How to Set Up MinIO with Docker and Integrate It into a Spring Boot Application

MinIO is a high‑performance, S3‑compatible object storage released under the AGPL‑v3 license, suitable for machine‑learning, analytics, and application data workloads.

1. Deploy MinIO with Docker

Linux/macOS:

docker run -p 9000:9000 \
  --name minio1 \
  -v /mnt/data:/data \
  -e "MINIO_ROOT_USER=AKIAIOSFODNN7EXAMPLE" \
  -e "MINIO_ROOT_PASSWORD=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY" \
  minio/minio server /data

Windows:

docker run -p 9000:9000 \
  --name minio1 \
  -v D:\data:/data \
  -e "MINIO_ROOT_USER=AKIAIOSFODNN7EXAMPLE" \
  -e "MINIO_ROOT_PASSWORD=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY" \
  minio/minio server /data

The environment variables MINIO_ROOT_USER and MINIO_ROOT_PASSWORD set the access key and secret key. The commands start a single‑node instance; refer to the official documentation for distributed setups.

After the container starts, the MinIO web console is reachable at http://localhost:9000.

2. Spring Boot Integration

Add the following Maven dependencies:

<!-- Thymeleaf template engine -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<!-- MinIO Java client -->
<dependency>
    <groupId>io.minio</groupId>
    <artifactId>minio</artifactId>
    <version>8.2.1</version>
</dependency>

<!-- Lombok (optional) -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

Configure MinIO properties in application.yml (or application.properties):

spring:
  servlet:
    multipart:
      max-file-size: 10MB
      max-request-size: 10MB
  # MinIO configuration
  minio:
    access-key: AKIAIOSFODNN7EXAMPLE
    secret-key: wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
    url: http://localhost:9000
    bucket-name: wdhcr
  thymeleaf:
    cache: false

Create a configuration class to bind these properties and expose a MinioClient bean:

@Configuration
@ConfigurationProperties(prefix = "spring.minio")
@Data
public class MinioConfiguration {
    private String accessKey;
    private String secretKey;
    private String url;
    private String bucketName;

    @Bean
    public MinioClient minioClient() {
        return MinioClient.builder()
                .endpoint(url)
                .credentials(accessKey, secretKey)
                .build();
    }
}

Implement a component MinioComp that provides helper methods for generating presigned policies, uploading files, and obtaining temporary URLs:

@Component
public class MinioComp {

    @Autowired
    private MinioClient minioClient;

    @Autowired
    private MinioConfiguration configuration;

    /** Get presigned POST policy */
    public Map getPolicy(String fileName, ZonedDateTime time) {
        PostPolicy postPolicy = new PostPolicy(configuration.getBucketName(), time);
        postPolicy.addEqualsCondition("key", fileName);
        try {
            Map<String, String> map = minioClient.getPresignedPostFormData(postPolicy);
            HashMap<String, String> map1 = new HashMap<>();
            map.forEach((k, v) -> map1.put(k.replaceAll("-", ""), v));
            map1.put("host", configuration.getUrl() + "/" + configuration.getBucketName());
            return map1;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /** Get presigned object URL */
    public String getPolicyUrl(String objectName, Method method, int time, TimeUnit timeUnit) {
        try {
            return minioClient.getPresignedObjectUrl(
                GetPresignedObjectUrlArgs.builder()
                    .method(method)
                    .bucket(configuration.getBucketName())
                    .object(objectName)
                    .expiry(time, timeUnit)
                    .build());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /** Upload a file */
    public void upload(MultipartFile file, String fileName) {
        try {
            InputStream inputStream = file.getInputStream();
            minioClient.putObject(PutObjectArgs.builder()
                .bucket(configuration.getBucketName())
                .object(fileName)
                .stream(inputStream, file.getSize(), -1)
                .contentType(file.getContentType())
                .build());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /** Get temporary access URL for a file */
    public String getUrl(String objectName, int time, TimeUnit timeUnit) {
        try {
            return minioClient.getPresignedObjectUrl(
                GetPresignedObjectUrlArgs.builder()
                    .method(Method.GET)
                    .bucket(configuration.getBucketName())
                    .object(objectName)
                    .expiry(time, timeUnit)
                    .build());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

Key points:

Use MultipartFile to receive file streams from the front‑end and upload them to MinIO.

Generate a signed formData policy for direct browser uploads.

Generate a temporary presigned URL for direct uploads via HTTP PUT.

Obtain a temporary download URL (default up to 7 days).

3. Front‑End Vue + Element‑UI Demo

The page demonstrates three upload approaches: traditional server‑side upload, direct form‑data upload using the signed policy, and direct URL upload using a presigned PUT URL. The Vue instance defines methods to request policies, upload files, and retrieve URLs via Axios.

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
    <title>Upload Image</title>
</head>
<body>
<div id="app">
    <el-row :gutter="2">
        <!-- Traditional upload -->
        <el-col :span="8">
            <el-upload class="upload-demo" action="#" drag
                       :http-request="uploadHandle">
                <i class="el-icon-upload"></i>
                <div class="el-upload__text">将文件拖到此处，或<em>点击上传</em></div>
                <div class="el-upload__tip" slot="tip">只能上传 jpg/png，且不超过 500kb</div>
            </el-upload>
            <div v-if="imgUrl"><img :src="imgUrl" style="width:40px;height:40px"></img></div>
        </el-col>
        <!-- Form‑data direct upload -->
        <el-col :span="8">
            <el-upload class="upload-demo" action="#" drag
                       :http-request="httpRequestHandle">
                ...
            </el-upload>
            <div v-if="directUrl"><img :src="directUrl" style="width:40px;height:40px"></img></div>
        </el-col>
        <!-- URL direct upload -->
        <el-col :span="8">
            <el-upload class="upload-demo" action="#" drag
                       :http-request="UrlUploadHandle">
                ...
            </el-upload>
            <div v-if="uploadUrl"><img :src="uploadUrl" style="width:40px;height:40px"></img></div>
        </el-col>
    </el-row>
</div>

<script src="https://unpkg.com/vue/dist/vue.js"></script>
<script src="https://unpkg.com/element-ui/lib/index.js"></script>
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
<script>
new Vue({
    el: '#app',
    data() { return { imgUrl: '', directUrl: '', uploadUrl: '' } },
    methods: {
        uploadHandle({file}) { this.traditionPost(file); },
        traditionPost(file) { /* send file to /upload */ },
        getpolicy(file) { /* request signed policy then upload */ },
        httpRequestHandle({file}) { this.getpolicy(file); },
        getUploadUrl(file) { /* request presigned PUT URL then upload */ },
        UrlUploadHandle({file}) { this.getUploadUrl(file); },
        axiosPost(method, url, data, config) {
            return axios({method, url, data, headers: config})
                .then(resp => resp)
                .catch(err => "exception=" + err);
        }
    }
});
</script>
<style>
.div-center-class { padding:28% 0; text-align:center; background:beige; }
</style>
</body>
</html>

The article concludes with a link to the full source code repository: https://gitee.com/jack_whh/minio-upload .