Explore kkFileView: Open‑Source Spring Boot Document Preview Engine

Project Background

In many development projects there is a need to preview documents online, covering a large variety of file types. This article introduces kkFileView, an open‑source, easy‑to‑use document preview solution built with Spring Boot, supporting mainstream office formats such as DOC, DOCX, Excel, PDF, TXT, ZIP, RAR, images, and more.

Project Features

Supports office files, PDF, CAD and other documents.

Supports plain text files such as TXT, XML, MD, Java, PHP, PY, JS, CSS, etc.

Supports compressed packages like ZIP, RAR, JAR, TAR, GZIP.

Supports image preview (JPG, JPEG, PNG, GIF, TIF, TIFF) with rotation, scaling, and mirroring.

Built with Spring Boot for simple deployment.

Provides REST APIs for cross‑language and cross‑platform integration.

Abstract preview service interface for easy extension.

Preview Demonstrations

1. Text Preview

All types of text documents can be previewed. Default supported types include txt, html, xml, properties, md, java, py, c, cpp, sql, etc., configurable via a settings file.

2. Image Preview

Supports JPG, JPEG, PNG, GIF, etc., with rotation, scaling, and mirroring.

3. Word Preview

Supports DOC and DOCX. Two rendering modes are available: converting each page to an image, or converting the whole document to PDF. Image mode is faster for large files, while PDF mode loads quickly on intranets.

4. PPT Preview

Supports PPT and PPTX with the same two rendering modes as Word.

5. PDF Preview

Supports PDF with both image and PDF rendering modes.

6. Excel Preview

Supports XLS and XLSX.

7. Archive Preview

Supports ZIP, RAR, JAR, TAR, GZIP. Users can click file names inside the archive to preview directly.

8. Multimedia Preview

Supports most video and audio formats; default enabled types include MP3, WAV, MP4, FLV, configurable via settings.

Open‑source repository: https://gitee.com/kekingcn/file-online-preview Official site: http://kkfileview.keking.cn/