修复：商品描述过长导致支付失败的bug

src/main/java/com/gxwebsoft/shop/service/impl/ShopOrderServiceImpl.java

@@ -141,7 +141,13 @@ import com.gxwebsoft.common.core.service.PaymentCacheService;
       request.setAmount(amount);
       request.setAppid(payment.getAppId());
       request.setMchid(payment.getMchId());
-      request.setDescription(order.getComments());
+      // 微信支付description字段限制127字节，需要截断处理
+      String description = order.getComments();
+      if (description != null) {
+        // 确保字节数不超过127字节
+        description = truncateToByteLimit(description, 127);
+      }
+      request.setDescription(description);
       request.setOutTradeNo(order.getOrderNo());
       request.setAttach(order.getTenantId().toString());
       final Payer payer = new Payer();
@@ -667,4 +673,43 @@ import com.gxwebsoft.common.core.service.PaymentCacheService;
       }
     }
 
+    /**
+     * 截断字符串以确保字节数不超过指定限制
+     * 微信支付description字段限制127字节
+     *
+     * @param text 原始文本
+     * @param maxBytes 最大字节数
+     * @return 截断后的文本
+     */
+    private String truncateToByteLimit(String text, int maxBytes) {
+        if (text == null || text.isEmpty()) {
+            return text;
+        }
+
+        byte[] bytes = text.getBytes(java.nio.charset.StandardCharsets.UTF_8);
+        if (bytes.length <= maxBytes) {
+            return text;
+        }
+
+        // 截断字节数组，但要确保不会截断UTF-8字符的中间
+        int truncateLength = maxBytes;
+        while (truncateLength > 0) {
+            byte[] truncated = new byte[truncateLength];
+            System.arraycopy(bytes, 0, truncated, 0, truncateLength);
+
+            try {
+                String result = new String(truncated, java.nio.charset.StandardCharsets.UTF_8);
+                // 检查是否有无效字符（被截断的UTF-8字符）
+                if (!result.contains("\uFFFD")) {
+                    return result;
+                }
+            } catch (Exception e) {
+                // 继续尝试更短的长度
+            }
+            truncateLength--;
+        }
+
+        return ""; // 如果无法安全截断，返回空字符串
+    }
+
   }