1 ：引入  支付 jar包

  <dependency><groupId>com.alipay.sdk</groupId><artifactId>alipay-sdk-java</artifactId><version>3.7.4.ALL</version></dependency>

 2 引入 配置 修改  参数

app_id  merchant_private_key   alipay_public_key  

app_id  秘钥 可以参考 上篇文章   （https://blog.csdn.net/qq_34789780/article/details/103985710）

package com.vue.vueapp.config;import java.io.FileWriter;
import java.io.IOException;public class AlipayConfig {public static String app_id = "******";// 商户私钥，您的PKCS8格式RSA2私钥public static String merchant_private_key = "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";// 支付宝公钥,查看地址：https://openhome.alipay.com/platform/keyManage.htm 对应APPID下的支付宝公钥。public static String alipay_public_key = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAk6q00fXHYHOyV34dP9tn5HQvS3BIWIznmVgRQptJIJIFZKi92bvKrSlOjLamt6wO5nlJDDcObPusR/i1k9nmbdhAjLX1N/oID2uFL/hUYNADh+b6qKHlg/UIcE24kf/svCBfuV7AdOrZ/d2IN5rivs6YFYDEofX3jvwevi4u97pv1RwCNdv5McpdAOtKwiKnxs0YptoLdMFoKWDIDmqrXNBnxfX0aJNJw/VAvk5Pj9qZ49vozralNkfagSn3Xc0Co7nrwfoxDhoD8C36ZW6d9ebl03rEgqtzABDO8aWNzfud4ue/6vDW1GfrSC67mvrQwG5A/zUzaSxWofz5TpIAJQIDAQAB";// 服务器异步通知页面路径  需http://格式的完整路径，不能加?id=123这类自定义参数，必须外网可以正常访问public static String notify_url = "http://182.92.97.65:8081/notify_url.view";// 页面跳转同步通知页面路径 需http://格式的完整路径，不能加?id=123这类自定义参数，必须外网可以正常访问public static String return_url = "http://182.92.97.65:8081/return_url.view";// 签名方式public static String sign_type = "RSA2";// 字符编码格式public static String charset = "utf-8";// 支付宝网关public static String gatewayUrl = "https://openapi.alipaydev.com/gateway.do";// 支付宝网关public static String log_path = "C:\\";//↑↑↑↑↑↑↑↑↑↑请在这里配置您的基本信息↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑/** * 写日志，方便测试（看网站需求，也可以改成把记录存入数据库）* @param sWord 要写入日志里的文本内容*/public static void logResult(String sWord) {FileWriter writer = null;try {writer = new FileWriter(log_path + "alipay_log_" + System.currentTimeMillis()+".txt");writer.write(sWord);} catch (Exception e) {e.printStackTrace();} finally {if (writer != null) {try {writer.close();} catch (IOException e) {e.printStackTrace();}}}}
}

3 编写 控制器  PayController 

package com.vue.vueapp.controller;import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.alipay.api.internal.util.AlipaySignature;
import com.alipay.api.request.AlipayTradePagePayRequest;
import com.vue.vueapp.config.AlipayConfig;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.UUID;@Controller
public class PayController {@RequestMapping(value = "pay")public void pay(HttpServletRequest req, ModelAndView  modelAndView, HttpServletResponse rep) throws AlipayApiException, IOException {//获得初始化的AlipayClientAlipayClient alipayClient = new DefaultAlipayClient(AlipayConfig.gatewayUrl, AlipayConfig.app_id, AlipayConfig.merchant_private_key, "json", AlipayConfig.charset, AlipayConfig.alipay_public_key, AlipayConfig.sign_type);//设置请求参数AlipayTradePagePayRequest alipayRequest = new AlipayTradePagePayRequest();alipayRequest.setReturnUrl(AlipayConfig.return_url);alipayRequest.setNotifyUrl(AlipayConfig.notify_url);//商户订单号，商户网站订单系统中唯一订单号，必填String out_trade_no = UUID.randomUUID().toString().replace("-","");//付款金额，必填  (随机生成 0-1000)String total_amount =String.valueOf(Math.floor(Math.random() * 1000+1));//订单名称，必填String subject = "订单名称";//商品描述，可空String body = "特价苹果";alipayRequest.setBizContent("{\"out_trade_no\":\""+ out_trade_no +"\","+ "\"total_amount\":\""+ total_amount +"\","+ "\"subject\":\""+ subject +"\","+ "\"body\":\""+ body +"\","+ "\"product_code\":\"FAST_INSTANT_TRADE_PAY\"}");//请求String result = alipayClient.pageExecute(alipayRequest).getBody();rep.setContentType("text/html;charset=" + AlipayConfig.charset);rep.getWriter().write(result);//直接将完整的表单html输出到页面rep.getWriter().flush();rep.getWriter().close();}/*** 回调路径return_url* @param request* @param response* @throws AlipayApiException* @throws*/@RequestMapping("return_url.view")@ResponseBodypublic String returnUrl(HttpServletRequest request, HttpServletResponse response) throws AlipayApiException, UnsupportedEncodingException, UnsupportedEncodingException {System.out.println("调用 同步 回调");//获取支付宝POST过来反馈信息Map<String,String> params = new HashMap<String,String>();Map requestParams = request.getParameterMap();for (Iterator iter = requestParams.keySet().iterator(); iter.hasNext();) {String name = (String) iter.next();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] + ",";}//乱码解决，这段代码在出现乱码时使用。//valueStr = new String(valueStr.getBytes("ISO-8859-1"), "utf-8");params.put(name, valueStr);}//切记alipaypublickey是支付宝的公钥，请去open.alipay.com对应应用下查看。//boolean AlipaySignature.rsaCheckV1(Map<String, String> params, String publicKey, String charset, String sign_type)boolean signVerified = AlipaySignature.rsaCheckV1(params, AlipayConfig.alipay_public_key, AlipayConfig.charset,AlipayConfig.sign_type);if(signVerified) {//商户订单号String out_trade_no = new String(request.getParameter("out_trade_no").getBytes("ISO-8859-1"),"UTF-8");//支付宝交易号String trade_no = new String(request.getParameter("trade_no").getBytes("ISO-8859-1"),"UTF-8");//付款金额String total_amount = new String(request.getParameter("total_amount").getBytes("ISO-8859-1"),"UTF-8");request.setAttribute("out_trade_no", out_trade_no);request.setAttribute("trade_no", trade_no);request.setAttribute("total_amount", total_amount);System.out.println("订单处理：系统订单号" + out_trade_no + "支付宝交易号：" + trade_no);//系统处理根据支付宝回调更改订单状态或者其他关联表的数据/*  OrderInfo order = payService.findOneByTradeCode(out_trade_no);if(order == null){signVerified = false;request.setAttribute("signVerified", signVerified);request.setAttribute("reason", "商户订单号不存在");System.out.println("系统订单："+ out_trade_no + "不存在。");}else{if(!order.getMoney().toString().equals(total_amount)){signVerified = false;request.setAttribute("signVerified", signVerified);request.setAttribute("reason", "付款金额不对");return "notify_url";}if(order.getTradeStatus() == 1){//判断当前订单是否已处理，避免重复处理log.info("系统订单："+ out_trade_no + "无需重复处理。");}else{order.setTradeStatus(1);//修改订单状态为已支付Date payedAt = new Date();order.setTransactionId(trade_no);order.setPayedAt(payedAt);payService.payOrder(order);System.out.println("系统订单："+ out_trade_no + "成功支付。");}}
*/}else{request.setAttribute("reason", "验签失败");}request.setAttribute("signVerified", signVerified);return "return_url";}/*** 异步回调路径 notify_url* @param request* @param response* @throws AlipayApiException* @throws*/@RequestMapping("notify_url.view")public void notify_url(HttpServletRequest request, HttpServletResponse response) throws AlipayApiException, IOException {System.out.println("调用 异步 回调");//获取支付宝POST过来反馈信息Map<String,String> params = new HashMap<String,String>();Map requestParams = request.getParameterMap();for (Iterator iter = requestParams.keySet().iterator(); iter.hasNext();) {String name = (String) iter.next();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] + ",";}//乱码解决，这段代码在出现乱码时使用。//valueStr = new String(valueStr.getBytes("ISO-8859-1"), "utf-8");params.put(name, valueStr);}//切记alipaypublickey是支付宝的公钥，请去open.alipay.com对应应用下查看。//boolean AlipaySignature.rsaCheckV1(Map<String, String> params, String publicKey, String charset, String sign_type)boolean signVerified = AlipaySignature.rsaCheckV1(params, AlipayConfig.alipay_public_key, AlipayConfig.charset,AlipayConfig.sign_type);if(signVerified) {//商户订单号String out_trade_no = new String(request.getParameter("out_trade_no").getBytes("ISO-8859-1"),"UTF-8");//支付宝交易号String trade_no = new String(request.getParameter("trade_no").getBytes("ISO-8859-1"),"UTF-8");//付款金额String total_amount = new String(request.getParameter("total_amount").getBytes("ISO-8859-1"),"UTF-8");request.setAttribute("out_trade_no", out_trade_no);request.setAttribute("trade_no", trade_no);request.setAttribute("total_amount", total_amount);System.out.println("订单处理：系统订单号" + out_trade_no + "支付宝交易号：" + trade_no);//系统处理根据支付宝回调更改订单状态或者其他关联表的数据/*  OrderInfo order = payService.findOneByTradeCode(out_trade_no);if(order == null){signVerified = false;request.setAttribute("signVerified", signVerified);request.setAttribute("reason", "商户订单号不存在");System.out.println("系统订单："+ out_trade_no + "不存在。");}else{if(!order.getMoney().toString().equals(total_amount)){signVerified = false;request.setAttribute("signVerified", signVerified);request.setAttribute("reason", "付款金额不对");return "notify_url";}if(order.getTradeStatus() == 1){//判断当前订单是否已处理，避免重复处理log.info("系统订单："+ out_trade_no + "无需重复处理。");}else{order.setTradeStatus(1);//修改订单状态为已支付Date payedAt = new Date();order.setTransactionId(trade_no);order.setPayedAt(payedAt);payService.payOrder(order);System.out.println("系统订单："+ out_trade_no + "成功支付。");}}
*/}else{request.setAttribute("reason", "验签失败");}request.setAttribute("signVerified", signVerified);response.setContentType("text/html;charset=" + AlipayConfig.charset);response.getWriter().write("success");//直接将完整的表单html输出到页面response.getWriter().flush();response.getWriter().close();}}

 4 启动服务  访问  localhost:8080/pay   会直接支付宝支付页面  

然后使用 沙箱版支付宝  登录买家账号 进行扫码支付  下载连接  https://openhome.alipay.com/platform/appDaily.htm?tab=info

Appid  买家账号 可以参考 上篇文章 进行申请 （https://blog.csdn.net/qq_34789780/article/details/103985710）

 支付成功后  会自动调用  同步和异步 回调接口

  异步回调接口 必须外网可以访问  否则不会调用   在 AlipayConfig 中进行配置