kkFileView: An Open‑Source Spring Boot Document Online Preview Solution

kkFileView is a mature, open‑source file‑document online preview solution built with Spring Boot, positioned as a free alternative to commercial products such as Yongzhong Office, Office 365, and iDocv.

Project Features

Supports office, PDF, CAD and other office documents.

Supports plain‑text formats including txt, xml, md, java, php, py, js, css, etc.

Supports archive formats such as zip, rar, jar, tar, gzip.

Supports image formats (jpg, jpeg, png, gif, tif, tiff) with flip, zoom and mirror functions.

Developed with Spring Boot, making deployment and setup straightforward.

Provides RESTful APIs, enabling cross‑language and cross‑platform integration (Java, PHP, Python, Go, …).

Abstract preview service interface facilitates secondary development and addition of new file types.

Released under the Apache license, allowing unrestricted use of the source code.

Official Site and Documentation

Website: https://kkfileview.keking.cn

Online Demo

Note: The demo may be temporarily unavailable.

Demo address: https://file.keking.cn

Project Documentation

Detailed wiki: https://gitee.com/kekingcn/file-online-preview/wikis/pages

Chinese README: https://gitee.com/kekingcn/file-online-preview/blob/master/README.md

English README: https://gitee.com/kekingcn/file-online-preview/blob/master/README.en.md

Preview Effects

1. Text Preview

Supports a wide range of text files (e.g., txt, html, xml, json, properties, md, java, py, c, cpp, sql, sh, bat, etc.).

2. Image Preview

Supports jpg, jpeg, png, gif and provides flip, zoom, and mirror functions.

3. Word Document Preview

Supports doc and docx with two modes: image preview (each page rendered as an image) and PDF preview (entire document converted to PDF). Image mode is suitable for large files; PDF mode is faster on intranet.

4. PPT Document Preview

Supports ppt and pptx with the same two rendering modes as Word.

5. PDF Document Preview

Provides both image‑based and PDF‑based preview modes.

6. Excel Document Preview

Supports xls and xlsx files.

7. Archive File Preview

Supports zip, rar, jar, tar, gzip; users can click file names inside the archive to preview them directly.

8. Multimedia File Preview

Supports common audio and video formats such as mp3, wav, mp4, flv.

9. CAD Document Preview

Supports CAD dwg files with image and PDF rendering modes.

Usage

Project Technologies

Spring Boot

Freemarker

Redisson

JodConverter

External Dependencies

Redis (optional)

OpenOffice or LibreOffice (bundled on Windows; auto‑installed on Linux; manual install on macOS)

Step 1: Pull the project source git clone https://github.com/kekingcn/file-online-preview.git

Step 2: Run the ServerMain class; after the service starts, open http://localhost:8012/ to see the UI, confirming successful startup.

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