diff --git a/IJPay-Demo-SpringBoot/src/main/java/com/ijpay/demo/controller/wxpay/WxPayV3Controller.java b/IJPay-Demo-SpringBoot/src/main/java/com/ijpay/demo/controller/wxpay/WxPayV3Controller.java
index 1d55219ba079ccdee5da101d5408de1df3f4a5ee..255c74bde828c60a69f0c6e4524dc196cb3f3c70 100644
--- a/IJPay-Demo-SpringBoot/src/main/java/com/ijpay/demo/controller/wxpay/WxPayV3Controller.java
+++ b/IJPay-Demo-SpringBoot/src/main/java/com/ijpay/demo/controller/wxpay/WxPayV3Controller.java
@@ -166,6 +166,7 @@ public class WxPayV3Controller {
 				// 保存证书
 				FileWriter writer = new FileWriter(certPath);
 				writer.write(publicKey);
+                writer.close(); // 关闭 writer
 				// 获取平台证书序列号
 				X509Certificate certificate = PayKit.getCertificate(new ByteArrayInputStream(publicKey.getBytes()));
 				return certificate.getSerialNumber().toString(16).toUpperCase();