一、pom中加入依赖

  <!--fastdfs文件上传-->
    <dependency>
      <groupId>com.github.tobato</groupId>
      <artifactId>fastdfs-client</artifactId>
      <version>1.26.3</version>
    </dependency>
    <dependency>
      <groupId>net.oschina.zcx7878</groupId>
      <artifactId>fastdfs-client-java</artifactId>
      <version>1.27.0.0</version>
    </dependency>

二、编写配置类

1.配置文件

fdfs:
  # 读取时间
  soTimeout: 1501
  # 连接超时时间
  connectTimeout: 601
  # 编码默认UTF-8，charset属性不能自定义
  # charset: UTF-8
  # 缩略图
  thumbImage:
    # 宽
    width: 150
    # 高
    height: 150
  # tracker列表
  trackerList:
    - ${serverIp}:22122
  pool:
    max-total: 50
    max-wait-millis: 500
  web-server-url: ${serverIp}

2.配置类

import com.github.tobato.fastdfs.FdfsClientConfig;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableMBeanExport;
import org.springframework.context.annotation.Import;
import org.springframework.jmx.support.RegistrationPolicy;

@Configuration
@Import(FdfsClientConfig.class)
@EnableMBeanExport(registration = RegistrationPolicy.IGNORE_EXISTING)// 解决jmx重复注册bean的问题
public class FastDFSConfiguration {

}

三、编写工具类

import com.github.tobato.fastdfs.conn.FdfsWebServer;
import com.github.tobato.fastdfs.domain.StorePath;
import com.github.tobato.fastdfs.exception.FdfsUnsupportStorePathException;
import com.github.tobato.fastdfs.proto.storage.DownloadByteArray;
import com.github.tobato.fastdfs.service.FastFileStorageClient;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.charset.Charset;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

/**fastdfs文件上传工具类
 * @Author kexianjun
 * @Data 2019/9/17 11:02
 * @Description
 * @Project parent
 * @Package com.yncjtz.util
 * @Since JDK1.8
 */

@Component
public class FastDFSClient {
  @Autowired
  private FastFileStorageClient storageClient;

  @Autowired
  private FdfsWebServer fdfsWebServer;

  /**
   * 上传文件
   * @param file 文件对象
   * @return 文件访问地址
   * @throws IOException
   */
  public String uploadFile(MultipartFile file) throws IOException {
    StorePath storePath = storageClient.uploadFile(file.getInputStream(),file.getSize(), FilenameUtils.getExtension(file.getOriginalFilename()),null);
    return getResAccessUrl(storePath);
  }

  /**
   * 上传文件
   * @param file 文件对象
   * @return 文件访问地址
   * @throws IOException
   */
  public String uploadFile(File file) throws IOException {
    FileInputStream inputStream = new FileInputStream (file);
    StorePath storePath = storageClient.uploadFile(inputStream,file.length(), FilenameUtils.getExtension(file.getName()),null);
    return getResAccessUrl(storePath);
  }

  /**
   * 将一段字符串生成一个文件上传
   * @param content 文件内容
   * @param fileExtension
   * @return
   */
  public String uploadFile(String content, String fileExtension) {
    byte[] buff = content.getBytes(Charset.forName("UTF-8"));
    ByteArrayInputStream stream = new ByteArrayInputStream(buff);
    StorePath storePath = storageClient.uploadFile(stream,buff.length, fileExtension,null);
    return getResAccessUrl(storePath);
  }

  // 封装图片完整URL地址
  private String getResAccessUrl(StorePath storePath) {
    String fileUrl = fdfsWebServer.getWebServerUrl() + storePath.getFullPath();
    return fileUrl;
  }

  /**
   * 下载文件
   * @param fileUrl 文件url
   * @return
   */
  public byte[]  download(String fileUrl) {
    String group = fileUrl.substring(0, fileUrl.indexOf("/"));
    String path = fileUrl.substring(fileUrl.indexOf("/") + 1);
    byte[] bytes = storageClient.downloadFile(group, path, new DownloadByteArray());
    return bytes;
  }

  /**
   * 删除文件
   * @param fileUrl 文件访问地址
   * @return
   */
  public void deleteFile(String fileUrl) {
    if (StringUtils.isEmpty(fileUrl)) {
      return;
    }
    try {
      StorePath storePath = StorePath.praseFromUrl(fileUrl);
      storageClient.deleteFile(storePath.getGroup(), storePath.getPath());
    } catch (FdfsUnsupportStorePathException e) {
      e.getMessage();
    }
  }

}

文件上传和下载案列

1.文件上传

        /**
     * 文件上传
     * @param file
     * @return
     * @throws Exception
     */
    @RequestMapping("/upload/file")
    @ResponseBody
    public Map<String,Object> upload(@RequestParam("file") MultipartFile file, Model model) throws Exception{
        Map<String,Object> resultMap = new HashMap<>();
        String url = null;
        try {
            url = fdfsClient.uploadFile(file);
            resultMap.put("code", 200);
            resultMap.put("message", "上传成功");
            resultMap.put("url", url);
            System.out.println(url);
        } catch (Exception e) {
            resultMap.put("status", 500);
            resultMap.put("message", "上传异常！");
        }
        return resultMap;
    }   

2.文件下载

/**
     * 文件下载
     * @param fileUrl  url 开头从组名开始
     * @param response
     * @throws Exception
     */
    @RequestMapping(value="/download", method = {RequestMethod.GET})
    public void  download(HttpServletResponse response, HttpServletRequest request) throws Exception{
        String fileUrl = request.getParameter("fileUrl");
        
        byte[] data = fdfsClient.download(fileUrl);
        
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode("test.jpg", "UTF-8"));
        // 写出
        ServletOutputStream outputStream = response.getOutputStream();
        IOUtils.write(data, outputStream);
    }