上一篇 写给大忙人看的 - 搭建文件服务器 MinIO（一），我们已经成功地搭建了 MinIO 文件服务器，这一篇讲解在 Java 中如何上传文件至 MinIO

一、开发前戏

1、项目中引入 maven 依赖

<!-- minio 相关依赖 -->
<dependency>
    <groupId>io.minio</groupId>
    <artifactId>minio</artifactId>
    <version>3.0.10</version>
</dependency>
<!-- alibaba的fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.51</version>
</dependency>
<!-- thymeleaf模板引擎 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

这里除了 MinIO 的相关依赖，还添加了 fastjson，thymeleaf 的相关依赖，篇幅原因，其余依赖请自行添加

2、添加配置信息

在 application.yml 文件中加入 MinIO 服务器的相关信息

# minio 文件存储配置信息
minio:
  endpoint: http://127.0.0.1:9000
  accesskey: minioadmin
  secretKey: minioadmin

3、创建实体类

package com.zyxx.email.common.minio;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;


@Data
@Component
@ConfigurationProperties(prefix = "minio")
public class MinioProp {
    
    private String endpoint;
    
    private String accesskey;
    
    private String secretKey;
}

这一步，我们将配置文件中 minio 的配置信息通过注解的方式注入到 MinioProp 这个实体中，方便后面我们使用

4、创建核心配置类

package com.zyxx.email.common.minio;

import io.minio.MinioClient;
import io.minio.errors.InvalidEndpointException;
import io.minio.errors.InvalidPortException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
@EnableConfigurationProperties(MinioProp.class)
public class MinioConfig {

    @Autowired
    private MinioProp minioProp;

    
    @Bean
    public MinioClient minioClient() throws InvalidPortException, InvalidEndpointException {
        return new MinioClient(minioProp.getEndpoint(), minioProp.getAccesskey(), minioProp.getSecretKey());
    }
}

通过注入 MinIO 服务器的相关配置信息，得到 MinioClient 对象，我们上传文件依赖此对象

5、上传工具类

package com.zyxx.email.common.minio;

import com.alibaba.fastjson.JSONObject;
import com.zyxx.email.common.redis.RedisUtil;
import com.zyxx.email.utils.DateUtils;
import io.minio.MinioClient;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

@Slf4j
@Component
public class MinioUtils {

    @Autowired
    private MinioClient client;
    @Autowired
    private MinioProp minioProp;

    
    @SneakyThrows
    public void createBucket(String bucketName) {
        if (!client.bucketExists(bucketName)) {
            client.makeBucket(bucketName);
        }
    }

    
    public JSONObject uploadFile(MultipartFile file, String bucketName) throws Exception {
        JSONObject res = new JSONObject();
        res.put("code", 0);
        // 判断上传文件是否为空
        if (null == file || 0 == file.getSize()) {
            res.put("msg", "上传文件不能为空");
            return res;
        }
        // 判断存储桶是否存在
        createBucket(bucketName);
        // 文件名
        String originalFilename = file.getOriginalFilename();
        // 新的文件名 = 存储桶名称_时间戳.后缀名
        String fileName = bucketName + "_" + System.currentTimeMillis() + originalFilename.substring(originalFilename.lastIndexOf("."));
        // 开始上传
        client.putObject(bucketName, fileName, file.getInputStream(), file.getContentType());
        res.put("code", 1);
        res.put("msg", minioProp.getEndpoint() + "/" + bucketName + "/" + fileName);
        return res;
    }
}

二、开发进行中

1、编写 Controller

package com.zyxx.email.controller;

import com.alibaba.fastjson.JSONObject;
import com.zyxx.email.common.minio.MinioUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;

@Controller
public class MinioController {

    @Autowired
    private MinioUtils minioUtils;

    @GetMapping("init")
    public String init() {
        return "file";
    }

    
    @PostMapping("/upload")
    @ResponseBody
    public String upload(@RequestParam(name = "file", required = false) MultipartFile file, HttpServletRequest request) {
        JSONObject res = null;
        try {
            res = minioUtils.uploadFile(file, "product");
        } catch (Exception e) {
            e.printStackTrace();
            res.put("code", 0);
            res.put("msg", "上传失败");
        }
        return res.toJSONString();
    }
}

2、上传页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta charset="UTF-8">
        <title>首页</title>
    </head>
    <body>
        <form accept-charset="UTF-8" th:action="@{upload}" method="post" enctype="multipart/form-data" target="_blank">
            文件:<input type="file" name="file"/>
            <input type="submit" value="上传"/>
        </form>
    </body>
</html>

这里我用的 thymeleaf 模板引擎

三、上传测试

1、访问地址

http://localhost:8080/init

2、启动 MinIO 文件服务器

3、响应信息

{"msg":"http://127.0.0.1:9000/product/product_1589105654237.png","code":1}

http://127.0.0.1:9000/product/product_1589105654237.png 就是我们上传之后得到的文件地址了

4、访问文件

MinIO 形式上传的文件也不支持直接访问，我们如果需要直接访问，还需要做如下操作：

设置 bucket 的 policy 策略：

设置该存储桶下面的文件为 Read and Write，这时我们就可以直接访问了

四、完整工具类代码

package com.zyxx.email.common.minio;

import com.alibaba.fastjson.JSONObject;
import com.zyxx.email.utils.DateUtils;
import io.minio.MinioClient;
import io.minio.ObjectStat;
import io.minio.messages.Bucket;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import java.io.InputStream;
import java.util.*;

@Slf4j
@Component
public class MinioUtils {

    @Autowired
    private MinioClient client;
    @Autowired
    private MinioProp minioProp;

    
    @SneakyThrows
    public void createBucket(String bucketName) {
        if (!client.bucketExists(bucketName)) {
            client.makeBucket(bucketName);
        }
    }

    
    @SneakyThrows
    public List<Bucket> getAllBuckets() {
        return client.listBuckets();
    }

    
    @SneakyThrows
    public Optional<Bucket> getBucket(String bucketName) {
        return client.listBuckets().stream().filter(b -> b.name().equals(bucketName)).findFirst();
    }

    
    @SneakyThrows
    public void removeBucket(String bucketName) {
        client.removeBucket(bucketName);
    }

    
    @SneakyThrows
    public String getObjectURL(String bucketName, String objectName, Integer expires) {
        return client.presignedGetObject(bucketName, objectName, expires);
    }

    
    @SneakyThrows
    public InputStream getObject(String bucketName, String objectName) {
        return client.getObject(bucketName, objectName);
    }

    
    public void putObject(String bucketName, String objectName, InputStream stream) throws Exception {
        client.putObject(bucketName, objectName, stream, stream.available(), "application/octet-stream");
    }

    
    public void putObject(String bucketName, String objectName, InputStream stream, long size, String contextType) throws Exception {
        client.putObject(bucketName, objectName, stream, size, contextType);
    }

    
    public ObjectStat getObjectInfo(String bucketName, String objectName) throws Exception {
        return client.statObject(bucketName, objectName);
    }

    
    public void removeObject(String bucketName, String objectName) throws Exception {
        client.removeObject(bucketName, objectName);
    }

    
    public JSONObject uploadFile(MultipartFile file, String bucketName) throws Exception {
        JSONObject res = new JSONObject();
        res.put("code", 0);
        // 判断上传文件是否为空
        if (null == file || 0 == file.getSize()) {
            res.put("msg", "上传文件不能为空");
            return res;
        }
        // 判断存储桶是否存在
        createBucket(bucketName);
        // 文件名
        String originalFilename = file.getOriginalFilename();
        // 新的文件名
        String fileName = bucketName + "_" + DateUtils.getYyyymmdd() + originalFilename.substring(originalFilename.lastIndexOf("."));
        // 开始上传
        client.putObject(bucketName, fileName, file.getInputStream(), file.getContentType());
        res.put("code", 1);
        res.put("msg", minioProp.getEndpoint() + "/" + bucketName + "/" + fileName);
        return res;
    }
}

文件的下载功能也相当简单，这里就不一一介绍了

Java Client 指南地址如下：

https://docs.min.io/docs/java-client-quickstart-guide.html

如您在阅读中发现不足，欢迎留言！！！