JAVA集成微信支付V3版JSAPI下单

一、引入微信支付SDK

<dependency><groupId>com.github.binarywang</groupId><artifactId>weixin-java-pay</artifactId>
</dependency>

二、支付参数封装

@Data
@ConfigurationProperties(prefix = "wx.pay")
public class WxPayProperties {/*** 微信公众号或者小程序等的appid*/private String appId;/*** 微信支付商户号*/private String mchId;/*** 微信支付商户密钥*/private String mchKey;/*** 服务商模式下的子商户公众账号ID*/private String subAppId;/*** 服务商模式下的子商户号*/private String subMchId;/*** apiclient_key.pem文件路径*/private String keyPath;/*** apiclient_cert.pem文件路径*/private String certPath;/*** 回调通知地址*/private String notifyUrl;/*** apiV3Key  */private String apiV3Key;}

三、调用微信预下单接口

1、支付业务参数封装

@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class PayRequestDTO {/*** 订单号*/private String   orderNo;/*** 支付金额*/private BigDecimal  totalFee;/*** 支付描述*/private String  body;/***  微信支付使用的用户标记*/private  String  openId;}

2、设置微信支付参数

@Autowired
private   WxPayProperties  wxPayProperties;public  WxPayConfig getWxConfig() {WxPayConfig wxPayConfig = new WxPayConfig();wxPayConfig.setAppId(wxPayProperties.getAppId());wxPayConfig.setMchId(wxPayProperties.getMchId()));wxPayConfig.setMchKey(wxPayProperties.getMchKey());wxPayConfig.setSubAppId(wxPayProperties.getSubAppId();wxPayConfig.setSubMchId(wxPayProperties.getSubMchId());wxPayConfig.setKeyPath(wxPayProperties.getKeyPath());wxPayConfig.setApiV3Key(wxPayProperties.getApiV3Key());wxPayConfig.setPrivateKeyPath(wxPayProperties.getKeyPath());wxPayConfig.setPrivateCertPath(wxPayProperties.getCertPath());wxPayConfig.setNotifyUrl(WX_NOTIFY_URL);logger.info("微信支付参数wxPayConfig-----{}",wxPayConfig);return wxPayConfig;}

3、调用下单接口

	public WxPayUnifiedOrderV3Result.JsapiResult  wxAppletPay(PayRequestDTO  weChatPayRequest) throws Exception {WxPayConfig wxConfig = this.getWxConfig();WxPayServiceImpl wxPayServiceApacheHttp = new WxPayServiceImpl();wxPayServiceApacheHttp.setConfig(wxConfig);WxPayUnifiedOrderV3Request request = new WxPayUnifiedOrderV3Request();WxPayUnifiedOrderV3Request.Amount amount = new WxPayUnifiedOrderV3Request.Amount();amount.setCurrency("CNY").setTotal(weChatPayRequest.getTotalFee().multiply(new BigDecimal(100)).intValue());WxPayUnifiedOrderV3Request.Payer payer = new WxPayUnifiedOrderV3Request.Payer();payer.setOpenid(weChatPayRequest.getOpenId());WxPayUnifiedOrderV3Request.SceneInfo sceneInfo = new WxPayUnifiedOrderV3Request.SceneInfo();sceneInfo.setPayerClientIp("127.0.0.1");request.setAmount(amount).setPayer(payer).setOutTradeNo(weChatPayRequest.getOutTradeNo()).setSceneInfo(sceneInfo).setDescription(weChatPayRequest.getBody());WxPayUnifiedOrderV3Result result = wxPayServiceApacheHttp.unifiedOrderV3(TradeTypeEnum.JSAPI, request);WxPayConfig wxConfig = this.getWxConfig();String privateKeyPath = wxConfig.getPrivateKeyPath();PrivateKey privateKey = CanteenUtils.getPrivateKey(privateKeyPath);WxPayUnifiedOrderV3Result.JsapiResult payInfo = result.getPayInfo(TradeTypeEnum.JSAPI, wxConfig.getAppId(), wxConfig.getMchId(), privateKey);return  payInfo;}

   生成RSA私钥

	public static PrivateKey getPrivateKey(String filename) throws IOException {String content = new String(Files.readAllBytes(Paths.get(filename)), StandardCharsets.UTF_8);try {String privateKey = content.replace("-----BEGIN PRIVATE KEY-----", "").replace("-----END PRIVATE KEY-----", "").replaceAll("\\s+", "");KeyFactory kf = KeyFactory.getInstance("RSA");return kf.generatePrivate(new PKCS8EncodedKeySpec(Base64.getMimeDecoder().decode(privateKey)));} catch (NoSuchAlgorithmException e) {throw new RuntimeException("当前Java环境不支持RSA", e);} catch (InvalidKeySpecException e) {throw new RuntimeException("无效的密钥格式");}}