微信支付apiV3异常：The corresponding provider for the merchant already exists

异常信息

java.lang.IllegalStateException: The corresponding provider for the merchant already exists.

原因

这个错误是微信SDK抛出的，这是因为微信支付apiV3的RSAConfig重复build导致，即RSAConfig要保证是单例才不会导致报错。

// 要保证这个Config在服务中单例
private RSAAutoCertificateConfig config;

@Autowired
public void setConfig(){
    config = new RSAAutoCertificateConfig.Builder()
            .merchantId(mchId)
            .privateKey(privateKey)
            .merchantSerialNumber(mchSerialNo)
                    .apiV3Key(apiV3Key)
                            .build();
}

public Config getConfig(){
    return this.config;
}

public NotificationConfig getNotificationConfig(){
    return this.config;
}

参数说明

• mchId：商户号
• privateKey：商户号密钥
• mchSerialNo：商户证书号
• apiV3Key：apiV3密钥

建议

可以把商户配置参数使用数据库保存，服务启动的时候加载在缓存里面，缓存的key为mchId，value为config对象，这样可以实现一个服务多个直连商户号共存。

package com.swkj.payment.test;

import com.swkj.common.base.enums.PaymentMchType;
import com.swkj.common.base.util.CollectionUtils;
import com.swkj.common.charge.model.po.paymentmch.PaymentMchPo;
import com.swkj.common.charge.service.paymentmch.PaymentMchService;
import com.swkj.common.core.wrapper.LambdaQueryWrapperX;
import com.wechat.pay.java.core.Config;
import com.wechat.pay.java.core.RSAAutoCertificateConfig;
import com.wechat.pay.java.core.notification.NotificationConfig;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;

/**
 * @Description:
 * @Author: GE LIANG
 * @Date: 2023/3/14 8:49
 */
public class PaymentServiceImpl {



    // 本地缓存
    private Map<String, RSAAutoCertificateConfig> configMap;

    @Resource
    PaymentMchService paymentMchService;

    @PostConstruct
    public void initConfig() {
        LambdaQueryWrapperX<PaymentMchPo> wrapperX = new LambdaQueryWrapperX<>();
        wrapperX.eq(PaymentMchPo::getMchTypeId, PaymentMchType.WECHAT.getValue());
        List<PaymentMchPo> list = paymentMchService.list(wrapperX);
        if (CollectionUtils.isEmpty(list)) {
            return;
        }
        for (PaymentMchPo paymentMchPo : list) {
            RSAAutoCertificateConfig config =
                    new RSAAutoCertificateConfig.Builder()
                            .merchantId(paymentMchPo.getMchId())
                            .privateKey(paymentMchPo.getPrivateKey())
                            // .privateKeyFromPath(wechatPaymentConfig.getPrivateKeyPath())
                            .merchantSerialNumber(paymentMchPo.getMchSerialNo())
                            .apiV3Key(paymentMchPo.getApiV3Key())
                            .build();
            configMap.put(paymentMchPo.getAppId(), config);
        }
    }


    /**
     * @param appId 根据AppId获取Config
     * @return
     */
    public Config getWechatConfig(String appId) {
        return configMap.get(appId);
    }

    /**
     * @param appId 根据appId获取NotificationConfig
     * @return
     */
    public NotificationConfig getNotificationConfig(String appId) {
        return configMap.get(appId);
    }
}

PaymentMchPo 对应的sql结构文章来源地址https://uudwc.com/A/DzOgr

DROP TABLE IF EXISTS "public"."charge_payment_mch";
CREATE TABLE "public"."charge_payment_mch" (
  "payment_mch_id" int8 NOT NULL,
  "revision" int4 NOT NULL,
  "created_by" int8 NOT NULL,
  "created_time" timestamp(0) NOT NULL,
  "updated_by" int8,
  "updated_time" timestamp(0),
  "mch_id" varchar(50) COLLATE "pg_catalog"."default",
  "private_key" text COLLATE "pg_catalog"."default",
  "mch_serial_no" varchar(256) COLLATE "pg_catalog"."default",
  "api_v3_key" varchar(256) COLLATE "pg_catalog"."default",
  "app_id" varchar(50) COLLATE "pg_catalog"."default"
)
;