Implementing Online File Preview with SpringBoot, MinIO, and kkFileView

kkFileView Overview

kkFileView is an open‑source universal online preview project built on SpringBoot, currently with over 21k stars on Gitee, easy to deploy and supports almost all common file types.

Installation

MinIO

Download the MinIO Docker image and run it, exposing the console on port 9001 and the service on port 9090.

docker pull minio/minio

docker run -p 9090:9000 -p 9001:9001 --name minio \
 -v /mydata/minio/data:/data \
 -e MINIO_ROOT_USER=minioadmin \
 -e MINIO_ROOT_PASSWORD=minioadmin \
 -d minio/minio server /data --console-address ":9001"

Access the console at http://192.168.3.101:9001 using the default credentials minioadmin:minioadmin .

kkFileView

Pull the kkFileView Docker image and run it on port 8012.

docker pull keking/kkfileview

docker run -p 8012:8012 --name kkfileview -d keking/kkfileview

Open the test page at http://192.168.3.101:8012.

Usage

Create a bucket named preview in MinIO, set its policy to Public , upload files, and access them via http://192.168.3.101:9090/{bucket}/{file} . Example: http://192.168.3.101:9090/preview/avatar.png .

File Preview

Use kkFileView’s online preview endpoint with a Base64‑encoded file URL:

http://192.168.3.101:8012/onlinePreview?url=base64Encode($url)

The tool can preview images, Word, PDF, PPT, Markdown, Excel, and even the contents of zip archives, as shown in the screenshots.

Conclusion

The tutorial demonstrates how to achieve arbitrary file online preview in a SpringBoot project using MinIO and kkFileView without writing additional code.

Project address: https://gitee.com/kekingcn/file-online-preview