Java如何实现微信支付v3的支付回调

<dependency>
	  <groupId>com.github.wechatpay-apiv3</groupId>
	  <artifactId>wechatpay-java</artifactId>
	  <version>0.2.6</version>
	</dependency>

Config config = new RSAAutoCertificateConfig.Builder()
                .merchantId(wechatConstant.spMchId)
                .privateKeyFromPath(wechatConstant.privateKeyPath)
                .merchantSerialNumber(wechatConstant.merchantSerialNumber)
                .apiV3Key(wechatConstant.apiV3key)
                .build();

// 从请求头中获取信息
	String timestamp                        = request.getHeader("Wechatpay-Timestamp");
	String nonce                            = request.getHeader("Wechatpay-Nonce");
	String signature                        = request.getHeader("Wechatpay-Signature");
	String singType                         = request.getHeader("Wechatpay-Signature-Type");
	String wechatPayCertificateSerialNumber = request.getHeader("Wechatpay-Serial");

// 初始化解析器 NotificationParser
    NotificationParser parser = new NotificationParser((NotificationConfig) config);

import com.wechat.pay.java.service.partnerpayments.jsapi.model
	// 这个Transaction是微信包里面的
	Transaction decryptObject = parser.parse(requestParam, Transaction.class);

{   
    "code": "FAIL",
    "message": "失败"
}