From 82acda9e2442cd62bb7a142edc888688629abf24 Mon Sep 17 00:00:00 2001
From: ye1023 <12588209+ye1023@user.noreply.gitee.com>
Date: Tue, 21 Jul 2026 10:07:57 +0800
Subject: [PATCH] =?UTF-8?q?yxk-20260721=20bug=E4=BF=AE=E5=A4=8D=EF=BC=8Ckk?=
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---
 .../system/controller/FileController.java     | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/jeecg-module-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/controller/FileController.java b/jeecg-module-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/controller/FileController.java
index 6666b95..6270e92 100644
--- a/jeecg-module-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/controller/FileController.java
+++ b/jeecg-module-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/controller/FileController.java
@@ -58,6 +58,8 @@ public class FileController {
     private BaseCommonService baseCommonService;
     @Value(value = "${jeecg.appName}")
     private String applicationName;
+    @Value(value = "${jeecg.file-preview-download-domain:}")
+    private String filePreviewDownloadDomain;
 
     private static final String FILE_PREVIEW_REDIS_PREFIX = "sys:file:preview:";
     private static final long FILE_PREVIEW_TOKEN_EXPIRE_SECONDS = 600L;
@@ -619,7 +621,22 @@ public class FileController {
 
     private String buildPreviewDownloadUrl(HttpServletRequest request, String token, String fileName) {
         // kkFileView judges the preview handler by file suffix; stream APIs without suffix need fullfilename.
-        return buildRequestBaseUrl(request) + "/sys/file/previewDownload?token=" + token + "&fullfilename=" + encodeUrlParam(fileName);
+        return getPreviewDownloadBaseUrl(request) + "/sys/file/previewDownload?token=" + token + "&fullfilename=" + encodeUrlParam(fileName);
+    }
+
+    private String getPreviewDownloadBaseUrl(HttpServletRequest request) {
+        if (!StringUtils.isEmpty(filePreviewDownloadDomain) && !StringUtils.isEmpty(filePreviewDownloadDomain.trim())) {
+            // kkFileView may run on another host, so its download address must not depend on proxy headers.
+            return trimTrailingSlash(filePreviewDownloadDomain.trim());
+        }
+        return buildRequestBaseUrl(request);
+    }
+
+    private String trimTrailingSlash(String value) {
+        while (value.endsWith("/")) {
+            value = value.substring(0, value.length() - 1);
+        }
+        return value;
     }
 
     private JSONObject parsePreviewInfo(Object cache) {