WechatPayClient

Info

WeChat Pay v3 HTTP client with native Java HttpClient and RSA2048 signature support.

Overview

WechatPayClient implements WeChat Pay v3 API communication using Java's built-in HttpClient. It handles request signing with SHA256withRSA, constructs proper WECHATPAY2-SHA256-RSA2048 authorization headers, and provides methods for native order creation, order query, and order close. The private key is lazily loaded and cached.

Methods

Method	Return Type	Description
isAvailable()	boolean	Check if WeChat Pay is properly configured
createNativeOrder(outTradeNo, description, amountFen)	PlaceOrderResult	Create a native QR code payment order
queryOrder(outTradeNo)	QueryResult	Query order status from WeChat Pay
closeOrder(outTradeNo)	void	Close an unpaid order

PlaceOrderResult

Field	Type	Description
prepayId	String	WeChat prepay ID
codeUrl	String	QR code URL for native payment

QueryResult

Field	Type	Description
tradeState	String	Trade state from WeChat
transactionId	String	WeChat transaction ID
successTime	OffsetDateTime	Payment success time

Helper Method	Description
success()	Returns true if SUCCESS
shouldClose()	Returns true if CLOSED, REVOKED, or PAYERROR

API Endpoints

Operation	Method	Path
Create Native Order	POST	/v3/pay/transactions/native
Query Order	GET	/v3/pay/transactions/out-trade-no/{outTradeNo}?mchid={mchId}
Close Order	POST	/v3/pay/transactions/out-trade-no/{outTradeNo}/close

Request Signing

Authorization: WECHATPAY2-SHA256-RSA2048
  mchid="{mchId}",
  nonce_str="{nonce}",
  timestamp="{timestamp}",
  serial_no="{serialNo}",
  signature="{signature}"

Sign message = METHOD\nPATH\nTIMESTAMP\nNONCE\nBODY\n

Warning

HTTP requests use a 10-second timeout. Connection timeout is 8 seconds.