minio安装部署可以看这篇教程：https://blog.csdn.net/qq_43108153/article/details/134016896

创建桶

将私有设置成公开

导入依赖

<!--  minio  -->
<dependency>
    <groupId>io.minio</groupId>
    <artifactId>minio</artifactId>
    <version>8.0.3</version>
</dependency>

yml中配置minio地址、账号密码、桶名称

minio:
#  endpoint: http://192.168.1.100:9000 #线上地址
  endpoint: http://127.0.0.1:9000 #本地地址
  accessKey: minioadmin
  secretKey: minioadmin
  bucketName: mybucket

我们需要这三个类来处理

MinioClientConfig

package com.ckm.ball.config;

import io.minio.MinioClient;
import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

/**
 * @author ckm
 * @version 1.0
 * @className MinIoClientConfig
 * @description
 * @create 2022/9/28 15:27
 */
@Component
@Data
public class MinioClientConfig {

    @Value("${minio.endpoint}")
    private String endpoint;

    @Value("${minio.secretKey}")
    private String secretKey;

    @Value("${minio.accessKey}")
    private String accessKey;


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

MinioObjectItem

package com.ckm.ball.config;

import lombok.Data;

/**
 * @author ckm
 * @version 1.0
 * @className ObjectItem
 * @description
 * @create 2022/9/28 15:30
 */
@Data
public class MinioObjectItem {

    private String objectName;

    private Long size;
}

MinioUtils

package com.ckm.ball.config;

import com.alipay.service.schema.util.StringUtil;
import io.minio.*;
import io.minio.http.Method;
import io.minio.messages.DeleteError;
import io.minio.messages.DeleteObject;
import io.minio.messages.Item;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.UUID;
import java.util.stream.Collectors;

/**
 * @author ckm
 * @version 1.0
 * @className MinioUtils
 * @description
 * @create 2022/9/28 15:30
 */
@Component
public class MinioUtils {


    @Autowired
    private MinioClient minioClient;

    @Value("${minio.bucketName}")
    private String bucketName;

    /**
     * description: 判断bucket是否存在，不存在则创建
     *
     * @return: void
     */
    public boolean existBucket(String name) {
        boolean exists;
        try {
            exists = minioClient.bucketExists(BucketExistsArgs.builder().bucket(name).build());
            if (!exists) {
                minioClient.makeBucket(MakeBucketArgs.builder().bucket(name).build());
                exists = true;
            }
        } catch (Exception e) {
            e.printStackTrace();
            exists = false;
        }
        return exists;
    }

    /**
     * 创建存储bucket
     *
     * @param bucketName 存储bucket名称
     * @return Boolean
     */
    public Boolean makeBucket(String bucketName) {
        try {
            minioClient.makeBucket(MakeBucketArgs.builder()
                    .bucket(bucketName)
                    .build());
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    /**
     * 删除存储bucket
     *
     * @param bucketName 存储bucket名称
     * @return Boolean
     */
    public Boolean removeBucket(String bucketName) {
        try {
            minioClient.removeBucket(RemoveBucketArgs.builder()
                    .bucket(bucketName)
                    .build());
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    /**
     * description: 上传文件
     *
     * @param file
     * @return: java.lang.String
     */
    public String upload(MultipartFile file, String bucketNameStr) {
        String imageId = UUID.randomUUID().toString();
        String fileName = file.getOriginalFilename();
        String[] split = fileName.split("\\.");
        if (split.length > 1) {
            fileName = split[0] + "-" + imageId + "." + split[1];
        } else {
            fileName = fileName + System.currentTimeMillis();
        }
        InputStream in = null;
        try {
            if (StringUtil.isEmpty(bucketNameStr)) {
                bucketNameStr = bucketName;
            }
            in = file.getInputStream();
            minioClient.putObject(PutObjectArgs.builder()
                    .bucket(bucketNameStr)
                    .object(fileName)
                    .stream(in, in.available(), -1)
                    .contentType(file.getContentType())
                    .build()
            );
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
//        return bucketNameStr + "/" + fileName;
        return fileName;
    }

    /**
     * description: 下载文件
     *
     * @param fileName
     * @return: org.springframework.http.ResponseEntity<byte [ ]>
     */
    public ResponseEntity<byte[]> download(String fileName) {
        ResponseEntity<byte[]> responseEntity = null;
        InputStream in = null;
        ByteArrayOutputStream out = null;
        try {
            in = minioClient.getObject(GetObjectArgs.builder().bucket(bucketName).object(fileName).build());
            out = new ByteArrayOutputStream();
            IOUtils.copy(in, out);
            //封装返回值
            byte[] bytes = out.toByteArray();
            HttpHeaders headers = new HttpHeaders();
            try {
                headers.add("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            headers.setContentLength(bytes.length);
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            headers.setAccessControlExposeHeaders(Arrays.asList("*"));
            responseEntity = new ResponseEntity<byte[]>(bytes, headers, HttpStatus.OK);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (in != null) {
                    try {
                        in.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return responseEntity;
    }

    /**
     * 查看文件对象
     *
     * @param bucketName 存储bucket名称
     * @return 存储bucket内文件对象信息
     */
    public List<MinioObjectItem> listObjects(String bucketName) {
        Iterable<Result<Item>> results = minioClient.listObjects(
                ListObjectsArgs.builder().bucket(bucketName).build());
        List<MinioObjectItem> minioObjectItems = new ArrayList<>();
        try {
            for (Result<Item> result : results) {
                Item item = result.get();
                MinioObjectItem minioObjectItem = new MinioObjectItem();
                minioObjectItem.setObjectName(item.objectName());
                minioObjectItem.setSize(item.size());
                minioObjectItems.add(minioObjectItem);
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return minioObjectItems;
    }

    /**
     * 批量删除文件对象
     *
     * @param bucketName 存储bucket名称
     * @param objects    对象名称集合
     */
    public Iterable<Result<DeleteError>> removeObjects(String bucketName, List<String> objects) {
        List<DeleteObject> dos = objects.stream().map(e -> new DeleteObject(e)).collect(Collectors.toList());
        Iterable<Result<DeleteError>> results = minioClient.removeObjects(RemoveObjectsArgs.builder().bucket(bucketName).objects(dos).build());
        return results;
    }

    /**
     * 根据文件名和桶获取文件路径
     *
     * @param bucketName 存储bucket名称
     */
    public String getFileUrl(String bucketName, String objectFile) {
        try {
            if(StringUtil.isEmpty(bucketName)){
                bucketName = this.bucketName;
            }
            return minioClient.getPresignedObjectUrl(GetPresignedObjectUrlArgs.builder()
                    .method(Method.GET)
                    .bucket(bucketName)
                    .object(objectFile)
                    .build()
            );
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

}

业务中测试上传图片

Base64ToMultipartFile转换工具类

package com.ckm.ball.utils;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.MultipartFile;

import java.util.Base64;

@Configuration
public class Base64ToMultipartFile {

    public MultipartFile base64ToMultipartFile (String s) {
        MultipartFile image = null;
        StringBuilder base64 = new StringBuilder("");
        if (s != null && !"".equals(s)) {
            base64.append(s);
            String[] baseStrs = base64.toString().split(",");

            byte[] b = new byte[0];
            b =  Base64.getDecoder().decode(baseStrs[1]);
            for (int j = 0; j < b.length; ++j) {
                if (b[j] < 0) {
                    b[j] += 256;
                }
            }
            image = new BASE64DecodedMultipartFile(b, baseStrs[0]);
        }
        return image;
    }
}

上传成功