Getting Started with MinIO: Installation, Features, and Spring Boot Integration for File Upload

MinIO is an open‑source, Golang‑based object storage suite licensed under Apache v2.0, offering high performance (up to 55 Gb/s read and 35 Gb/s write), scalability up to 5 TB per object, S3 compatibility, cloud‑native deployment, erasure‑code protection, and SDKs for Go, Java, and Python.

Typical use cases include private cloud object storage and acting as a gateway for public cloud services such as Amazon S3 or Microsoft Azure.

Installation can be done quickly with Docker:

docker pull minio/minio

docker run -p 9000:9000 -p 9001:9001 --name minio -d --restart=always -e "MINIO_ACCESS_KEY=admin" -e "MINIO_SECRET_KEY=admin" -v /home/data:/data -v /home/config:/root/.minio minio/minio server --console-address ":9000" --address ":9001" /data

The -p option maps port 9000 for the web console and port 9001 for the API; MINIO_ACCESS_KEY and MINIO_SECRET_KEY set the console credentials.

After starting the container, access the console at http://<em>ip</em>:9000/login, create a bucket (e.g., test), and set its policy to public.

Spring Boot Integration :

Add the MinIO Maven dependency:

<dependency>
    <groupId>io.minio</groupId>
    <artifactId>minio</artifactId>
    <version>8.2.1</version>
</dependency>

Configure connection details in application.yml (endpoint, port, accessKey, secretKey, bucket name, size limits, etc.).

Create a REST controller to handle file uploads using the MinIO SDK:

@RequestMapping("/minio")
@RestController
public class MinioController {
    @Autowired
    private MinioService minioService;

    @PostMapping("/upload")
    public String uploadFile(MultipartFile file, String bucketName) {
        String fileType = FileTypeUtils.getFileType(file);
        if (fileType != null) {
            return minioService.putObject(file, bucketName, fileType);
        }
        return "Unsupported file format. Please verify and re‑upload!";
    }
}

Testing the endpoint returns a URL that can be accessed directly; the uploaded file appears in the MinIO UI and can be shared with a 7‑day expiration link.

In summary, MinIO provides a powerful, lightweight, and free object storage solution suitable for small projects, personal image hosting, or as a component in larger cloud‑native architectures.