java微信支付退款以及退款回调

### Java 实现微信支付退款功能及处理退款回调 #### 1. 创建退款订单 为了实现微信支付的退款功能，在Java环境中首先要创建一个用于发起退款请求的方法。此过程涉及构建必要的参数并发送HTTP POST请求到微信服务器。 ```java import com.fasterxml.jackson.databind.ObjectMapper; import okhttp3.OkHttpClient; import okhttp3.Request; import okhttp3.RequestBody; public class WeChatRefundService { private static final OkHttpClient client = new OkHttpClient(); public String createRefundRequest(String refundOrderId, double amount) { try { Map<String, Object> params = new HashMap<>(); params.put("out_trade_no", "your_original_order_id"); params.put("out_refund_no", refundOrderId); params.put("total_fee", (int)(amount * 100)); // Convert to cents params.put("refund_fee", (int)(amount * 100)); ObjectMapper mapper = new ObjectMapper(); RequestBody body = RequestBody.create( MediaType.parse("application/json; charset=utf-8"), mapper.writeValueAsString(params)); Request request = new Request.Builder() .url("https://api.mch.weixin.qq.com/v3/refund/domestic/refunds") .post(body) .build(); Response response = client.newCall(request).execute(); return response.body().string(); } catch (Exception e) { throw new RuntimeException(e.getMessage()); } } } ``` 上述代码展示了如何构造退款请求的数据包并通过`OkHttp`库向微信API提交POST请求来启动退款流程[^2]。 #### 2. 接收退款通知 当微信完成退款操作后会主动推送一条XML格式的消息给商户配置的通知地址。因此，需要设置好接收端点以解析这些消息，并据此更新本地数据库状态或其他业务逻辑。 ```java @RestController @RequestMapping("/wechat") public class RefundNotificationController { @PostMapping(value="/refundNotify", consumes="text/xml;charset=UTF-8") public ResponseEntity<?> handleWechatRefundNotify(@RequestBody String xmlData){ WxPayOrderApi wxPayOrderApi = new WxPayOrderApi(); try{ wxPayOrderApi.refundNotify(xmlData); // Assuming the method processes and returns success message as XML string. String resultXml = "<xml><return_code><![CDATA[SUCCESS]]></return_code></xml>"; return ResponseEntity.ok(resultXml); }catch(Exception ex){ logger.error("Error processing wechat refund notification.", ex); return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null); } } } ``` 这段Spring Boot控制器定义了一个专门用来监听来自微信平台关于退款成功的异步通知接口[^3]。