.apache.commons.codec.digest.DigestUtils;public class WXPayUtil {/** * 签名字符串 * * @param text 需要签名的字符串 * @param key 密钥 * @param input_charset 编码格式 * @return 签名结果 */ public static String sign(String text, String key, String input_charset) { text = text + "&key=" + key; return DigestUtils.md5Hex(getContentBytes(text, input_charset)); } /** * @param content * @param charset * @return * @throws SignatureException * @throws UnsupportedEncodingException */ public static byte[] getContentBytes(String content, String charset) { if (charset == null || "".equals(charset)) { return content.getBytes(); } try { return content.getBytes(charset); } catch (UnsupportedEncodingException e) { throw new RuntimeException("MD5签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:" + charset); } } /** * 把数组所有元素排序，并按照“参数=参数值”的模式用“&”字符拼接成字符串 * * @param params 需要排序并参与字符拼接的参数组 * @return 拼接后字符串 */ public static String createLinkString(Map<String, String> params) { List<String> keys = new ArrayList<String>(params.keySet()); Collections.sort(keys); String preStr = ""; for (int i = 0; i < keys.size(); i++) { String key = keys.get(i); String value = params.get(key); if (i == keys.size() - 1) {// 拼接时，不包括最后一个&字符 preStr = preStr + key + "=" + value; } else { preStr = preStr + key + "=" + value + "&"; } } return preStr; } /** * * @param requestUrl 请求地址 * @param requestMethod 请求方法 * @param outputStr 参数 */ public static String httpRequest(String requestUrl, String requestMethod, String outputStr) { // 创建SSLContext StringBuffer buffer = null; try { URL url = new URL(requestUrl); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod(requestMethod); conn.setDoOutput(true); conn.setDoInput(true); conn.connect(); // 往服务器端写内容 if (null != outputStr) { OutputStream os = conn.getOutputStream(); os.write(outputStr.getBytes("utf-8")); os.close(); } // 读取服务器端返回的内容 InputStream is = conn.getInputStream(); InputStreamReader isr = new InputStreamReader(is, "utf-8"); BufferedReader br = new BufferedReader(isr); buffer = new StringBuffer(); String line = null; while ((line = br.readLine()) != null) { buffer.append(line); } } catch (Exception e) { e.printStackTrace(); } return buffer.toString(); } public static String urlEncodeUTF8(String source) { String result = source; try { result = java.net.URLEncoder.encode(source, "UTF-8"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } return result; } /** * 解析xml,返回第一级元素键值对。如果第一级元素有子节点，则此节点的值是子节点的xml数据。 * * @param strxml * @return * @throws IOException */ public static InputStream String2Inputstream(String strxml) throws IOException { return new ByteArrayInputStream(strxml.getBytes("UTF-8")); } public static String GetMapToXML(Map<String, String> param) { StringBuffer sb = new StringBuffer(); sb.append("<xml>"); for (Map.Entry<String, String> entry : param.entrySet()) { sb.append("<" + entry.getKey() + ">"); sb.append(entry.getValue()); sb.append("</" + entry.getKey() + ">"); } sb.append("</xml>"); return sb.toString(); } }
