准备

1.支付宝接口文档地址
2.准备好相对应的证书（普通公钥模式也行，但是B2C打款需要证书，所以在这里我用的是证书模式），文件如下：

3.准备好 appId，应用私钥、支付宝公钥及网关地址

开始

1.加入maven依赖

<dependency><groupId>com.alipay.sdk</groupId><artifactId>alipay-sdk-java</artifactId><version>4.9.124.ALL</version>
</dependency>

2.定义一个创建支付宝客户端的公用方法

import com.alipay.api.AlipayClient;
import com.alipay.api.CertAlipayRequest;
import com.alipay.api.DefaultAlipayClient;
import org.apache.logging.log4j.util.PropertiesUtil;
import org.springframework.util.ResourceUtils;public class AliPayCreateClient {/*** 创建支付宝客户端** @throws Exception*/public static AlipayClient createAlipayClient(AlipayClient alipayClient) throws Exception {if (alipayClient == null) {//构造clientCertAlipayRequest certAlipayRequest = new CertAlipayRequest();//设置网关地址certAlipayRequest.setServerUrl("网关地址");//设置应用AppIdcertAlipayRequest.setAppId("AppId");//设置应用私钥certAlipayRequest.setPrivateKey("应用私钥");certAlipayRequest.setFormat("JSON");//设置字符集certAlipayRequest.setCharset("UTF-8");//设置签名类型certAlipayRequest.setSignType("RSA2");if(PropertiesUtil.getSystemProperties().getProperty("os.name").equals("Linux")){//设置应用公钥证书路径certAlipayRequest.setCertPath("./aliPay/appCertPublicKey_****.crt");//设置支付宝公钥证书路径certAlipayRequest.setAlipayPublicCertPath("./aliPay/alipayCertPublicKey_RSA2.crt");//设置支付宝根证书路径certAlipayRequest.setRootCertPath("./aliPay/alipayRootCert.crt");}else{//设置应用公钥证书路径certAlipayRequest.setCertPath(ResourceUtils.getURL("classpath:").getPath() + "/aliPay/appCertPublicKey_****.crt");//设置支付宝公钥证书路径certAlipayRequest.setAlipayPublicCertPath(ResourceUtils.getURL("classpath:").getPath() + "/aliPay/alipayCertPublicKey_RSA2.crt");//设置支付宝根证书路径certAlipayRequest.setRootCertPath(ResourceUtils.getURL("classpath:").getPath() + "/aliPay/alipayRootCert.crt");}alipayClient = new DefaultAlipayClient(certAlipayRequest);}return alipayClient;}
}

3.定义一个请求支付宝的公用方法

import com.alibaba.fastjson.JSONObject;
import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.domain.AccessParams;
import com.alipay.api.domain.Participant;
import com.alipay.api.domain.PeriodRuleParams;
import com.alipay.api.domain.SignParams;
import com.alipay.api.request.*;
import com.alipay.api.response.*;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;
import org.apache.http.entity.ContentType;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.web.multipart.MultipartFile;import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;public class AliPayTool {/*** 生成支付宝分享码* @param alipayClient* @param url  分享路径* @param shareCode  分享码* @return* @throws Exception* @return shareCodeUrl  二维码路径   shareCodeUrlText  二维码里面的字符串*/public static AjaxResult aliCreateQR(AlipayClient alipayClient,String url, String shareCode) throws Exception {AlipayOpenAppQrcodeCreateRequest request = new AlipayOpenAppQrcodeCreateRequest();Map<String, Object> params = new HashMap<String, Object>();params.put("url_param", url + "?shareCode=" + shareCode);params.put("query_param", "shareCode=" + shareCode);params.put("describe", "分享二维码");Object obj = JSONObject.toJSON(params);request.setBizContent(obj.toString());AlipayOpenAppQrcodeCreateResponse response = alipayClient.certificateExecute(request);Map<String, String> map = new HashMap<>();map.put("shareCodeUrl", response.getQrCodeUrl());HttpURLConnection httpUrl = (HttpURLConnection) new URL(response.getQrCodeUrl()).openConnection();httpUrl.connect();File pdfFile = FileUtils.inputStreamToFile(httpUrl.getInputStream(), "url.png");FileInputStream fileInputStream = new FileInputStream(pdfFile);MultipartFile multipartFile = new MockMultipartFile(pdfFile.getName(), pdfFile.getName(), ContentType.APPLICATION_OCTET_STREAM.toString(), fileInputStream);BufferedImage image = ImageIO.read(multipartFile.getInputStream());BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(image)));// 定义二维码的参数:HashMap<DecodeHintType, Object> hints = new HashMap<>();// 定义字符集hints.put(DecodeHintType.CHARACTER_SET, "utf-8");Result result = new MultiFormatReader().decode(binaryBitmap, hints);map.put("shareCodeUrlText", result.getText());if (response.isSuccess()) {return AjaxResult.success().data(map);} else {return AjaxResult.success().data("");}}/*** 支付宝小程序授权** @param code  前端传过来的授权code* @return* @throws AlipayApiException*/public static AlipaySystemOauthTokenResponse aliPayAuthorization(AlipayClient alipayClient,String code) throws Exception {AlipaySystemOauthTokenRequest requestToken = new AlipaySystemOauthTokenRequest();requestToken.setGrantType("authorization_code");requestToken.setCode(code);System.out.println(requestToken.getTextParams());//request.setRefreshToken("201208134b203fe6c11548bcabd8da5bb087a83b");AlipaySystemOauthTokenResponse responseToken = alipayClient.certificateExecute(requestToken);System.out.println(responseToken.getParams());if (responseToken.isSuccess()) {return responseToken;} else {return null;}}/*** 支付宝创建订单** @param orderSn  商户订单编号* @param subject  主体* @param totalAmount  总额* @param logUserId  支付宝userId* @param  notifyUrl 第四步创建的回调地址* @return* @throws Exception*/public static String aliPayTradeCreate(AlipayClient alipayClient,String orderSn, String subject, double totalAmount, String logUserId,String notifyUrl) throws Exception {//实例化具体API对应的request类,类名称和接口名称对应,当前调用接口名称：alipay.trade.create.AlipayTradeCreateRequest request = new AlipayTradeCreateRequest();request.setNotifyUrl(notifyUrl);Map<String, Object> params = new HashMap<String, Object>();params.put("out_trade_no", orderSn);params.put("total_amount", totalAmount);params.put("subject", subject);params.put("buyer_id", logUserId);Object obj = JSONObject.toJSON(params);System.err.println("创建订单成功");System.out.println(params);//SDK已经封装掉了公共参数，这里只需要传入业务参数。request.setBizContent(obj.toString());AlipayTradeCreateResponse response = alipayClient.certificateExecute(request);if (response.isSuccess()) {return response.getTradeNo();// 获取返回的tradeNO。} else {return null;}}/*** 支付宝查找订单** @param outTradeNo  商户支付宝订单号* @return* @throws Exception*/public static AlipayTradeQueryResponse alipayTradeQuery(AlipayClient alipayClient,String outTradeNo) throws Exception {Map<String, Object> map = new HashMap<>();Map<String, Object> params = new HashMap<String, Object>();params.put("out_trade_no", outTradeNo);//支付宝订单号Object obj = JSONObject.toJSON(params);AlipayTradeQueryRequest request = new AlipayTradeQueryRequest();request.setBizContent(obj.toString());return alipayClient.certificateExecute(request);}/*** 支付宝退款** @param orderSn  商户订单号* @param moeny* @throws Exception*/public static AlipayTradeRefundResponse alipayTradeRefund(AlipayClient alipayClient,String orderSn, double moeny) throws Exception {AlipayTradeRefundRequest request = new AlipayTradeRefundRequest();Map<String, Object> params = new HashMap<String, Object>();params.put("out_trade_no", orderSn);params.put("refund_amount", moeny);params.put("refund_reason", "正常退款");Object obj = JSONObject.toJSON(params);request.setBizContent(obj.toString());AlipayTradeRefundResponse response = alipayClient.certificateExecute(request);return response;}/*** 支付宝b2c打钱** @param aliPayUserId* @param titel   标题* @param money   金额* @param orderSn  商户订单编号* @return* @throws Exception*/public static AlipayFundTransUniTransferResponse aliPayB2C(AlipayClient alipayClient,String aliPayUserId, String titel, double money, String orderSn) throws Exception {AlipayFundTransUniTransferRequest request = new AlipayFundTransUniTransferRequest();Participant participant = new Participant();participant.setIdentity(aliPayUserId);participant.setIdentityType("ALIPAY_USER_ID");Map<String, Object> params = new HashMap<String, Object>();params.put("out_biz_no", orderSn);params.put("trans_amount", money);params.put("product_code", "TRANS_ACCOUNT_NO_PWD");params.put("biz_scene", "DIRECT_TRANSFER");params.put("order_title", titel);params.put("payee_info", participant);Object obj = JSONObject.toJSON(params);request.setBizContent(obj.toString());AlipayFundTransUniTransferResponse response = alipayClient.certificateExecute(request);return response;}
}

4.在controller里面定义一个接口，用于接收支付宝的回调

    /*** 支付宝异步通知** @param response* @param request* @throws Exception*/@PostMapping(value = "/notifyUrl")@ResponseBodypublic void notifyUrl(HttpServletResponse response, HttpServletRequest request) throws Exception {PrintWriter out = response.getWriter();Long startDate = System.currentTimeMillis();System.out.println("异步通知");request.setCharacterEncoding("utf-8");//乱码解决，这段代码在出现乱码时使用System.out.println();for (String personkey : request.getParameterMap().keySet()) {System.out.println(personkey + ", 来自: " + request.getParameterMap().get(personkey));}//获取支付宝POST过来反馈信息Map<String, String> params = new HashMap<String, String>();Map<String, String[]> requestParams = request.getParameterMap();for (String str : requestParams.keySet()) {String name = str;String[] values = (String[]) requestParams.get(name);String valueStr = "";for (int i = 0; i < values.length; i++) {valueStr = (i == values.length - 1) ? valueStr + values[i]: valueStr + values[i] + ",";}params.put(name, valueStr);}boolean signVerified = AlipaySignature.rsaCheckV1(params, "你的支付宝公钥", "UTF-8", "RSA2"); //调用SDK验证签名if (!signVerified) {System.out.println("验签失败");out.print("fail");return;}String notifyType = params.get("notify_type");//付款异步通知if ("trade_status_sync".equals(notifyType)) {String outTradeNo = params.get("out_trade_no");String trade_status = new String(request.getParameter("trade_status").getBytes("ISO-8859-1"), "UTF-8");if (trade_status.equals("TRADE_SUCCESS")) {//主动查询AlipayTradeQueryResponse alipayTradeQueryResponse = aliPayAppService.alipayTradeQueryApp(outTradeNo);if (alipayTradeQueryResponse.isSuccess()) {alipayTradeQueryResponse.getTradeStatus();if (!"TRADE_SUCCESS".equals(alipayTradeQueryResponse.getTradeStatus())) {return;}}/*****你的业务逻辑***/System.out.println(outTradeNo + "支付回调总花费：" + (System.currentTimeMillis() - startDate) + "毫秒;" + DateUtils.parseDateToStr("yyyy-MM-dd", new Date()));}}}