sdk依赖

        <dependency>
            <groupId>com.alipay.sdk</groupId>
            <artifactId>alipay-sdk-java</artifactId>
            <version>4.8.10.ALL</version>
        </dependency>

支付宝好处就是有沙箱测试,可以去下载沙箱钱包
沙箱环境
支付宝客户端调试工具可下载测试使用,注意应用公钥和支付宝公钥是不一样的,
基础配置，具体参数需去申请app支付
密钥生成器 下载
官方文档

package com.hanfu.payment.center.config;

import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.hanfu.payment.center.dao.PayBossMapper;
import com.hanfu.payment.center.model.PayBossExample;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

/**
 * 支付宝支付的参数配置
 *
 * @author shihao
 */
@Component
@ConfigurationProperties()
public class AlipayConfig {
    /**
     * 支付宝gatewayUrl
     */
    private String gatewayUrl = "https://openapi.alipay.com/gateway.do";
    /**
     * 商户应用id
     */

    private String appid = "商户应用id";
    /**
     * RSA私钥，用于对商户请求报文加签
     */
   private String appPrivateKey = "RSA私钥";
    /**
     * 支付宝RSA公钥，用于验签支付宝应答
     */
    private String alipayPublicKey = "支付宝RSA公钥";
    /**
     * 签名类型
     */
    private String signType = "RSA2";
    /**
     * 格式
     */
    private String formate = "json";
    /**
     * 编码
     */
    private String charset = "UTF-8";
    /**
     * 同步地址
     */
    private String returnUrl;
    /**
     * 异步地址
     */
    private String notifyUrl = "";
    /**
     * 最大查询次数
     */
    private static int maxQueryRetry = 5;
    /**
     * 查询间隔（毫秒）
     */
    private static long queryDuration = 5000;
    /**
     * 最大撤销次数
     */
    private static int maxCancelRetry = 3;
    /**
     * 撤销间隔（毫秒）
     */
    private static long cancelDuration = 3000;

    public String getGatewayUrl() {
        return gatewayUrl;
    }

    public void setGatewayUrl(String gatewayUrl) {
        this.gatewayUrl = gatewayUrl;
    }

    public String getAppid() {

        return appid ;
    }

    public void setAppid(String appid) {
        this.appid = appid;
    }

    public String getAppPrivateKey() {
        return appPrivateKey ;
    }

    public void setAppPrivateKey(String appPrivateKey) {
        this.appPrivateKey = appPrivateKey;
    }

    public String getAlipayPublicKey() {
        return alipayPublicKey;
    }

    public void setAlipayPublicKey(String alipayPublicKey) {
        this.alipayPublicKey = alipayPublicKey;
    }

    public String getSignType() {
        return signType;
    }

    public void setSignType(String signType) {
        this.signType = signType;
    }

    public String getFormate() {
        return formate;
    }

    public void setFormate(String formate) {
        this.formate = formate;
    }

    public String getCharset() {
        return charset;
    }

    public void setCharset(String charset) {
        this.charset = charset;
    }

    public String getReturnUrl() {
        return returnUrl;
    }

    public void setReturnUrl(String returnUrl) {
        this.returnUrl = returnUrl;
    }

    public String getNotifyUrl() {
        return notifyUrl;
    }

    public void setNotifyUrl(String notifyUrl) {
        this.notifyUrl = notifyUrl;
    }

    public static int getMaxQueryRetry() {
        return maxQueryRetry;
    }

    public static void setMaxQueryRetry(int maxQueryRetry) {
        AlipayConfig.maxQueryRetry = maxQueryRetry;
    }

    public static long getQueryDuration() {
        return queryDuration;
    }

    public static void setQueryDuration(long queryDuration) {
        AlipayConfig.queryDuration = queryDuration;
    }

    public static int getMaxCancelRetry() {
        return maxCancelRetry;
    }

    public static void setMaxCancelRetry(int maxCancelRetry) {
        AlipayConfig.maxCancelRetry = maxCancelRetry;
    }

    public static long getCancelDuration() {
        return cancelDuration;
    }

    public static void setCancelDuration(long cancelDuration) {
        AlipayConfig.cancelDuration = cancelDuration;
    }
}

service

package com.hanfu.payment.center.AppPaymentService;

import com.alipay.api.AlipayApiException;
import com.hanfu.payment.center.tool.ResultMap;


import javax.servlet.http.HttpServletRequest;

/**
 * 支付宝服务接口
 *
 * Author:shihao
 * Date:2020/8/1
 * Description:
 */
public interface AlipayService {

    /**
     * @Description: 创建支付宝订单
     * @param orderNo: 订单编号
     * @param amount: 实际支付金额
     * @param body: 订单描述
     * @Author:shihao
     * @Date: 2020/8/1
     * @return
     */
    String createOrder(String orderNo, double amount, String body) throws AlipayApiException;

    /**
     * @Description:
     * @param tradeStatus: 支付宝交易状态
     * @param orderNo: 订单编号
     * @param tradeNo: 支付宝订单号
     * @Author:
     * @Date: 2020/8/1
     * @return
     */
    boolean notify(String tradeStatus, String orderNo, String tradeNo);

    /**
     * @Description: 校验签名
     * @param request
     * @Author:
     * @Date: 2020/8/1
     * @return
     */
    boolean rsaCheckV1(HttpServletRequest request);

    /**
     * @Description: 退款
     * @param orderNo : 订单编号
     * @param amount : 实际支付金额
     * @param refundReason : 退款原因
     * @Author: shihao
     * @Date: 2020/8/6
     * @return
     */
    ResultMap refund(String orderNo, double amount, String refundReason);
}

实现类

package com.hanfu.payment.center.AppPaymentService.impl;


import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.alipay.api.domain.AlipayTradeAppPayModel;
import com.alipay.api.domain.AlipayTradeRefundModel;
import com.alipay.api.internal.util.AlipaySignature;
import com.alipay.api.request.AlipayTradeAppPayRequest;
import com.alipay.api.request.AlipayTradeRefundRequest;
import com.alipay.api.response.AlipayTradeAppPayResponse;
import com.alipay.api.response.AlipayTradeRefundResponse;
import com.hanfu.payment.center.AppPaymentService.AlipayService;
import com.hanfu.payment.center.config.AlipayConfig;
import com.hanfu.payment.center.tool.ResultMap;
import io.micrometer.core.instrument.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * Author:shihao
 * Date:2020/8/1
 * Description:
 */
@Service
public class AlipayServiceImpl implements AlipayService {
    private final Logger logger = LoggerFactory.getLogger(com.hanfu.payment.center.service.impl.AlipayServiceImpl.class);

    @Autowired
    private AlipayConfig alipayConfig;
//    @Autowired
//    private AlipayClient alipayClient;

    @Override
    public String createOrder(String orderNo, double amount, String body) throws AlipayApiException {

        AlipayClient alipayClient = new DefaultAlipayClient(alipayConfig.getGatewayUrl(), alipayConfig.getAppid(), alipayConfig.getAppPrivateKey(),
                alipayConfig.getFormate(), alipayConfig.getCharset(),alipayConfig.getAlipayPublicKey(),alipayConfig.getSignType());


        //SDK已经封装掉了公共参数，这里只需要传入业务参数。以下方法为sdk的model入参方式(model和biz_content同时存在的情况下取biz_content)。
        AlipayTradeAppPayModel model = new AlipayTradeAppPayModel();
        model.setSubject(body);
        model.setOutTradeNo(orderNo);
        System.out.println("支付:"+amount/100+"元");//数据库是分支付宝是元所以除100
        model.setTotalAmount(String.valueOf(amount/100));
        model.setProductCode("QUICK_MSECURITY_PAY");
        model.setPassbackParams("公用回传参数，如果请求时传递了该参数，则返回给商户时会回传该参数");

        //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.app.pay
        AlipayTradeAppPayRequest ali_request = new AlipayTradeAppPayRequest();
        ali_request.setBizModel(model);
        ali_request.setNotifyUrl(alipayConfig.getNotifyUrl());// 回调地址
        AlipayTradeAppPayResponse ali_response = alipayClient.sdkExecute(ali_request);
        //就是orderString 可以直接给客户端请求，无需再做处理。
        return ali_response.getBody();
    }

    @Override
    public boolean notify(String tradeStatus, String orderNo, String tradeNo) {
        if ("TRADE_FINISHED".equals(tradeStatus)
                || "TRADE_SUCCESS".equals(tradeStatus)) {
            // 支付成功，根据业务逻辑修改相应数据的状态
            // boolean state = orderPaymentService.updatePaymentState(orderNo, tradeNo);
//            if (state) {
//                return true;
//            }
            return true;
        }
        return false;
    }

    @Override
    public boolean rsaCheckV1(HttpServletRequest request){
        try {
            Map<String, String> params = new HashMap<>();
            Map<String, String[]> requestParams = request.getParameterMap();
            for (Iterator iter = requestParams.keySet().iterator(); iter.hasNext(); ) {
                String name = (String) iter.next();
                String[] values = 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 verifyResult = AlipaySignature.rsaCheckV1(params, alipayConfig.getAlipayPublicKey(), alipayConfig.getCharset(), alipayConfig.getSignType());
            return verifyResult;
        } catch (AlipayApiException e) {
            logger.debug("verify sigin error, exception is:{}", e);
            return false;
        }
    }

    @Override
    public ResultMap refund(String orderNo, double amount, String refundReason) {
        if(StringUtils.isBlank(orderNo)){
            return ResultMap.error("订单编号不能为空");
        }
        if(amount <= 0){
            return ResultMap.error("退款金额必须大于0");
        }
        AlipayClient alipayClient = new DefaultAlipayClient(alipayConfig.getGatewayUrl(), alipayConfig.getAppid(), alipayConfig.getAppPrivateKey(),
                alipayConfig.getFormate(), alipayConfig.getCharset(),alipayConfig.getAlipayPublicKey(),alipayConfig.getSignType());
        AlipayTradeRefundModel model=new AlipayTradeRefundModel();
        // 商户订单号
        model.setOutTradeNo(orderNo);
        // 退款金额
        model.setRefundAmount(String.valueOf(amount));
        // 退款原因
        model.setRefundReason(refundReason);
        // 退款订单号(同一个订单可以分多次部分退款，当分多次时必传)
        // model.setOutRequestNo(UUID.randomUUID().toString());
        AlipayTradeRefundRequest alipayRequest = new AlipayTradeRefundRequest();
        alipayRequest.setBizModel(model);
        AlipayTradeRefundResponse alipayResponse = null;
        try {
            alipayResponse = alipayClient.execute(alipayRequest);
        } catch (AlipayApiException e) {
            logger.error("订单退款失败，异常原因:{}", e);
        }
        if(alipayResponse != null){
            String code = alipayResponse.getCode();
            String subCode = alipayResponse.getSubCode();
            String subMsg = alipayResponse.getSubMsg();
            if("10000".equals(code)
                    && StringUtils.isBlank(subCode)
                    && StringUtils.isBlank(subMsg)){
                // 表示退款申请接受成功，结果通过退款查询接口查询
                // 修改用户订单状态为退款
                return ResultMap.ok("订单退款成功");
            }
            return ResultMap.error(subCode + ":" + subMsg);
        }
        return ResultMap.error("订单退款失败");
    }
}

异步回调

/**
     * 支付异步通知
     * 接收到异步通知并验签通过后，一定要检查通知内容，
     * 包括通知中的app_id、out_trade_no、total_amount是否与请求中的一致，并根据trade_status进行后续业务处理。
     * https://docs.open.alipay.com/194/103296
     */
    @RequestMapping("/notify")
    public String notify(HttpServletRequest request) {
        System.out.println("异步回调");
        // 验证签名
        boolean flag = alipayService.rsaCheckV1(request);
        if (flag) {
            String tradeStatus = request.getParameter("trade_status"); // 交易状态
            String outTradeNo = request.getParameter("out_trade_no"); // 商户订单号
            String tradeNo = request.getParameter("trade_no"); // 支付宝订单号
            /**
             * 还可以从request中获取更多有用的参数，自己尝试
             */
            boolean notify = alipayService.notify(tradeStatus, outTradeNo, tradeNo);
            if(notify){
                return "success";
            }
        }
        return "fail";
    }

前端方面和之前的微信差不多,换掉一些参数即可具体可查看uniapp官方文档