Java实现微信小程序V3支付 (完整demo)

1. 小程序>微信小程序支付-开发者文档https://pay.weixin.qq.com/wiki/doc/apiv3/apis/chapter3_5_1.shtml

2. 导入依赖

<!--小程序支付 v3-->
<dependency>
	<groupId>com.github.wechatpay-apiv3</groupId>
	<artifactId>wechatpay-apache-httpclient</artifactId>
	<version>0.4.9</version>
</dependency>

3. 微信支付工具类

import com.wechat.pay.contrib.apache.httpclient.util.PemUtil;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.PrivateKey;

/**
 * 微信支付工具类
 */
@Component
public class WxPayUtils {

    // 商户号
    public static final String mchId = "xxxxxxx";
    // AppID(小程序ID)
    public static final String appId = "xxxxxxx";
    // AppSecret(小程序密钥)
    public static final String appSecret = "xxxxxxx";
    // 授权
    public final static String grantType = "authorization_code";
    // APIv3密钥
    public final static String apiV3Key = "xxxxxxx";
    // 证书序列号 (从p12文件解析)
    public final static String serialnumber = "xxxxxxx";


    // 证书私钥
    public static final String privateKey = "xxxxxxx";


    /**
     * 获取私钥。
     */
    public static PrivateKey getPrivateKey() throws IOException {
        PrivateKey merchantPrivateKey = PemUtil.loadPrivateKey(
                new ByteArrayInputStream(privateKey.getBytes("utf-8")));
        return merchantPrivateKey;
    }
}

4. 微信支付URL工具类

public interface ConstantUtils {


    // JSAPI下单
    public final static String JSAPI_URL = "https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi";
    // 支付通知
    public final static String NOTIFY_URL = "https://你的线上地址.com";
    // 关闭订单
    public final static String CLOSE_PAY_ORDER_URL = "https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/{out_trade_no}/close";
    // 查询订单 (根据商户订单号查询)
    public final static String QUERY_PAY_RESULT_URL = "https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/";
}

5. 微信支付API v3 HttpClient (自动处理签名和验签)

import com.wechat.pay.contrib.apache.httpclient.WechatPayHttpClientBuilder;
import com.wechat.pay.contrib.apache.httpclient.auth.PrivateKeySigner;
import com.wechat.pay.contrib.apache.httpclient.auth.Verifier;
import com.wechat.pay.contrib.apache.httpclient.auth.WechatPay2Credentials;
import com.wechat.pay.contrib.apache.httpclient.auth.WechatPay2Validator;
import com.wechat.pay.contrib.apache.httpclient.cert.CertificatesManager;
import com.wechat.pay.contrib.apache.httpclient.exception.HttpCodeException;
import com.wechat.pay.contrib.apache.httpclient.exception.NotFoundException;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.impl.client.CloseableHttpClient;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;


@Slf4j
@Component
@Order(3)
public class WechatPayaHttpclientUtils implements ApplicationRunner {

     // 商户API私钥
     public static PrivateKey merchantPrivateKey;
     // verifier
     public static Verifier verifier;
     // httpClient
     public static CloseableHttpClient httpClient;


    @Override
    public void run(ApplicationArguments args) {
        log.info("----------->构造微信支付API v3 HttpClient");
        createHttpClient();
    }


    /***
     * 微信支付API v3 HttpClient
     *
     * 自动处理签名和验签
     *
     * @return
     */
    public void createHttpClient() {
        try {

            merchantPrivateKey = WxPayUtils.getPrivateKey();
        } catch (Exception e) {
            e.printStackTrace();
        }
        // 获取证书管理器实例
        CertificatesManager certificatesManager = CertificatesManager.getInstance();
        try {
            // 向证书管理器增加需要自动更新平台证书的商户信息
            certificatesManager.putMerchant(WxPayUtils.mchId, new WechatPay2Credentials(WxPayUtils.mchId,
                    new PrivateKeySigner(WxPayUtils.serialnumber, merchantPrivateKey)), WxPayUtils.apiV3Key.getBytes(StandardCharsets.UTF_8));
            // ... 若有多个商户号，可继续调用putMerchant添加商户信息
        } catch (IOException e) {
            e.printStackTrace();
        } catch (GeneralSecurityException e) {
            e.printStackTrace();
        } catch (HttpCodeException e) {
            e.printStackTrace();
        }
        try {
            // 从证书管理器中获取verifier
            verifier = certificatesManager.getVerifier(WxPayUtils.mchId);
        } catch (NotFoundException e) {
            e.printStackTrace();
        }
        WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create()
                .withMerchant(WxPayUtils.mchId, WxPayUtils.serialnumber, merchantPrivateKey)
                .withValidator(new WechatPay2Validator(verifier));
        // ... 接下来，你仍然可以通过builder设置各种参数，来配置你的HttpClient

        // 通过WechatPayHttpClientBuilder构造的HttpClient，会自动的处理签名和验签
        httpClient = builder.build();
    }
}

6. controller

import com.ruoyi.common.core.controller.BaseController;
import com.ruoyi.common.core.domain.AjaxResult;
import com.ruoyi.ruoyils.sy.order.domain.LsOrder;
import com.ruoyi.ruoyils.wx.pay.service.IWxPayService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Slf4j
@Api(value = "微信-支付", tags = {"微信-支付"})
@RestController
@RequestMapping("/ls/wx/pay")
public class WxPayController extends BaseController {

    @Autowired
    private IWxPayService wxPayService;


    /**
     * jsapi下单
     *
     * @param lsOrder   订单
     * @return
     */
    @ApiOperation("统一下单")
    @PostMapping(value = "/payment")
    public AjaxResult payment(@RequestBody LsOrder lsOrder) {
        return wxPayService.addOrder(lsOrder);
    }


    /**
     * 支付通知
     *
     * @param request
     * @param response
     * @return
     */
    @GetMapping("/notifyUrl")
    public AjaxResult notifyUrl(HttpServletRequest request, HttpServletResponse response) {
        return AjaxResult.success(wxPayService.notifyUrl(request, response));
    }

}

7. service


import cn.hutool.core.util.ObjectUtil;
import cn.hutool.http.ContentType;
import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.ruoyi.common.core.domain.AjaxResult;
import com.ruoyi.common.utils.DateUtils;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.common.utils.sign.Base64;
import com.ruoyi.common.utils.spring.SpringUtils;
import com.ruoyi.ruoyils.exception.MyException;
import com.ruoyi.ruoyils.sy.append.domain.LsAppend;
import com.ruoyi.ruoyils.sy.append.mapper.LsAppendMapper;
import com.ruoyi.ruoyils.sy.order.domain.LsOrder;
import com.ruoyi.ruoyils.sy.order.mapper.LsOrderMapper;
import com.ruoyi.ruoyils.sy.order.service.impl.LsOrderServiceImpl;
import com.ruoyi.ruoyils.sy.product.domain.LsProduct;
import com.ruoyi.ruoyils.sy.product.mapper.LsProductMapper;
import com.ruoyi.ruoyils.utils.*;
import com.ruoyi.ruoyils.wx.pay.service.IWxPayService;
import com.ruoyi.ruoyils.wx.user.domain.LsUser;
import com.ruoyi.ruoyils.wx.user.mapper.LsUserMapper;
import com.wechat.pay.contrib.apache.httpclient.auth.Verifier;
import com.wechat.pay.contrib.apache.httpclient.notification.Notification;
import com.wechat.pay.contrib.apache.httpclient.notification.NotificationHandler;
import com.wechat.pay.contrib.apache.httpclient.notification.NotificationRequest;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.util.EntityUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.annotation.Order;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.nio.charset.StandardCharsets;
import java.security.Signature;
import java.util.*;

@Order(5)
@Slf4j
@Service
public class WxPayServiceImpl implements IWxPayService {

    @Autowired
    private LsOrderMapper orderMapper;
    @Autowired
    private LsUserMapper lsUserMapper;
    @Autowired
    private LsProductMapper lsProductMapper;
    @Autowired
    private LsAppendMapper lsAppendMapper;


    /**
     * 立即下单
     *
     * @param lsOrder 订单
     * @return 结果
     */
    @Transactional(rollbackFor = Exception.class)
    @Override
    public AjaxResult addOrder(LsOrder lsOrder) {

            // TODO 订单业务操作

            // 生成订单
            int i = orderMapper.insertLsOrder(lsOrder);
            if (i > 0) {
                // 调起支付
                AjaxResult payment = this.payment(lsOrder);
                return payment;
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        }
        return AjaxResult.error("下单失败 !");
    }


    /**
     * 调起支付
     *
     * @param lsOrder
     * @return
     */

    @Override
    public AjaxResult payment(LsOrder lsOrder) {
        try {
            JSONObject order = new JSONObject();
            // 应用ID
            order.put("appid",WxPayUtils.appId);
            // 商户号
            order.put("mchid",WxPayUtils.mchId);
            // 商品描述
            order.put("description",lsOrder.getProductName());
            // 订单号
            order.put("out_trade_no",lsOrder.getOrderNo());
            // 通知地址
            order.put("notify_url",ConstantUtils.NOTIFY_URL+"/ls/wx/pay/notifyUrl");
            /**订单金额*/
            JSONObject amount = new JSONObject();
            // 总金额 (默认单位分)
//            amount.put("total",lsOrder.getTotalPrice().intValue()*100);
            amount.put("total",1);
            // 货币类型
            amount.put("currency","CNY");
            order.put("amount",amount);

            /**支付者*/
            JSONObject payer = new JSONObject();
            LsUser user = SpringUtils.getBean(LsUserMapper.class).selectLsUserById(lsOrder.getUserId());
            // 用户标识
            payer.put("openid",user.getOpenid());
            order.put("payer",payer);

            // 微信httpClient
            CloseableHttpClient httpClient = WechatPayaHttpclientUtils.httpClient;
            if (httpClient == null) {
                log.info("预下单请求失败");
                return AjaxResult.error("预下单失败，请重试,无法连接微信支付服务器!");
            }

            HttpPost httpPost = new HttpPost(ConstantUtils.JSAPI_URL);
            httpPost.addHeader("Accept", "application/json");
            httpPost.addHeader("Content-type","application/json; charset=utf-8");
            httpPost.setEntity(new StringEntity(order.toJSONString(), "UTF-8"));
            // 后面跟使用Apache HttpClient一样
            CloseableHttpResponse response = httpClient.execute(httpPost);
            String bodyAsString = EntityUtils.toString(response.getEntity());

            JSONObject bodyAsJSON = JSONObject.parseObject(bodyAsString);
            String message = bodyAsJSON.getString("message");
            // 返回code, 说明请求失败
            if (bodyAsJSON.containsKey("code")) {
                log.info("预下单请求失败{}", message);
                return AjaxResult.error("预下单失败，请重试！" + message);
            }

            // 返回预支付id
            final String prepay_id = bodyAsJSON.getString("prepay_id");
            if (StringUtils.isEmpty(prepay_id)) {
                log.info("预下单请求失败{}", message);
                return AjaxResult.error("预下单失败，请重试！" + message);
            }

            LsOrder preOrder = new LsOrder();
            preOrder.setId(lsOrder.getId());
            preOrder.setPrepayId(prepay_id);
            orderMapper.updateLsOrder(preOrder);

            // JSAPI调起支付API: 此API无后台接口交互，需要将列表中的数据签名
            // 随机字符串
            final String nonceStr = RandomNumberUtils.getRandomString(32,false);
            // 时间戳
            String timeStamp = String.valueOf(System.currentTimeMillis());
            /*签名*/
            StringBuilder sb = new StringBuilder();
            sb.append(WxPayUtils.appId + "\n"); //小程序appId
            sb.append(timeStamp + "\n"); //时间戳
            sb.append(nonceStr + "\n"); //随机字符串
            sb.append("prepay_id=" + prepay_id + "\n"); //订单详情扩展字符串
            Signature signature = Signature.getInstance("SHA256withRSA");
            signature.initSign(WechatPayaHttpclientUtils.merchantPrivateKey);
            signature.update(sb.toString().getBytes("UTF-8"));
            byte[] signBytes = signature.sign();
            String paySign = Base64.encode(signBytes);

            JSONObject params = new JSONObject();
            params.put("appId", WxPayUtils.appId);
            params.put("timeStamp", timeStamp);
            params.put("nonceStr", nonceStr);
            params.put("package", "prepay_id="+prepay_id);
            params.put("signType", "RSA");
            params.put("paySign", paySign);

            return AjaxResult.success(params);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return AjaxResult.error("预下单失败，请重试！");
    }

    /**
     * 支付通知
     *
     * @param servletRequest
     * @param response
     * @return
     */
    @Override
    public AjaxResult notifyUrl(HttpServletRequest servletRequest, HttpServletResponse response) {
        log.info("----------->微信支付回调开始<-----------");
        Map<String, String> map = new HashMap<>(12);
        String timeStamp = servletRequest.getHeader("Wechatpay-Timestamp");
        String nonce = servletRequest.getHeader("Wechatpay-Nonce");
        String signature = servletRequest.getHeader("Wechatpay-Signature");
        String certSn = servletRequest.getHeader("Wechatpay-Serial");
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(servletRequest.getInputStream()))) {
            StringBuilder stringBuilder = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                stringBuilder.append(line);
            }
            String obj = stringBuilder.toString();
            log.info("支付回调请求参数:{},{},{},{},{}", obj, timeStamp, nonce, signature, certSn);

            // 从证书管理器中获取verifier
            Verifier verifier = WechatPayaHttpclientUtils.verifier;

            String sn = verifier.getValidCertificate().getSerialNumber().toString(16).toUpperCase(Locale.ROOT);
            NotificationRequest request = new NotificationRequest.Builder().withSerialNumber(sn)
                    .withNonce(nonce)
                    .withTimestamp(timeStamp)
                    .withSignature(signature)
                    .withBody(obj)
                    .build();
            NotificationHandler handler = new NotificationHandler(verifier, WxPayUtils.apiV3Key.getBytes(StandardCharsets.UTF_8));
            // 验签和解析请求体
            Notification notification = handler.parse(request);
            JSONObject bodyAsJSON = JSON.parseObject(notification.getDecryptData());
            log.info("支付回调响应参数: {}", bodyAsJSON.toJSONString());
            //做一些操作
            if (bodyAsJSON != null) {
                //如果支付成功
                String tradeState = bodyAsJSON.getString("trade_state");
                if("SUCCESS".equals(tradeState)){
                    //拿到商户订单号
                    String outTradeNo = bodyAsJSON.getString("out_trade_no");
                    JSONObject amountJson = bodyAsJSON.getJSONObject("amount");
                    Integer payerTotal = amountJson.getInteger("payer_total");
                    LsOrder order = orderMapper.selectLsOrderByOrderNo(outTradeNo);
                    if(order != null){
                        if(order.getStatus() == 1){
                            //如果支付状态为1 说明订单已经支付成功了,直接响应微信服务器返回成功
                            response.setStatus(200);
                            map.put("code", "SUCCESS");
                            map.put("message", "SUCCESS");
                            response.setHeader("Content-type", ContentType.JSON.toString());
                            response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
                            response.flushBuffer();
                        }
                        //验证用户支付的金额和订单金额是否一致
                        if(payerTotal.equals(order.getTotalPrice())){
                            //修改订单状态
                            String successTime = bodyAsJSON.getString("success_time");
                            order.setStatus(1);
                            order.setPaymentTime(DateUtils.rfcToDate(successTime));
                            orderMapper.updateLsOrder(order);
                            //响应微信服务器
                            response.setStatus(200);
                            map.put("code", "SUCCESS");
                            map.put("message", "SUCCESS");
                            response.setHeader("Content-type", ContentType.JSON.toString());
                            response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
                            response.flushBuffer();
                        }
                    }
                }
            }
            response.setStatus(500);
            map.put("code", "FAIL");
            map.put("message", "签名错误");
            response.setHeader("Content-type", ContentType.JSON.toString());
            response.getOutputStream().write(JSONUtil.toJsonStr(map).getBytes(StandardCharsets.UTF_8));
            response.flushBuffer();
        } catch (Exception e) {
            log.error("微信支付回调失败", e);
        }
        return AjaxResult.error("微信支付回调失败");
    }

    /**
     * 关闭订单
     *
     * @param orderNo
     * @return
     */
    public boolean closePayOrder(String orderNo) {
        JSONObject obj = new JSONObject();
        // 直连商户号
        obj.put("mchid", WxPayUtils.mchId);
        // 请求地址
        String closeOrderUrl = ConstantUtils.CLOSE_PAY_ORDER_URL.replace("{out_trade_no}", orderNo);

        HttpPost httpPost = new HttpPost(closeOrderUrl);
        httpPost.addHeader("Accept", "application/json");
        httpPost.addHeader("Content-type", "application/json; charset=utf-8");
        httpPost.setEntity(new StringEntity(obj.toJSONString(), "UTF-8"));

        // 微信httpClient
        CloseableHttpClient httpClient = WechatPayaHttpclientUtils.httpClient;
        try {
            if(httpClient == null){
                log.info("关闭订单失败，请重试,无法连接微信支付服务器!");
            }
            //执行请求
            CloseableHttpResponse response = httpClient.execute(httpPost);
            //状态码
            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode == 204) {
                //关闭订单成功!
                log.info("微信关闭订单成功: {}", orderNo);
            }else if(statusCode == 202){
                //用户支付中，需要输入密码
                log.info("关闭微信订单--用户支付中，需要输入密码,暂时不做处理!");
            }else{
                log.info("关闭微信订单--关闭支付订单失败，出现未知原因: {}", EntityUtils.toString(response.getEntity()));
            }
        } catch (IOException e) {
            log.info("关闭微信订单--关闭订单失败: {}", e.getMessage());
        }
        return false;
    }

    /**
     * 订单查询 (定时查询订单, 修改订单状态)
     *
     * @return
     */
    @Scheduled(cron="0/10 * * * * ?")
    public void queryOrder() {

        LsOrder od = new LsOrder();
        od.setStatus(3); //未支付
        List<LsOrder> list = SpringUtils.getBean(LsOrderMapper.class).selectLsOrderList(od);
        if (CollectionUtils.isEmpty(list)) {
            return;
        }
        try {
            for (LsOrder lsOrder : list) {
                // 根据商户订单号查询
                URIBuilder uriBuilder = new URIBuilder(ConstantUtils.QUERY_PAY_RESULT_URL+lsOrder.getOrderNo());
                uriBuilder.setParameter("mchid", WxPayUtils.mchId);

                HttpGet httpGet = new HttpGet(uriBuilder.build());
                httpGet.addHeader("Accept", "application/json");

                CloseableHttpClient httpClient = WechatPayaHttpclientUtils.httpClient;
                if (httpClient == null) {
                    return;
                }
                CloseableHttpResponse response = httpClient.execute(httpGet);
                String bodyAsString = EntityUtils.toString(response.getEntity());
                JSONObject data = JSON.parseObject(bodyAsString);
                log.info("微信订单查询：{}", data);

                // 商户订单号
                String outTradeNo = data.getString("out_trade_no");
                // 交易状态 SUCCESS：支付成功, REFUND：转入退款, NOTPAY：未支付, CLOSED：已关闭
                String tradeState = data.getString("trade_state");
                // 支付完成时间
                String successTime = data.getString("success_time");
                Date date = DateUtils.rfcToDate(successTime);


                if (StringUtils.isNotEmpty(outTradeNo) && StringUtils.isNotEmpty(tradeState)) {
                    switch (tradeState) {
                        case "SUCCESS":
                            log.info("支付成功商户订单号: {}",outTradeNo);
                            lsOrder.setStatus(1);
                            lsOrder.setPaymentTime(date);
                            orderMapper.updateLsOrder(lsOrder);
                            break;
                        case "REFUND":
                            break;
                        case "NOTPAY":
                            // 查询订单未支付 截止时间是否超时
                            if (DateUtils.compareCurrentDateToEndDate(lsOrder.getNoPaymentCutoffTime())) {
                                lsOrder.setStatus(0);
                                if (orderMapper.updateLsOrder(lsOrder)>0) {
                                    // 微信关闭订单
                                    closePayOrder(lsOrder.getOrderNo());
                                }
                            }
                            break;
                        case "CLOSED":
                            log.info("已关闭商户订单号: {}",outTradeNo);
                            lsOrder.setStatus(0);
                            orderMapper.updateLsOrder(lsOrder);
                            break;
                    }
                } else {
                    log.info(data.getString("message"));
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

8. 返回给前端调起支付的必要参数

{
    "msg": "操作成功",
    "code": 200,
    "data": {
        "timeStamp": "1692334223808",
        "package": "prepay_id=wx18125024326178678d4e07673e277c0000",
        "paySign": "ocI64smXYkantoHEIkv7fibP0Y83pUmoVN1pQAjrJnFRI75sXCmQt09emPMhZJ+ujuemaGinJdJjmvGZv1JFoWvGSaMv8imDxOQV2EBr9QI+gybtUyC57+H2PhjXIR4gF0M8n7yv6Q9TA+7EIfpXOTaMJjDzM4AkFhAwz/quUAAEJVPLuaMsyF1xqi1qSY9AnE309YhqVG6ETDbZeP9/fuGCs9gD1HdD14HF4BndU696wR4TQdoiTzIyOokrE21oZLdK6Tp6sBPj2mGiIFX8viEHxq8GWOEMOIQXlr4NId4hrYA1Nn6xLk2Ka75t2t8L5V//3rWmbGSOaE5nrkeJcg==",
        "appId": "xxxxxxxxxxxxxx",
        "signType": "RSA",
        "nonceStr": "KFW6FBHHDMALH1A39FM07HKXM7I0T1GR"
    }
}