From 39fb4e301f7530548ab3c952d2885e7c788c9d38 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Sat, 6 Dec 2025 14:31:44 -0800
Subject: [PATCH 1/8] save...

---
 .../service/resource/DatasetResource.scala    | 24 +++++++++++++
 frontend/src/app/common/type/dataset.ts       |  1 +
 .../user-dataset-file-renderer.component.ts   |  3 ++
 .../user-dataset-version-creator.component.ts |  1 +
 ...er-dataset-version-filetree.component.html | 15 +++++++-
 ...er-dataset-version-filetree.component.scss |  2 +-
 ...user-dataset-version-filetree.component.ts | 19 ++++++++++-
 .../service/user/dataset/dataset.service.ts   | 10 ++++++
 .../src/app/dashboard/type/dashboard-entry.ts |  2 ++
 .../browse-section.component.html             |  2 +-
 .../browse-section.component.ts               |  4 +++
 sql/updates/16.sql                            | 34 +++++++++++++++++++
 12 files changed, 113 insertions(+), 4 deletions(-)
 create mode 100644 sql/updates/16.sql

diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index 2a67440cf0e..b49fa8cc476 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -1372,4 +1372,28 @@ class DatasetResource {
         Right(response)
     }
   }
+
+  @POST
+  @RolesAllowed(Array("REGULAR", "ADMIN"))
+  @Path("/{did}/update/cover")
+  @Consumes(Array(MediaType.TEXT_PLAIN))
+  def updateDatasetCoverImage(
+                               @PathParam("did") did: Integer,
+                               coverImage: String,
+                               @Auth sessionUser: SessionUser
+                             ): Response = {
+    withTransaction(context) { ctx =>
+      val uid = sessionUser.getUid
+      val datasetDao = new DatasetDao(ctx.configuration())
+      val dataset = getDatasetByID(ctx, did)
+
+      if (!userHasWriteAccess(ctx, did, uid)) {
+        throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
+      }
+
+      dataset.setCoverImage(coverImage)
+      datasetDao.update(dataset)
+      Response.ok().build()
+    }
+  }
 }
diff --git a/frontend/src/app/common/type/dataset.ts b/frontend/src/app/common/type/dataset.ts
index 7825ca27976..97ff370302c 100644
--- a/frontend/src/app/common/type/dataset.ts
+++ b/frontend/src/app/common/type/dataset.ts
@@ -38,4 +38,5 @@ export interface Dataset {
   storagePath: string | undefined;
   description: string;
   creationTime: number | undefined;
+  coverImage: string | undefined;
 }
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
index c851a8284ea..576de576dff 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
@@ -131,6 +131,9 @@ export class UserDatasetFileRendererComponent implements OnInit, OnChanges, OnDe
   @Output()
   loadFile = new EventEmitter<{ file: string; prefix: string }>();
 
+  @Output()
+  setCoverImage = new EventEmitter<string>();
+
   constructor(
     private datasetService: DatasetService,
     private sanitizer: DomSanitizer,
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-creator/user-dataset-version-creator.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-creator/user-dataset-version-creator.component.ts
index c1f9cffc352..1d59e851e34 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-creator/user-dataset-version-creator.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-creator/user-dataset-version-creator.component.ts
@@ -174,6 +174,7 @@ export class UserDatasetVersionCreatorComponent implements OnInit {
         ownerUid: undefined,
         storagePath: undefined,
         creationTime: undefined,
+        coverImage: undefined,
       };
       this.datasetService
         .createDataset(ds)
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.html b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.html
index f09cdb37d4f..ee74c294410 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.html
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.html
@@ -41,13 +41,26 @@
           nz-button
           nzType="link"
           *ngIf="isTreeNodeDeletable && !node.data.children"
-          class="delete-button"
+          class="icon-button"
           (click)="onNodeDeleted(node.data)">
           <i
             nz-icon
             nzType="delete"
             nzTheme="outline"></i>
         </button>
+
+        <button
+          nz-button
+          nzType="link"
+          *ngIf="!node.data.children && isImageFile(node.data.name)"
+          class="icon-button"
+          nz-tooltip="Set as cover"
+          (click)="onSetCover(node.data)">
+          <i
+            nz-icon
+            nzType="picture"
+            nzTheme="outline"></i>
+        </button>
       </span>
     </ng-template>
   </tree-root>
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.scss b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.scss
index edfaab61285..54cbcd44af4 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.scss
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.scss
@@ -22,7 +22,7 @@
 }
 
 /* Styles for the delete button */
-.delete-button {
+.icon-button {
   width: 15px;
   margin-left: 5px;
 }
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
index f3e3e67e1af..cc0820ea544 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
@@ -19,7 +19,10 @@
 
 import { UntilDestroy } from "@ngneat/until-destroy";
 import { AfterViewInit, Component, EventEmitter, Input, Output, ViewChild } from "@angular/core";
-import { DatasetFileNode } from "../../../../../../common/type/datasetVersionFileTree";
+import {
+  DatasetFileNode,
+  getRelativePathFromDatasetFileNode,
+} from "../../../../../../common/type/datasetVersionFileTree";
 import { ITreeOptions, TREE_ACTIONS } from "@ali-hm/angular-tree-component";
 
 @UntilDestroy()
@@ -40,6 +43,9 @@ export class UserDatasetVersionFiletreeComponent implements AfterViewInit {
 
   @ViewChild("tree") tree: any;
 
+  @Output()
+  setCoverImage = new EventEmitter<string>();
+
   public fileTreeDisplayOptions: ITreeOptions = {
     displayField: "name",
     hasChildrenField: "children",
@@ -74,4 +80,15 @@ export class UserDatasetVersionFiletreeComponent implements AfterViewInit {
       this.tree.treeModel.expandAll();
     }
   }
+
+  isImageFile(fileName: string): boolean {
+    const imageExts = [".jpg", ".jpeg", ".png", ".gif", ".webp"];
+    return imageExts.some(ext => fileName.toLowerCase().endsWith(ext));
+  }
+
+  onSetCover(nodeData: DatasetFileNode): void {
+    const path = getRelativePathFromDatasetFileNode(nodeData);
+    console.log('Setting cover to:', path);
+    this.setCoverImage.emit(path);
+  }
 }
diff --git a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
index c09125d73b1..d5e458337ac 100644
--- a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
+++ b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
@@ -539,4 +539,14 @@ export class DatasetService {
   public retrieveOwners(): Observable<string[]> {
     return this.http.get<string[]>(`${AppSettings.getApiEndpoint()}/${DATASET_GET_OWNERS_URL}`);
   }
+
+  public updateDatasetCoverImage(did: number, coverImagePath: string): Observable<Response> {
+    return this.http.post<Response>(
+      `${AppSettings.getApiEndpoint()}/${DATASET_BASE_URL}/${did}/update/cover`,
+      coverImagePath,
+      {
+        headers: { "Content-Type": "text/plain" },
+      }
+    );
+  }
 }
diff --git a/frontend/src/app/dashboard/type/dashboard-entry.ts b/frontend/src/app/dashboard/type/dashboard-entry.ts
index e526ea01bae..6dfb46cc1cd 100644
--- a/frontend/src/app/dashboard/type/dashboard-entry.ts
+++ b/frontend/src/app/dashboard/type/dashboard-entry.ts
@@ -48,6 +48,7 @@ export class DashboardEntry {
   likeCount: number;
   isLiked: boolean;
   accessibleUserIds: number[];
+  coverImageUrl?: string;
 
   constructor(public value: DashboardWorkflow | DashboardProject | DashboardFile | DashboardDataset) {
     if (isDashboardWorkflow(value)) {
@@ -122,6 +123,7 @@ export class DashboardEntry {
       this.likeCount = 0;
       this.isLiked = false;
       this.accessibleUserIds = [];
+      this.coverImageUrl = value.dataset.coverImage;
     } else {
       throw new Error("Unexpected type in DashboardEntry.");
     }
diff --git a/frontend/src/app/hub/component/browse-section/browse-section.component.html b/frontend/src/app/hub/component/browse-section/browse-section.component.html
index 3d7080e0eb7..71e308b5f89 100644
--- a/frontend/src/app/hub/component/browse-section/browse-section.component.html
+++ b/frontend/src/app/hub/component/browse-section/browse-section.component.html
@@ -44,7 +44,7 @@ <h1 class="card-title">{{ entity.name }}</h1>
           <img
             alt="example"
             class="card-cover-image"
-            [src]="defaultBackground" />
+            [src]="getCoverImage(entity)" />
           <nz-avatar
             class="entity-avatar"
             [ngStyle]="{ 'background-color': 'grey', 'vertical-align': 'middle' }"
diff --git a/frontend/src/app/hub/component/browse-section/browse-section.component.ts b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
index 4527915f6ce..cfb6ac101e4 100644
--- a/frontend/src/app/hub/component/browse-section/browse-section.component.ts
+++ b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
@@ -89,4 +89,8 @@ export class BrowseSectionComponent implements OnInit, OnChanges {
       throw new Error("Unexpected type in DashboardEntry.");
     }
   }
+
+  getCoverImage(entity: DashboardEntry): string {
+    return entity.coverImageUrl || this.defaultBackground;
+  }
 }
diff --git a/sql/updates/16.sql b/sql/updates/16.sql
new file mode 100644
index 00000000000..f2e0c3e36b4
--- /dev/null
+++ b/sql/updates/16.sql
@@ -0,0 +1,34 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- ============================================
+-- 1. Connect to the texera_db database
+-- ============================================
+\c texera_db
+
+SET search_path TO texera_db;
+
+-- ============================================
+-- 2. Update the table schema
+-- ============================================
+BEGIN;
+
+-- 1. Add new column cover_image to dataset table.
+ALTER TABLE dataset
+    ADD COLUMN cover_image varchar(246);
+
+COMMIT;

From 38f34b87fb4d85efb78da2245b48ff0d12c9481e Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Sat, 6 Dec 2025 22:27:31 -0800
Subject: [PATCH 2/8] update.

---
 .../service/resource/DatasetResource.scala     | 12 +++++-------
 .../dataset-detail.component.html              |  3 ++-
 .../dataset-detail.component.ts                | 18 ++++++++++++++++++
 .../user-dataset-version-filetree.component.ts |  1 -
 .../service/user/dataset/dataset.service.ts    |  8 +-------
 .../browse-section.component.html              |  3 ++-
 .../browse-section/browse-section.component.ts |  6 +++++-
 sql/texera_ddl.sql                             |  1 +
 sql/updates/16.sql                             |  2 +-
 9 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index b49fa8cc476..05aa4178ed7 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -1376,15 +1376,13 @@ class DatasetResource {
   @POST
   @RolesAllowed(Array("REGULAR", "ADMIN"))
   @Path("/{did}/update/cover")
-  @Consumes(Array(MediaType.TEXT_PLAIN))
   def updateDatasetCoverImage(
-                               @PathParam("did") did: Integer,
-                               coverImage: String,
-                               @Auth sessionUser: SessionUser
-                             ): Response = {
+      @PathParam("did") did: Integer,
+      coverImage: String,
+      @Auth sessionUser: SessionUser
+  ): Response = {
     withTransaction(context) { ctx =>
       val uid = sessionUser.getUid
-      val datasetDao = new DatasetDao(ctx.configuration())
       val dataset = getDatasetByID(ctx, did)
 
       if (!userHasWriteAccess(ctx, did, uid)) {
@@ -1392,7 +1390,7 @@ class DatasetResource {
       }
 
       dataset.setCoverImage(coverImage)
-      datasetDao.update(dataset)
+      new DatasetDao(ctx.configuration()).update(dataset)
       Response.ok().build()
     }
   }
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.html b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.html
index d4dddf94f6d..79ced02f864 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.html
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.html
@@ -263,7 +263,8 @@ <h6 style="font-weight: lighter; font-size: 0.9em">Choose a Version:</h6>
             [fileTreeNodes]="fileTreeNodeList"
             [isTreeNodeDeletable]="true"
             (selectedTreeNode)="onVersionFileTreeNodeSelected($event)"
-            (deletedTreeNode)="onPreviouslyUploadedFileDeleted($event)">
+            (deletedTreeNode)="onPreviouslyUploadedFileDeleted($event)"
+            (setCoverImage)="onSetCoverImage($event)">
           </texera-user-dataset-version-filetree>
         </nz-collapse-panel>
       </nz-collapse>
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
index b4d12f5a28e..ebbd3a94a75 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
@@ -657,4 +657,22 @@ export class DatasetDetailComponent implements OnInit {
   changeViewDisplayStyle() {
     this.displayPreciseViewCount = !this.displayPreciseViewCount;
   }
+
+  onSetCoverImage(filePath: string): void {
+    if (!this.did || !this.selectedVersion) {
+      return;
+    }
+
+    this.datasetService
+      .updateDatasetCoverImage(this.did, `${this.selectedVersion.name}/${filePath}`)
+      .pipe(untilDestroyed(this))
+      .subscribe({
+        next: () => {
+          this.notificationService.success("Cover image set successfully");
+        },
+        error: (err: unknown) => {
+          this.notificationService.error("Failed to set cover image");
+        },
+      });
+  }
 }
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
index cc0820ea544..cbf490e0c61 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
@@ -88,7 +88,6 @@ export class UserDatasetVersionFiletreeComponent implements AfterViewInit {
 
   onSetCover(nodeData: DatasetFileNode): void {
     const path = getRelativePathFromDatasetFileNode(nodeData);
-    console.log('Setting cover to:', path);
     this.setCoverImage.emit(path);
   }
 }
diff --git a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
index d5e458337ac..a289c28315f 100644
--- a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
+++ b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
@@ -541,12 +541,6 @@ export class DatasetService {
   }
 
   public updateDatasetCoverImage(did: number, coverImagePath: string): Observable<Response> {
-    return this.http.post<Response>(
-      `${AppSettings.getApiEndpoint()}/${DATASET_BASE_URL}/${did}/update/cover`,
-      coverImagePath,
-      {
-        headers: { "Content-Type": "text/plain" },
-      }
-    );
+    return this.http.post<Response>(`${AppSettings.getApiEndpoint()}/dataset/${did}/update/cover`, coverImagePath);
   }
 }
diff --git a/frontend/src/app/hub/component/browse-section/browse-section.component.html b/frontend/src/app/hub/component/browse-section/browse-section.component.html
index 71e308b5f89..2fd8f37525b 100644
--- a/frontend/src/app/hub/component/browse-section/browse-section.component.html
+++ b/frontend/src/app/hub/component/browse-section/browse-section.component.html
@@ -44,7 +44,8 @@ <h1 class="card-title">{{ entity.name }}</h1>
           <img
             alt="example"
             class="card-cover-image"
-            [src]="getCoverImage(entity)" />
+            [src]="getCoverImage(entity)"
+            (error)="$any($event.target).src = defaultBackground" />
           <nz-avatar
             class="entity-avatar"
             [ngStyle]="{ 'background-color': 'grey', 'vertical-align': 'middle' }"
diff --git a/frontend/src/app/hub/component/browse-section/browse-section.component.ts b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
index cfb6ac101e4..0d7de74f23e 100644
--- a/frontend/src/app/hub/component/browse-section/browse-section.component.ts
+++ b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
@@ -91,6 +91,10 @@ export class BrowseSectionComponent implements OnInit, OnChanges {
   }
 
   getCoverImage(entity: DashboardEntry): string {
-    return entity.coverImageUrl || this.defaultBackground;
+    if (entity.type === "dataset" && entity.coverImageUrl) {
+      const fullPath = `${entity.ownerEmail}/${entity.name}/${entity.coverImageUrl}`;
+      return `/api/dataset/file?path=${encodeURIComponent(fullPath)}`;
+    }
+    return this.defaultBackground;
   }
 }
diff --git a/sql/texera_ddl.sql b/sql/texera_ddl.sql
index 7b0f9b9063d..9d8ac7d879e 100644
--- a/sql/texera_ddl.sql
+++ b/sql/texera_ddl.sql
@@ -248,6 +248,7 @@ CREATE TABLE IF NOT EXISTS dataset
     is_downloadable BOOLEAN NOT NULL DEFAULT TRUE,
     description    VARCHAR(512) NOT NULL,
     creation_time  TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    cover_image    varchar(255),
     FOREIGN KEY (owner_uid) REFERENCES "user"(uid) ON DELETE CASCADE
     );
 
diff --git a/sql/updates/16.sql b/sql/updates/16.sql
index f2e0c3e36b4..33f26ef838f 100644
--- a/sql/updates/16.sql
+++ b/sql/updates/16.sql
@@ -29,6 +29,6 @@ BEGIN;
 
 -- 1. Add new column cover_image to dataset table.
 ALTER TABLE dataset
-    ADD COLUMN cover_image varchar(246);
+    ADD COLUMN IF NOT EXISTS cover_image varchar(255);
 
 COMMIT;

From 725a2d8af07a1c77c722faca6e1bf6f96a3fbb41 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Sat, 6 Dec 2025 22:38:35 -0800
Subject: [PATCH 3/8] update..

---
 .../user-dataset-file-renderer.component.ts                    | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
index 576de576dff..c851a8284ea 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-file-renderer/user-dataset-file-renderer.component.ts
@@ -131,9 +131,6 @@ export class UserDatasetFileRendererComponent implements OnInit, OnChanges, OnDe
   @Output()
   loadFile = new EventEmitter<{ file: string; prefix: string }>();
 
-  @Output()
-  setCoverImage = new EventEmitter<string>();
-
   constructor(
     private datasetService: DatasetService,
     private sanitizer: DomSanitizer,

From 430fa9b69f3fb5e187eaced785f30d96e1908f66 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Sun, 7 Dec 2025 17:04:54 -0800
Subject: [PATCH 4/8] update with cover file size limit.

---
 .../service/resource/DatasetResource.scala    | 20 ++++++++++++++++++-
 .../dataset-detail.component.ts               |  4 ++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index 05aa4178ed7..16fad2fa3cf 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -1384,11 +1384,29 @@ class DatasetResource {
     withTransaction(context) { ctx =>
       val uid = sessionUser.getUid
       val dataset = getDatasetByID(ctx, did)
-
       if (!userHasWriteAccess(ctx, did, uid)) {
         throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
       }
 
+      val document = DocumentFactory
+        .openReadonlyDocument(
+          FileResolver.resolve(s"${getOwner(ctx, did).getEmail}/${dataset.getName}/$coverImage")
+        )
+        .asInstanceOf[OnDataset]
+
+      val file = LakeFSStorageClient.getFileFromRepo(
+        document.getRepositoryName(),
+        document.getVersionHash(),
+        document.getFileRelativePath()
+      )
+      val coverSizeLimit = 10 * 1024 * 1024 // 10 MB
+
+      if (file.length() > coverSizeLimit) {
+        throw new BadRequestException(
+          s"Cover image must be less than ${coverSizeLimit / (1024 * 1024)} MB"
+        )
+      }
+
       dataset.setCoverImage(coverImage)
       new DatasetDao(ctx.configuration()).update(dataset)
       Response.ok().build()
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
index ebbd3a94a75..dc495599af4 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
@@ -670,8 +670,8 @@ export class DatasetDetailComponent implements OnInit {
         next: () => {
           this.notificationService.success("Cover image set successfully");
         },
-        error: (err: unknown) => {
-          this.notificationService.error("Failed to set cover image");
+        error: (err: HttpErrorResponse) => {
+          this.notificationService.error(err.error?.message || "Failed to set cover image");
         },
       });
   }

From c742730eb38b39e6b1b96d9dec0bd5d24286e089 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Sat, 3 Jan 2026 16:38:15 -0800
Subject: [PATCH 5/8] update.

---
 .../user-dataset-version-filetree.component.ts            | 8 ++++----
 sql/updates/{16.sql => 17.sql}                            | 0
 2 files changed, 4 insertions(+), 4 deletions(-)
 rename sql/updates/{16.sql => 17.sql} (100%)

diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
index cbf490e0c61..c9203034740 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/user-dataset-version-filetree/user-dataset-version-filetree.component.ts
@@ -25,6 +25,8 @@ import {
 } from "../../../../../../common/type/datasetVersionFileTree";
 import { ITreeOptions, TREE_ACTIONS } from "@ali-hm/angular-tree-component";
 
+const IMAGE_EXTENSIONS = [".jpg", ".jpeg", ".png", ".gif", ".webp"] as const;
+
 @UntilDestroy()
 @Component({
   selector: "texera-user-dataset-version-filetree",
@@ -82,12 +84,10 @@ export class UserDatasetVersionFiletreeComponent implements AfterViewInit {
   }
 
   isImageFile(fileName: string): boolean {
-    const imageExts = [".jpg", ".jpeg", ".png", ".gif", ".webp"];
-    return imageExts.some(ext => fileName.toLowerCase().endsWith(ext));
+    return IMAGE_EXTENSIONS.some(ext => fileName.toLowerCase().endsWith(ext));
   }
 
   onSetCover(nodeData: DatasetFileNode): void {
-    const path = getRelativePathFromDatasetFileNode(nodeData);
-    this.setCoverImage.emit(path);
+    this.setCoverImage.emit(getRelativePathFromDatasetFileNode(nodeData));
   }
 }
diff --git a/sql/updates/16.sql b/sql/updates/17.sql
similarity index 100%
rename from sql/updates/16.sql
rename to sql/updates/17.sql

From 8d8fd1bc7d720ad3222b168f13cdc963ab05fd78 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Mon, 5 Jan 2026 15:45:43 -0800
Subject: [PATCH 6/8] new endpoint.

---
 .../service/resource/DatasetResource.scala    | 100 ++++++++++++++----
 .../dataset-detail.component.ts               |   8 +-
 .../service/user/dataset/dataset.service.ts   |   6 +-
 .../browse-section.component.ts               |  28 ++++-
 sql/updates/{17.sql => 16.sql}                |   0
 sql/updates/18.sql                            |  30 ++++++
 6 files changed, 141 insertions(+), 31 deletions(-)
 rename sql/updates/{17.sql => 16.sql} (100%)
 create mode 100644 sql/updates/18.sql

diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index 78120b50e7e..9257e9eeec5 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -35,28 +35,17 @@ import org.apache.texera.dao.jooq.generated.tables.Dataset.DATASET
 import org.apache.texera.dao.jooq.generated.tables.DatasetUserAccess.DATASET_USER_ACCESS
 import org.apache.texera.dao.jooq.generated.tables.DatasetVersion.DATASET_VERSION
 import org.apache.texera.dao.jooq.generated.tables.User.USER
-import org.apache.texera.dao.jooq.generated.tables.daos.{
-  DatasetDao,
-  DatasetUserAccessDao,
-  DatasetVersionDao
-}
-import org.apache.texera.dao.jooq.generated.tables.pojos.{
-  Dataset,
-  DatasetUserAccess,
-  DatasetVersion
-}
+import org.apache.texera.dao.jooq.generated.tables.daos.{DatasetDao, DatasetUserAccessDao, DatasetVersionDao}
+import org.apache.texera.dao.jooq.generated.tables.pojos.{Dataset, DatasetUserAccess, DatasetVersion}
 import org.apache.texera.service.`type`.DatasetFileNode
 import org.apache.texera.service.resource.DatasetAccessResource._
 import org.apache.texera.service.resource.DatasetResource.{context, _}
 import org.apache.texera.service.util.S3StorageClient
-import org.apache.texera.service.util.S3StorageClient.{
-  MAXIMUM_NUM_OF_MULTIPART_S3_PARTS,
-  MINIMUM_NUM_OF_MULTIPART_S3_PART
-}
+import org.apache.texera.service.util.S3StorageClient.{MAXIMUM_NUM_OF_MULTIPART_S3_PARTS, MINIMUM_NUM_OF_MULTIPART_S3_PART}
 import org.jooq.{DSLContext, EnumType}
 
 import java.io.{InputStream, OutputStream}
-import java.net.{HttpURLConnection, URL, URLDecoder}
+import java.net.{HttpURLConnection, URI, URL, URLDecoder}
 import java.nio.charset.StandardCharsets
 import java.nio.file.{Files, Paths}
 import java.util
@@ -169,6 +158,8 @@ object DatasetResource {
       fileNodes: List[DatasetFileNode],
       size: Long
   )
+
+  case class CoverImageRequest(coverImage: String)
 }
 
 @Produces(Array(MediaType.APPLICATION_JSON, "image/jpeg", "application/pdf"))
@@ -178,6 +169,9 @@ class DatasetResource {
   private val ERR_DATASET_VERSION_NOT_FOUND_MESSAGE = "The version of the dataset not found"
   private val EXPIRATION_MINUTES = 5
 
+  private val COVER_IMAGE_SIZE_LIMIT_BYTES: Long = 10 * 1024 * 1024 // 10 MB
+  private val ALLOWED_IMAGE_EXTENSIONS: Set[String] = Set(".jpg", ".jpeg", ".png", ".gif", ".webp")
+
   /**
     * Helper function to get the dataset from DB with additional information including user access privilege and owner email
     */
@@ -1327,12 +1321,23 @@ class DatasetResource {
     }
   }
 
+  /**
+    * Updates the cover image for a dataset.
+    *
+    * @param did Dataset ID
+    * @param request Cover image request containing the relative file path
+    * @param sessionUser Authenticated user session
+    * @return Response with updated cover image path
+    *
+    * Expected coverImage format: "version/folder/image.jpg" (relative to dataset root)
+    */
   @POST
   @RolesAllowed(Array("REGULAR", "ADMIN"))
   @Path("/{did}/update/cover")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
   def updateDatasetCoverImage(
       @PathParam("did") did: Integer,
-      coverImage: String,
+      request: CoverImageRequest,
       @Auth sessionUser: SessionUser
   ): Response = {
     withTransaction(context) { ctx =>
@@ -1342,9 +1347,23 @@ class DatasetResource {
         throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
       }
 
+      if (request == null || request.coverImage == null || request.coverImage.trim.isEmpty) {
+        throw new BadRequestException("Cover image path is required")
+      }
+
+      val normalized = Paths.get(request.coverImage).normalize().toString
+      if (normalized.startsWith("..") || normalized.startsWith("/")) {
+        throw new BadRequestException("Invalid file path")
+      }
+
+      if (!ALLOWED_IMAGE_EXTENSIONS.exists(ext => normalized.toLowerCase.endsWith(ext))) {
+        throw new BadRequestException("Invalid file type")
+      }
+
+      val owner = getOwner(ctx, did)
       val document = DocumentFactory
         .openReadonlyDocument(
-          FileResolver.resolve(s"${getOwner(ctx, did).getEmail}/${dataset.getName}/$coverImage")
+          FileResolver.resolve(s"${owner.getEmail}/${dataset.getName}/$normalized")
         )
         .asInstanceOf[OnDataset]
 
@@ -1353,17 +1372,54 @@ class DatasetResource {
         document.getVersionHash(),
         document.getFileRelativePath()
       )
-      val coverSizeLimit = 10 * 1024 * 1024 // 10 MB
 
-      if (file.length() > coverSizeLimit) {
+      if (file.length() > COVER_IMAGE_SIZE_LIMIT_BYTES) {
         throw new BadRequestException(
-          s"Cover image must be less than ${coverSizeLimit / (1024 * 1024)} MB"
+          s"Cover image must be less than ${COVER_IMAGE_SIZE_LIMIT_BYTES / (1024 * 1024)} MB"
         )
       }
 
-      dataset.setCoverImage(coverImage)
+      dataset.setCoverImage(normalized)
       new DatasetDao(ctx.configuration()).update(dataset)
-      Response.ok().build()
+      Response.ok(Map("coverImage" -> normalized)).build()
+    }
+  }
+
+  /**
+    * Get the cover image for a public dataset.
+    * Returns a 307 redirect to the presigned S3 URL.
+    *
+    * @param did Dataset ID
+    * @return 307 Temporary Redirect to cover image
+    */
+  @GET
+  @Path("/{did}/cover")
+  def getDatasetCover(@PathParam("did") did: Integer): Response = {
+    withTransaction(context) { ctx =>
+      val dataset = getDatasetByID(ctx, did)
+
+      if (!dataset.getIsPublic) {
+        throw new ForbiddenException("Access denied")
+      }
+
+      val coverImage = Option(dataset.getCoverImage).getOrElse(
+        throw new NotFoundException("No cover image")
+      )
+
+      val owner = getOwner(ctx, did)
+      val fullPath = s"${owner.getEmail}/${dataset.getName}/$coverImage"
+
+      val document = DocumentFactory
+        .openReadonlyDocument(FileResolver.resolve(fullPath))
+        .asInstanceOf[OnDataset]
+
+      val presignedUrl = LakeFSStorageClient.getFilePresignedUrl(
+        document.getRepositoryName(),
+        document.getVersionHash(),
+        document.getFileRelativePath()
+      )
+
+      Response.temporaryRedirect(new URI(presignedUrl)).build()
     }
   }
 }
diff --git a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
index dc495599af4..993edfafe30 100644
--- a/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
+++ b/frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts
@@ -670,8 +670,12 @@ export class DatasetDetailComponent implements OnInit {
         next: () => {
           this.notificationService.success("Cover image set successfully");
         },
-        error: (err: HttpErrorResponse) => {
-          this.notificationService.error(err.error?.message || "Failed to set cover image");
+        error: (err: unknown) => {
+          this.notificationService.error(
+            err instanceof HttpErrorResponse
+              ? err.error?.message || "Failed to set cover image"
+              : "Failed to set cover image"
+          );
         },
       });
   }
diff --git a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
index a289c28315f..c4e01332d0b 100644
--- a/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
+++ b/frontend/src/app/dashboard/service/user/dataset/dataset.service.ts
@@ -540,7 +540,9 @@ export class DatasetService {
     return this.http.get<string[]>(`${AppSettings.getApiEndpoint()}/${DATASET_GET_OWNERS_URL}`);
   }
 
-  public updateDatasetCoverImage(did: number, coverImagePath: string): Observable<Response> {
-    return this.http.post<Response>(`${AppSettings.getApiEndpoint()}/dataset/${did}/update/cover`, coverImagePath);
+  public updateDatasetCoverImage(did: number, coverImage: string): Observable<Response> {
+    return this.http.post<Response>(`${AppSettings.getApiEndpoint()}/dataset/${did}/update/cover`, {
+      coverImage: coverImage,
+    });
   }
 }
diff --git a/frontend/src/app/hub/component/browse-section/browse-section.component.ts b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
index 0d7de74f23e..4e97ff4af8c 100644
--- a/frontend/src/app/hub/component/browse-section/browse-section.component.ts
+++ b/frontend/src/app/hub/component/browse-section/browse-section.component.ts
@@ -28,6 +28,7 @@ import {
   DASHBOARD_USER_DATASET,
   DASHBOARD_USER_WORKSPACE,
 } from "../../../app-routing.constant";
+import { AppSettings } from "../../../common/app-setting";
 
 @UntilDestroy()
 @Component({
@@ -47,6 +48,8 @@ export class BrowseSectionComponent implements OnInit, OnChanges {
   protected readonly DASHBOARD_USER_DATASET = DASHBOARD_USER_DATASET;
   entityRoutes: { [key: number]: string[] } = {};
 
+  private coverImageUrls = new Map<number, string>();
+
   constructor(
     private workflowPersistService: WorkflowPersistService,
     private datasetService: DatasetService,
@@ -57,12 +60,14 @@ export class BrowseSectionComponent implements OnInit, OnChanges {
     this.entities.forEach(entity => {
       this.initializeEntry(entity);
     });
+    this.loadCoverImages();
   }
 
   ngOnChanges(changes: SimpleChanges): void {
     this.entities.forEach(entity => {
       this.initializeEntry(entity);
     });
+    this.loadCoverImages();
   }
 
   private initializeEntry(entity: DashboardEntry): void {
@@ -90,11 +95,24 @@ export class BrowseSectionComponent implements OnInit, OnChanges {
     }
   }
 
+  private loadCoverImages(): void {
+    if (!this.entities) return;
+
+    this.entities
+      .filter(
+        (entity): entity is DashboardEntry & { id: number } =>
+          entity.type === "dataset" &&
+          entity.coverImageUrl !== undefined &&
+          entity.id !== undefined &&
+          !this.coverImageUrls.has(entity.id)
+      )
+      .forEach(entity => {
+        const coverUrl = `${AppSettings.getApiEndpoint()}/dataset/${entity.id}/cover`;
+        this.coverImageUrls.set(entity.id, coverUrl);
+      });
+  }
+
   getCoverImage(entity: DashboardEntry): string {
-    if (entity.type === "dataset" && entity.coverImageUrl) {
-      const fullPath = `${entity.ownerEmail}/${entity.name}/${entity.coverImageUrl}`;
-      return `/api/dataset/file?path=${encodeURIComponent(fullPath)}`;
-    }
-    return this.defaultBackground;
+    return this.coverImageUrls.get(entity.id!) || this.defaultBackground;
   }
 }
diff --git a/sql/updates/17.sql b/sql/updates/16.sql
similarity index 100%
rename from sql/updates/17.sql
rename to sql/updates/16.sql
diff --git a/sql/updates/18.sql b/sql/updates/18.sql
new file mode 100644
index 00000000000..501bbae8e55
--- /dev/null
+++ b/sql/updates/18.sql
@@ -0,0 +1,30 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+\c texera_db
+
+SET search_path TO texera_db;
+
+BEGIN;
+
+-- 1. Add new column cover_image to dataset table.
+ALTER TABLE dataset
+    ADD COLUMN cover_image varchar(246);
+
+COMMIT;

From bc1da4dd5eadb7f267daeee1eaee7b98157bd18e Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Mon, 5 Jan 2026 15:55:42 -0800
Subject: [PATCH 7/8] update.

---
 .../service/resource/DatasetResource.scala    | 21 ++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index 403d9beb001..960738ee69b 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -35,13 +35,24 @@ import org.apache.texera.dao.jooq.generated.tables.Dataset.DATASET
 import org.apache.texera.dao.jooq.generated.tables.DatasetUserAccess.DATASET_USER_ACCESS
 import org.apache.texera.dao.jooq.generated.tables.DatasetVersion.DATASET_VERSION
 import org.apache.texera.dao.jooq.generated.tables.User.USER
-import org.apache.texera.dao.jooq.generated.tables.daos.{DatasetDao, DatasetUserAccessDao, DatasetVersionDao}
-import org.apache.texera.dao.jooq.generated.tables.pojos.{Dataset, DatasetUserAccess, DatasetVersion}
+import org.apache.texera.dao.jooq.generated.tables.daos.{
+  DatasetDao,
+  DatasetUserAccessDao,
+  DatasetVersionDao
+}
+import org.apache.texera.dao.jooq.generated.tables.pojos.{
+  Dataset,
+  DatasetUserAccess,
+  DatasetVersion
+}
 import org.apache.texera.service.`type`.DatasetFileNode
 import org.apache.texera.service.resource.DatasetAccessResource._
 import org.apache.texera.service.resource.DatasetResource.{context, _}
 import org.apache.texera.service.util.S3StorageClient
-import org.apache.texera.service.util.S3StorageClient.{MAXIMUM_NUM_OF_MULTIPART_S3_PARTS, MINIMUM_NUM_OF_MULTIPART_S3_PART}
+import org.apache.texera.service.util.S3StorageClient.{
+  MAXIMUM_NUM_OF_MULTIPART_S3_PARTS,
+  MINIMUM_NUM_OF_MULTIPART_S3_PART
+}
 import org.jooq.{DSLContext, EnumType}
 import org.jooq.impl.DSL
 import org.jooq.impl.DSL.{inline => inl}
@@ -1736,8 +1747,8 @@ class DatasetResource {
       Response.ok(Map("message" -> "Multipart upload aborted successfully")).build()
     }
   }
-  
-    /**
+
+  /**
     * Updates the cover image for a dataset.
     *
     * @param did Dataset ID

From f88f0947041e71c52f6078b4f533ee771a444404 Mon Sep 17 00:00:00 2001
From: Xuan Gu <162244362+xuang7@users.noreply.github.com>
Date: Tue, 6 Jan 2026 14:24:42 -0800
Subject: [PATCH 8/8] update.

---
 .../storage/util/LakeFSStorageClient.scala    |  19 ++
 .../service/resource/DatasetResource.scala    |  49 +++--
 .../resource/DatasetResourceSpec.scala        | 176 ++++++++++++++++++
 3 files changed, 232 insertions(+), 12 deletions(-)

diff --git a/common/workflow-core/src/main/scala/org/apache/texera/amber/core/storage/util/LakeFSStorageClient.scala b/common/workflow-core/src/main/scala/org/apache/texera/amber/core/storage/util/LakeFSStorageClient.scala
index d01e820259d..09fa6f3eb30 100644
--- a/common/workflow-core/src/main/scala/org/apache/texera/amber/core/storage/util/LakeFSStorageClient.scala
+++ b/common/workflow-core/src/main/scala/org/apache/texera/amber/core/storage/util/LakeFSStorageClient.scala
@@ -402,4 +402,23 @@ object LakeFSStorageClient {
     (bucket, key)
   }
 
+  /**
+    * Get file size.
+    *
+    * @param repoName     Repository name.
+    * @param commitHash   Commit hash of the version.
+    * @param filePath     Path to the file in the repository.
+    * @return File size in bytes
+    */
+  def getFileSize(
+      repoName: String,
+      commitHash: String,
+      filePath: String
+  ): Long = {
+    objectsApi
+      .statObject(repoName, commitHash, filePath)
+      .execute()
+      .getSizeBytes
+      .longValue()
+  }
 }
diff --git a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
index 960738ee69b..59437f23a46 100644
--- a/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
+++ b/file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala
@@ -70,6 +70,7 @@ import org.apache.texera.dao.jooq.generated.tables.DatasetUploadSession.DATASET_
 import org.apache.texera.dao.jooq.generated.tables.DatasetUploadSessionPart.DATASET_UPLOAD_SESSION_PART
 import org.jooq.exception.DataAccessException
 import software.amazon.awssdk.services.s3.model.UploadPartResponse
+import org.apache.commons.io.FilenameUtils
 
 import java.sql.SQLException
 import scala.util.Try
@@ -144,6 +145,25 @@ object DatasetResource {
       .toScala
   }
 
+  /**
+    * Validates a file path using Apache Commons IO.
+    */
+  def validateSafePath(path: String): String = {
+    if (path == null || path.trim.isEmpty) {
+      throw new BadRequestException("Path cannot be empty")
+    }
+
+    val normalized = FilenameUtils.normalize(path, true)
+    if (normalized == null) {
+      throw new BadRequestException("Invalid path")
+    }
+
+    if (FilenameUtils.getPrefixLength(normalized) > 0) {
+      throw new BadRequestException("Absolute paths not allowed")
+    }
+    normalized
+  }
+
   case class DashboardDataset(
       dataset: Dataset,
       ownerEmail: String,
@@ -1774,16 +1794,14 @@ class DatasetResource {
         throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
       }
 
-      if (request == null || request.coverImage == null || request.coverImage.trim.isEmpty) {
+      if (request.coverImage == null || request.coverImage.trim.isEmpty) {
         throw new BadRequestException("Cover image path is required")
       }
 
-      val normalized = Paths.get(request.coverImage).normalize().toString
-      if (normalized.startsWith("..") || normalized.startsWith("/")) {
-        throw new BadRequestException("Invalid file path")
-      }
+      val normalized = DatasetResource.validateSafePath(request.coverImage)
 
-      if (!ALLOWED_IMAGE_EXTENSIONS.exists(ext => normalized.toLowerCase.endsWith(ext))) {
+      val extension = FilenameUtils.getExtension(normalized)
+      if (extension == null || !ALLOWED_IMAGE_EXTENSIONS.contains(s".$extension".toLowerCase)) {
         throw new BadRequestException("Invalid file type")
       }
 
@@ -1794,13 +1812,13 @@ class DatasetResource {
         )
         .asInstanceOf[OnDataset]
 
-      val file = LakeFSStorageClient.getFileFromRepo(
+      val fileSize = LakeFSStorageClient.getFileSize(
         document.getRepositoryName(),
         document.getVersionHash(),
         document.getFileRelativePath()
       )
 
-      if (file.length() > COVER_IMAGE_SIZE_LIMIT_BYTES) {
+      if (fileSize > COVER_IMAGE_SIZE_LIMIT_BYTES) {
         throw new BadRequestException(
           s"Cover image must be less than ${COVER_IMAGE_SIZE_LIMIT_BYTES / (1024 * 1024)} MB"
         )
@@ -1813,7 +1831,7 @@ class DatasetResource {
   }
 
   /**
-    * Get the cover image for a public dataset.
+    * Get the cover image for a dataset.
     * Returns a 307 redirect to the presigned S3 URL.
     *
     * @param did Dataset ID
@@ -1821,12 +1839,19 @@ class DatasetResource {
     */
   @GET
   @Path("/{did}/cover")
-  def getDatasetCover(@PathParam("did") did: Integer): Response = {
+  def getDatasetCover(
+      @PathParam("did") did: Integer,
+      @Auth sessionUser: Optional[SessionUser]
+  ): Response = {
     withTransaction(context) { ctx =>
       val dataset = getDatasetByID(ctx, did)
 
-      if (!dataset.getIsPublic) {
-        throw new ForbiddenException("Access denied")
+      val requesterUid = if (sessionUser.isPresent) Some(sessionUser.get().getUid) else None
+
+      if (requesterUid.isEmpty && !dataset.getIsPublic) {
+        throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
+      } else if (requesterUid.exists(uid => !userHasReadAccess(ctx, did, uid))) {
+        throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
       }
 
       val coverImage = Option(dataset.getCoverImage).getOrElse(
diff --git a/file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala b/file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala
index 3f72c574861..43ddbee1cb6 100644
--- a/file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala
+++ b/file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala
@@ -1328,4 +1328,180 @@ class DatasetResourceSpec
     val part1 = fetchPartRows(uploadId).find(_.getPartNumber == 1).get
     part1.getEtag.trim should not be ""
   }
+
+  // ===========================================================================
+  // Cover Image Tests
+  // ===========================================================================
+
+  "updateDatasetCoverImage" should "reject path traversal attempts" in {
+    val maliciousPaths = Seq(
+      "../../../etc/passwd",
+      "v1/../../secret.txt",
+      "../escape.jpg"
+    )
+
+    maliciousPaths.foreach { path =>
+      val request = DatasetResource.CoverImageRequest(path)
+
+      assertThrows[BadRequestException] {
+        datasetResource.updateDatasetCoverImage(
+          baseDataset.getDid,
+          request,
+          sessionUser
+        )
+      }
+    }
+  }
+
+  it should "reject absolute paths" in {
+    val absolutePaths = Seq(
+      "/etc/passwd",
+      "/var/log/system.log"
+    )
+
+    absolutePaths.foreach { path =>
+      val request = DatasetResource.CoverImageRequest(path)
+
+      assertThrows[BadRequestException] {
+        datasetResource.updateDatasetCoverImage(
+          baseDataset.getDid,
+          request,
+          sessionUser
+        )
+      }
+    }
+  }
+
+  it should "reject invalid file types" in {
+    val invalidPaths = Seq(
+      "v1/script.js",
+      "v1/document.pdf",
+      "v1/data.csv"
+    )
+
+    invalidPaths.foreach { path =>
+      val request = DatasetResource.CoverImageRequest(path)
+
+      assertThrows[BadRequestException] {
+        datasetResource.updateDatasetCoverImage(
+          baseDataset.getDid,
+          request,
+          sessionUser
+        )
+      }
+    }
+  }
+
+  it should "reject empty or null cover image path" in {
+    assertThrows[BadRequestException] {
+      datasetResource.updateDatasetCoverImage(
+        baseDataset.getDid,
+        DatasetResource.CoverImageRequest(""),
+        sessionUser
+      )
+    }
+
+    assertThrows[BadRequestException] {
+      datasetResource.updateDatasetCoverImage(
+        baseDataset.getDid,
+        DatasetResource.CoverImageRequest(null),
+        sessionUser
+      )
+    }
+  }
+
+  it should "reject when user lacks WRITE access" in {
+    val request = DatasetResource.CoverImageRequest("v1/cover.jpg")
+
+    assertThrows[ForbiddenException] {
+      datasetResource.updateDatasetCoverImage(
+        baseDataset.getDid,
+        request,
+        sessionUser2
+      )
+    }
+  }
+
+  "getDatasetCover" should "reject private dataset cover for anonymous users" in {
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setIsPublic(false)
+    dataset.setCoverImage("v1/cover.jpg")
+    datasetDao.update(dataset)
+
+    assertThrows[ForbiddenException] {
+      datasetResource.getDatasetCover(baseDataset.getDid, Optional.empty())
+    }
+  }
+
+  it should "reject private dataset cover for users without access" in {
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setOwnerUid(ownerUser.getUid)
+    dataset.setIsPublic(false)
+    dataset.setCoverImage("v1/cover.jpg")
+    datasetDao.update(dataset)
+
+    assertThrows[ForbiddenException] {
+      datasetResource.getDatasetCover(baseDataset.getDid, Optional.of(sessionUser2))
+    }
+  }
+
+  it should "return 404 when no cover image is set" in {
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setCoverImage(null)
+    dataset.setIsPublic(true)
+    datasetDao.update(dataset)
+
+    assertThrows[NotFoundException] {
+      datasetResource.getDatasetCover(baseDataset.getDid, Optional.of(sessionUser))
+    }
+  }
+
+  "validateSafePath" should "accept valid relative paths" in {
+    DatasetResource.validateSafePath("v1/image.jpg") shouldEqual "v1/image.jpg"
+    DatasetResource.validateSafePath("v1/folder/photo.png") shouldEqual "v1/folder/photo.png"
+  }
+
+  it should "normalize safe internal navigation" in {
+    DatasetResource.validateSafePath("v1/../v2/img.jpg") shouldEqual "v2/img.jpg"
+    DatasetResource.validateSafePath("./v1/image.jpg") shouldEqual "v1/image.jpg"
+    DatasetResource.validateSafePath("v1/./image.jpg") shouldEqual "v1/image.jpg"
+  }
+
+  it should "reject path traversal" in {
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("../escape.txt")
+    }
+
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("../../etc/passwd")
+    }
+
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("v1/../../escape.txt")
+    }
+  }
+
+  it should "reject absolute paths" in {
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("/etc/passwd")
+    }
+
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("C:\\windows\\system32")
+    }
+  }
+
+  it should "reject empty or null paths" in {
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath(null)
+    }
+
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("")
+    }
+
+    assertThrows[BadRequestException] {
+      DatasetResource.validateSafePath("   ")
+    }
+  }
 }