前提

minio和kkfileview的docker部署方案就不在这边说明了，搜索博客可以得到答案

配置类

yml

yml
kkfileview: http://127.0.0.1:8012/onlinePreview?url=

# Minio配置
minio:
  url: http://8.129.231.12:9000
  accessKey: minioadmin
  secretKey: minioadmin
  bucketName: test

MinioConfig

java
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import io.minio.MinioClient;

/**
 * Minio 配置信息
 *
 * @author haowee
 */
@Configuration
@ConfigurationProperties(prefix = "minio")
public class MinioConfig
{
    /**
     * 服务地址
     */
    private String url;

    /**
     * 用户名
     */
    private String accessKey;

    /**
     * 密码
     */
    private String secretKey;

    /**
     * 存储桶名称
     */
    private String bucketName;

    /**
     * kkfileview预览文件前缀地址
     */

    public String getUrl()
    {
        return url;
    }

    public void setUrl(String url)
    {
        this.url = url;
    }

    public String getAccessKey()
    {
        return accessKey;
    }

    public void setAccessKey(String accessKey)
    {
        this.accessKey = accessKey;
    }

    public String getSecretKey()
    {
        return secretKey;
    }

    public void setSecretKey(String secretKey)
    {
        this.secretKey = secretKey;
    }

    public String getBucketName()
    {
        return bucketName;
    }

    public void setBucketName(String bucketName)
    {
        this.bucketName = bucketName;
    }

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

KkFileViewConfig

java
package com.haowee.file.config;

import com.haowee.common.core.utils.sign.Base64;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConfigurationProperties(prefix = "kkfileview")
public class KkFileViewConfig {
    private String prefix;

    public String getPrefix() {
        return prefix;
    }

    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }

    public String getKkFileViewUrl(String fileUrl){
        String urlBase64= Base64.encode(fileUrl.getBytes());
        return getPrefix()+urlBase64;
    }
}

SysFileController

java
package com.haowee.file.controller;

import com.haowee.common.core.domain.R;
import com.haowee.common.core.utils.StringUtils;
import com.haowee.common.core.utils.file.FileUtils;
import com.haowee.file.service.ISysFileService;
import com.haowee.system.api.domain.SysFile;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;

/**
 * 文件请求处理
 *
 * @author haowee
 */
@RestController
public class SysFileController
{
    private static final Logger log = LoggerFactory.getLogger(SysFileController.class);

    @Autowired
    private ISysFileService sysFileService;

    /**
     * 文件上传请求
     */
    @PostMapping("upload")
    public R<SysFile> upload(MultipartFile file)
    {
        try
        {
            // 上传并返回访问地址
            String url = sysFileService.uploadFile(file);
            SysFile sysFile = new SysFile();
            sysFile.setName(FileUtils.getName(url));
            sysFile.setUrl(url);
            return R.ok(sysFile);
        }
        catch (Exception e)
        {
            log.error("上传文件失败", e);
            return R.fail(e.getMessage());
        }
    }

    /**
     * 下载文件
     *
     * @param fileUrl 文件地址
     *
     */
    @GetMapping("download")
    public void download(String fileUrl, HttpServletResponse response) {
        sysFileService.downloadFile(fileUrl, response);
    }

    /**
     * 下载文件
     *
     * @param fileUrl 文件地址
     *
     */
    @GetMapping("downloadByRes")
    public ResponseEntity<Resource> downloadByRes(String fileUrl) {
       return sysFileService.downloadFile(fileUrl);
    }

    /**
     * 删除文件
     *
     * @param fileUrl 文件地址
     *
     */
    @DeleteMapping("delete")
    public R delete(String fileUrl){
        boolean result= sysFileService.deleteFile(fileUrl);
        if (result){
            return R.ok();
        }else {
            return R.fail();
        }
    }

    /**
     * 获取文件预览地址
     *
     * @param fileUrl 文件地址
     *
     */
    @GetMapping("presignedUrl")
    public R<String> getPresignedUrl(String fileUrl){
        String url=sysFileService.getPresignedUrl(fileUrl);
        if (StringUtils.isNotBlank(url)){
            return R.ok(url);
        }else {
            return R.fail();
        }
    }
}

ISysFileService

java
package com.haowee.file.service;

import org.springframework.core.io.Resource;
import org.springframework.http.ResponseEntity;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;

/**
 * 文件上传接口
 *
 * @author haowee
 */
public interface ISysFileService
{
    /**
     * 文件上传接口
     *
     * @param file 上传的文件
     * @return 访问地址
     * @throws Exception
     */
    public String uploadFile(MultipartFile file) throws Exception;

    /**
     * 下载文件
     *
     * @param fileUrl 文件地址
     * @param
     */

    void downloadFile(String fileUrl,HttpServletResponse response);

    /**
     * 删除文件
     *
     * @param fileUrl 文件地址
     */
    boolean deleteFile(String fileUrl);

    /**
     * 获取文件预览url
     *
     * @param fileUrl 文件地址
     * @return
     */
    String getPresignedUrl(String fileUrl);

    ResponseEntity<Resource> downloadFile(String fileUrl);
}

MinioSysFileServiceImpl

java
package com.haowee.file.service;

import com.alibaba.nacos.common.utils.IoUtils;
import com.haowee.common.core.utils.StringUtils;
import com.haowee.file.config.KkFileViewConfig;
import com.haowee.file.config.MinioConfig;
import com.haowee.file.utils.FileUploadUtils;
import io.minio.*;
import io.minio.http.Method;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.InputStreamResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.TimeUnit;

/**
 * Minio 文件存储
 *
 * @author haowee
 */

@Service
public class MinioSysFileServiceImpl implements ISysFileService
{
    @Autowired
    private MinioConfig minioConfig;

    @Autowired
    private MinioClient client;

    @Autowired
    private KkFileViewConfig kkFileViewConfig;

    private static final Logger log = LoggerFactory.getLogger(MinioSysFileServiceImpl.class);

    /**
     * Minio文件上传接口
     *
     * @param file 上传的文件
     * @return 访问地址
     * @throws Exception
     */
    @Override
    public String uploadFile(MultipartFile file) throws Exception
    {
        String fileName = FileUploadUtils.extractFilename(file);
        InputStream inputStream = file.getInputStream();
        PutObjectArgs args = PutObjectArgs.builder()
                .bucket(minioConfig.getBucketName())
                .object(fileName)
                .stream(inputStream, file.getSize(), -1)
                .contentType(file.getContentType())
                .build();
        client.putObject(args);
        IoUtils.closeQuietly(inputStream);
        return minioConfig.getUrl() + "/" + minioConfig.getBucketName() + "/" + fileName;
    }

    @Override
    public void downloadFile(String fileUrl,HttpServletResponse response) {
        String fileDir = getFileDir(fileUrl);
        if (StringUtils.isBlank(fileDir)) {
            log.error("文件内容为空！");
            return;
        }
        try {
            // 获取文件流
            InputStream file = client.getObject(GetObjectArgs.builder().bucket(minioConfig.getBucketName()).object(fileDir).build());
            response.reset();
            response.setHeader("Content-Disposition", "attachment;filename=" +
                    URLEncoder.encode(fileUrl.substring(fileUrl.lastIndexOf("/") + 1), String.valueOf(StandardCharsets.UTF_8)));
            response.setContentType("application/octet-stream");
            response.setCharacterEncoding("UTF-8");
            // 获取输出流
            ServletOutputStream servletOutputStream = response.getOutputStream();
            int len;
            byte[] buffer = new byte[1024];
            while ((len = file.read(buffer)) > 0) {
                servletOutputStream.write(buffer, 0, len);
            }
            servletOutputStream.flush();
            file.close();
            servletOutputStream.close();
            log.info("文件{}下载成功", fileDir);
        } catch (Exception e) {
            log.error("文件名: " + fileDir + "下载文件时出现异常: " + e);
        }
    }

    @Override
    public ResponseEntity<Resource> downloadFile(String fileUrl) {
        try {
            // 获取文件路径
            String fileDir = getFileDir(fileUrl);
            // 获取文件输入流
            InputStream file = client.getObject(GetObjectArgs.builder().bucket(minioConfig.getBucketName()).object(fileDir).build());
            // 设置响应头
            HttpHeaders headers = new HttpHeaders();
            headers.add("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileUrl.substring(fileUrl.lastIndexOf("/") + 1), StandardCharsets.UTF_8.toString()));
            headers.add("Content-Type", "application/octet-stream");
            // 返回 ResponseEntity
            return ResponseEntity.ok()
                    .headers(headers)
                    .body(new InputStreamResource(file));
        } catch (Exception e) {
            log.error("下载文件时出现异常: " + e.getMessage(), e);
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
        }
    }

    /**
     * 删除文件
     *
     * @param fileUrl 文件路径
     */
    @Override
    public boolean deleteFile(String fileUrl) {
        // 获取桶名
        String bucketName = minioConfig.getBucketName();
        try {
            String fileDir=getFileDir(fileUrl);
            if (StringUtils.isBlank(fileDir)) {
                log.error("删除文件失败，文件名为空！");
                return false;
            }
            // 判断桶是否存在
            boolean isExist = client.bucketExists(BucketExistsArgs.builder().bucket(bucketName).build());
            // 桶存在
            if (isExist) {
                client.removeObject(RemoveObjectArgs.builder().bucket(bucketName).object(fileDir).build());
                return true;
            } else { // 桶不存在
                log.error("删除文件失败，桶{}不存在", bucketName);
                return false;
            }
        } catch (Exception e) {
            log.error("删除文件时出现异常: " + e.getMessage());
            return false;
        }
    }

    /**
     * 获取文件预览url
     *
     * @param fileUrl 文件名
     * @return 文件预览url
     */
    @Override
    public String getPresignedUrl(String fileUrl) {
        // 获取桶名
        String bucketName = minioConfig.getBucketName();
        String presignedUrl = null;
        try {
            String fileDir=getFileDir(fileUrl);
            if (StringUtils.isBlank(fileDir)) {
                log.error("获取文件预览url失败，文件名为空！");
                return presignedUrl;
            }
            // 判断桶是否存在
            boolean isExist = client.bucketExists(BucketExistsArgs.builder().bucket(bucketName).build());
            // 桶存在
            if (isExist) {
                presignedUrl = client.getPresignedObjectUrl(
                        GetPresignedObjectUrlArgs.builder()
                                .method(Method.PUT)
                                .bucket(bucketName)
                                .object(fileDir)
                                .expiry(1, TimeUnit.DAYS) // 一天过期时间
                                .build());
                return presignedUrl;
                //默认的文件预览只支持pdf,如果需要更多格式请用kkFileView
//                return kkFileViewConfig.getKkFileViewUrl(presignedUrl);
            } else {  // 桶不存在
                log.error("获取文件预览url失败，桶{}不存在", bucketName);
            }
        } catch (Exception e) {
            log.error("获取文件预览url时出现异常: " + e.getMessage());
        }
        return presignedUrl;
    }

    /**
     * 这个文件目录是存储桶名称之后的路径内容
     * @param fileUrl
     * @return
     */
    private String getFileDir(String fileUrl){
        String fileDir=fileUrl.split(minioConfig.getBucketName())[1].substring(1);
        return fileDir;
    }
}