SpringBoot整合FastDFS实现文件的上传与下载（详解+扩展）

痛定思痛。 2022-11-30 12:50 1092阅读 0赞

**前言：FastDFS是什么呢？**

**FastDFS是一个开源的轻量级分布式文件系统，它对文件进行管理，功能包括：文件存储、文件同步、文件访问（文件上传、文件下载）等，解决了大容量存储和负载均衡的问题。特别适合以文件为载体的在线服务，如相册网站、视频网站等等。**

**FastDFS为互联网量身定制，充分考虑了冗余备份、负载均衡、线性扩容等机制，并注重高可用、高性能等指标，使用FastDFS很容易搭建一套高性能的文件服务器集群提供文件上传、下载等服务。**

--------------------

### 文章目录 ###

*   *  一。基础配置
     *  二。文件上传
     *  三。文件下载
     *  四。扩展

--------------------

## 一。基础配置 ##

**1.在`pom.xml`文件中导入依赖：**

<dependency>
          <groupId>org.csource</groupId>
          <artifactId>fastdfs-client-java</artifactId>
          <version>1.29-SNAPSHOT</version>
      </dependency>

**注意：该依赖在maven中心仓库中并不存在，需要手动打包并添加到类库中，具体操作方法参照我的另外一篇博客：[解决Dependency ‘org.csource:fastdfs-client-java:1.29-SNAPSHOT‘ not found（解决maven仓库中找不到依赖）的问题][Dependency _org.csource_fastdfs-client-java_1.29-SNAPSHOT_ not found_maven]**

**2.FastDFS配置文件`fdfs_client.conf`，其中主要是对连接FastDFS进行一些配置：**

#连接超时时间
    connect_timeout = 60
    #网络超时时间
    network_timeout = 60
    #字符编码
    charset = UTF-8
    #端口
    http.tracker_http_port = 7099
    http.anti_steal_token = no
    #ip地址
    tracker_server = 192.168.23.222:22122

**3.连接FastDFS工具类FastDFSClient ，其中包含了读取FastDFS的配置文件，文件上传与下载等方法：**

import org.csource.common.MyException;
    import org.csource.common.NameValuePair;
    import org.csource.fastdfs.*;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.stereotype.Component;
    import java.io.IOException;
    
    public class FastDFSClient { 
    
    
    /** * it is to define an logger to record the operation's log */
    
        private static Logger logger = LoggerFactory.getLogger(FastDFSClient.class);
    
        static { 
            try { 
    // 线上
    // String filePath = "/home/data/config/fdfs_client.conf";
    // 线下
                String filePath = "D:\\data\\config\\fdfs_client.conf";
                ClientGlobal.init(filePath);
    // String filePath = new ClassPathResource("fdfs_client.pr operties").getFile().getAbsolutePath();
    // ClientGlobal.initByProperties(filePath);
            } catch (IOException e) { 
                logger.error("Get FastDFS config file fail!",e);
            } catch (MyException e) { 
                logger.error("FastDF init fail!",e);
            }
        }
    
        /** * 根据文件名，文件类型以及字节流数组上传文件 * @param fileName * @param fileExt * @param fileBuff * @return */
        public static String[] upload(String fileName,String fileExt,byte[] fileBuff) { 
            logger.info("File Name : " + fileName + ",File Length : " + fileBuff.length);
            NameValuePair[] meta_list = new NameValuePair[1];
            meta_list[0] = new NameValuePair("author","root");
    
            long startTime = System.currentTimeMillis();
            String[] uploadResults = null;
            StorageClient storageClient = null;
    
            try { 
                storageClient = getTrackerClient();
                uploadResults = storageClient.upload_file(fileBuff,fileExt,meta_list);
            } catch (IOException e) { 
                logger.error("IO Exception when uploading the file : " + fileName,e);
            } catch (MyException e) { 
                logger.error("Non IO Exception when uploading the file : " + fileName,e);
            }
            logger.info("upload_file time used : " + (System.currentTimeMillis() - startTime) + "ms");
    
            if (uploadResults == null && storageClient != null) { 
                logger.error("upload file fail, error code : " + storageClient.getErrorCode());
            } else { 
                String groupName = uploadResults[0];
                String remoteFileName = uploadResults[1];
                logger.info("upload file successfully! " + "group_name : " + groupName + ", remoteFileName : " + remoteFileName );
            }
            return uploadResults;
        }
    
    
    /** * @description this function is to download file from FastDFS and return the byte stream * @param groupName * @param remoteName * @return */
    
        public static byte[] downloadFile(String groupName, String remoteName) { 
            byte[] fileByte = null;
            try { 
                StorageClient storageClient = getTrackerClient();
                System.out.println("group name:"+groupName + ", remote name:" + remoteName);
                fileByte = storageClient.download_file(groupName,remoteName);
            } catch (IOException e) { 
                logger.error("IO Exception: Get file from FastDFS Server failed!",e);
            } catch (MyException e) { 
                logger.error("Non IO Exception: Get file from FastDFS Server failed!",e);
            }
            return fileByte;
        }
    
    
    /** * @description this function is to delete appointed file that stored at FastDFS * @param groupName * @param remoteName * @return */
    
        public static Integer deleteFile(String groupName,String remoteName) { 
            Integer deleteFileNums = null;
            try { 
                StorageClient storageClient = getTrackerClient();
                deleteFileNums = storageClient.delete_file(groupName,remoteName);
            } catch (IOException e) { 
                logger.error("IO Exception: Delete file failed!",e);
            } catch (MyException e) { 
                logger.error("Non IO Exception: Delete file failed",e);
            }
            return deleteFileNums;
        }
    
    
    /** * @description this function is to get appointed file's info from FastDFS * @param groupName * @param remoteName * @return */
    
        public static FileInfo getFileInfo(String groupName, String remoteName) { 
            try { 
                StorageClient storageClient = getTrackerClient();
                return storageClient.get_file_info(groupName,remoteName);
            } catch (IOException e) { 
                logger.error("IO Exception: Get FileInfo from FastDFS failed!",e);
            } catch (MyException e) { 
                logger.error("Non IO Exception: Get FileInfo from FastDFS failed!",e);
            }
            return null;
        }
    
    
    /** * @param groupName * @return * @throws IOException */
    
        public static StorageServer[] getStoreStorages(String groupName) throws IOException, MyException { 
            TrackerClient trackerClient = new TrackerClient();
            TrackerServer trackerServer = trackerClient.getConnection();
            return trackerClient.getStoreStorages(trackerServer,groupName);
        }
    
    
    /** * @param groupName * @param remoteFileName * @return * @throws IOException */
    
        public static ServerInfo[] getFetchStorages(String groupName,String remoteFileName) throws IOException, MyException { 
            TrackerClient trackerClient = new TrackerClient();
            TrackerServer trackerServer = trackerClient.getConnection();
            return trackerClient.getFetchStorages(trackerServer,groupName,remoteFileName);
        }
    
        public static String getFilePath(String groupName, String remoteFileName) throws IOException { 
    // 线上
    // String filePath = "http://218.192.110.129:7099/" + groupName + "/" +remoteFileName;
    // 本地
            String filePath = getTrackerUrl() + groupName + "/" +remoteFileName;
            System.out.println("filePath: " + filePath);
            return filePath;
        }
    
    
    /** * @return * @throws IOException */
    
        private static String getTrackerUrl() throws IOException { 
            return "http://" + getTrackerServer().getInetSocketAddress().getHostString() + ":" + ClientGlobal.getG_tracker_http_port() + "/";
        }
    
    
    
    /** * @description this function is to get the FastDFS's storageClient * @return * @throws IOException */
    
        private static StorageClient getTrackerClient() throws IOException { 
            TrackerServer trackerServer = getTrackerServer();
            StorageClient storageClient = new StorageClient(trackerServer,null);
            return storageClient;
        }
    
    
    /** * @description this function is to get the FastDFS's trackerClient * @return * @throws IOException */
    
        private static TrackerServer getTrackerServer() throws IOException { 
            TrackerClient trackerClient = new TrackerClient();
            TrackerServer trackerServer = trackerClient.getConnection();
            return trackerServer;
        }
    }

## 二。文件上传 ##

**1.文件上传的主要实现思路是将上传文件转换成`byte数组`，获取`文件上传名称`以及`文件类型`，调用`StorageClient`类中的`upload_file`方法，该方法执行成功后返回`上传的所属组别`以及`远程文件名称`，再用`/`连接得到访问url，控制器上传接口代码如下：**

/** * 发送个人站内信 * * @param jwt * @param toIds * @param title * @param content * @param multipartFile * @return */
    @ApiOperation(value = "发送个人站内信")
        @PostMapping("/send")
        public HttpRespond send(
                @RequestHeader("Authorization") String jwt,
                @RequestParam(value = "toIds") Integer[] toIds,
                @RequestParam(value = "title") String title,
                @RequestParam(value = "content") String content,
                @RequestParam(value = "multipartFile") MultipartFile multipartFile) { 
    
            // 获取当前登录的用户信息: userId,
            HashMap<String, String> userInfo = JsonInfoUtils.getUserInfo(jwt);
            if (userInfo == null) { 
                return HttpRespond.unauthorized();
            }
            Integer userId = Integer.valueOf(userInfo.get("userId"));
    
            // 接收人不能为空
            if (toIds == null || toIds.length <= 0) { 
                return HttpRespond.badRequest();
            }
    
            // 开启事务管理
            DefaultTransactionDefinition def = new DefaultTransactionDefinition();
            def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
            TransactionStatus status = txManager.getTransaction(def);
            String tip="";
            try { 
                // 1. 插入 "站内信" 数据
                Message message = new Message();
                message.setTitle(title);
                message.setContent(content);
                message.setType(MessageTypeEnum.NORMAL_MAIL.getCode());
                messageService.save(message);
    
                // 2，插入 "站内信用户关联" 数据
                MessageToUser messageToUser = new MessageToUser();
                messageToUser.setMessageId(message.getId());
                messageToUser.setReadStatus(false);
                messageToUser.setSendId(userId);
                for (Integer toId : toIds) { 
                    messageToUser.setRecId(toId);
                    // 插入数据
                    messageToUserService.save(messageToUser);
    
                    // 发送websocket提示
                    messageWsMsgHandler.sendUnreadCount(toId);
                }
    
                //3.上传附件
                tip=saveAttachment(multipartFile,message.getId(),MessageAttachmentTargetTypeEnum.MESSAGE.getCode());
            } catch (Exception e) { 
                txManager.rollback(status);
                log.error("系统内部错误", e);
                return HttpRespond.unknownException();
            }
            txManager.commit(status);
    
            //如果上传附件类型有误
            if(tip.equals("wrongFileType")){ 
                return HttpRespond.wrongFileType();
            }
            //如果上传文件大小超过100M
            if(tip.equals("wrongFileSize")){ 
                return HttpRespond.wrongFileSize();
            }
    
            return HttpRespond.success();
        }
    
    
    
    /** * 上传保存邮件附件 * 默认支持附件上传类型（jpg,png,txt,doc,pdf,zip,rar） * 默认上传文件大小（100m） */
        private String saveAttachment(MultipartFile multipartFile, int targetId,int targetType) { 
            // 附件上传并插入 "附件" 数据
            //获取上传的原始文件全称
            String fileOriName = multipartFile.getOriginalFilename();
            //获取上传的文件名称
            String fileName = fileOriName.substring(0, fileOriName.lastIndexOf("."));
            String type="jpg,png,txt,doc,pdf,zip,rar";
            //获取上传文件的后缀名（文件类型）
            String fileExt = fileOriName.substring(fileOriName.lastIndexOf(".") + 1);
            //上传文件格式不符合
            if(!type.contains(fileExt)){ 
                return "wrongFileType";
            }
    
            long length = multipartFile.getSize();
            //获取上传文件大小
            double fileSize = FileSizeUtil.getFileSize(length, "B");
            //如果上传文件大小大于100m
            if (fileSize/1048576>100){ 
                return "wrongFileSize";
            }
    
            String size = fileSize + "B";
            String[] uploadResults = null;
            byte[] fileBuff = null;
            InputStream inputStream = null;
            try { 
                //接受字符文件输入流
                inputStream = multipartFile.getInputStream();
                if (inputStream != null) { 
                    //获取数据流中含有字节数
                    int len1 = inputStream.available();
                    fileBuff = new byte[len1];
                    //从(来源)输入流中(读取内容)读取的一定数量字节数,并将它们存储到(去处)缓冲区数组fileBuff中
                    inputStream.read(fileBuff);
                }
            } catch (IOException e) { 
                log.error("IO Exception : add file exception!", e);
            } finally { 
                try { 
                    inputStream.close();
                } catch (IOException e) { 
                    log.error("IO Exception : close Input Stream error!", e);
                }
            }
            //上传文件，返回所属组别以及远程文件名称
            uploadResults = FastDFSClient.upload(fileName, fileExt, fileBuff);
            String groupName = uploadResults[0];
            String remoteName = uploadResults[1];
            String url = null;
            try { 
                //得到上传后远程文件的访问路径
                url = FastDFSClient.getFilePath(groupName, remoteName);
            } catch (IOException e) { 
                log.error("IO Exception : close Input Stream error!", e);
            }
    
            //封装数据
            MessageAttachment attachment = new MessageAttachment();
            attachment.setTargetId(targetId);
            attachment.setTargetType(targetType);
            attachment.setOriginalName(fileOriName);
            attachment.setActualName(fileName);
            attachment.setSize(size);
            attachment.setUrl(url);
            attachment.setFileType(fileExt);
    
            attachmentService.save(attachment);
    
            return "success";
        }

**2.返回上传文件大小工具类：**

/** * @Description：返回上传文件大小 * @Author :zks * @Date :9:55 2020/8/20 */
    public class FileSizeUtil { 
    
        /** * length:文件长度（multipartFile.getSize()) * unit限制单位（B,K,M,G） * @param length * @param unit * @return */
        public static Double getFileSize(long length,String unit){ 
            double fileSize = 0;
            if ("B".equals(unit.toUpperCase())) { 
                fileSize = (double) length;
            } else if ("K".equals(unit.toUpperCase())) { 
                fileSize = (double) length / 1024;
            } else if ("M".equals(unit.toUpperCase())) { 
                fileSize = (double) length / 1048576;
            } else if ("G".equals(unit.toUpperCase())) { 
                fileSize = (double) length / 1073741824;
            }
            return fileSize;
        }
    }

**3.使用postman进行测试：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center]

**4.数据库表结构如下：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center 1]

**5.插入的数据如下：**

> 16  
> 19  
> 1  
> 1575635185311.jpg  
> 1575635185311  
> 84924.0B  
> http://192.168.23.222:7099/group1/M00/00/02/wKgX3l9DjXmAUiFeAAFLvP-tZBQ642.jpg  
> jpg  
> 2020-08-24 17:50:49  
> 2020-08-24 17:50:49 0

**6.根据数据库表信息查看上传文件，路径为：`http://192.168.23.222:7099/group1/M00/00/02/wKgX3l9DjXmAUiFeAAFLvP-tZBQ642.jpg`**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center 2]

**注意：该访问地址由`ip`\+`端口`\+`上传组别`\+`fastdfs内部定义上传位置`\+`内部定义上传名称`**

## 三。文件下载 ##

**1.文件下载主要实现思路是从数据库拿到访问该文件的`远程url`，再以`/`将其进行切割，得到该文件所在`组名`以及`文件地址`，调用`StorageClient`类中的`download_file`方法，该方法执行成功返回该文件的`字节数组`。先根据接口传进来的`下载位置参数`，以及数据库表存储的`文件名称`生成新文件，再调用`FileUtils`类中的`writeByteArrayToFile`方法将返回的byte数组写入到新文件中，控制器下载接口代码如下：**

/** * 附件下载 * * @param id * @param location * @return * @throws IOException */
        @ApiOperation(value = "根据附件id下载附件")
        @GetMapping("/download")
        public HttpRespond download(@RequestParam("id") Integer id, @RequestParam("location") String location) throws IOException { 
            //根据id查找附件信息
            MessageAttachment messageAttachment = attachmentService.getById(id);
    
            // http://192.168.23.222:7099/group1/M00/00/02/wKgX3l8-F9KABdUlAAP5BN0hxz4168.pdf
            String s = messageAttachment.getUrl();
            //以“/”切割4次
            String[] ss = s.split("/", 5);
    
            //根据fastdfs上传组别以及资源名称得到下载字节数组 ss[3]:group1 ss[4]:M00/00/02/wKgX3l8-F9KABdUlAAP5BN0hxz4168.pdf
            byte[] bytes = FastDFSClient.downloadFile(ss[3], ss[4]);
            // 给定文件路径和名称,把"\"替换成"/",target为转义字符，注意替换后重新给字符串赋值
            //D:\fastdfsDownload ----->D:/fastdfsDownload
            location = location.replace("\\", "/");
            String pathName = location + "/" + messageAttachment.getOriginalName();
            File file = new File(pathName);
            //将字节流数组写入文件
            FileUtils.writeByteArrayToFile(file, bytes);
    
            return HttpRespond.success(pathName);
        }

**2.使用postman测试该下载接口：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center 3]  
**注意：上面我用红圈标注的传入参数格式你是不是觉得很奇怪？其实那就是一个下载地址，当我们传入参数中带有+，空格，/，?，%，\#，&，=等特殊符号的时候，可能在服务器端无法获得正确的参数值，此时需要对字符进行转译。这里我们对`：`以及`\`进行了转译，对应转译字符分别为`%3A`和`%2F`。**

**3.打开该文件目录，文件已存在：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center 4]

## 四。扩展 ##

**1.可能用到过FastDFS的小伙伴们都想过一个问题，上传文件的文件名能更改吗？更改之后通过更改后的url能对其进行访问吗？现在我们来试一试，首先登陆服务器，找到我们上传的文件：**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDAwOTQ0Nw_size_16_color_FFFFFF_t_70_pic_center 5]

**2.修改文件名为：football.jpg:**

![在这里插入图片描述][2020082510121013.png_pic_center]  
**4.结果当然是访问出错，找不到该文件，因为上传到fastdfs的文件，它会依照其内部的命名逻辑来进行对应的命名，只有经过其内部逻辑进行命名后，fastdfs才能找到该相应的文件，如果将文件名进行修改，则会出现找不到文件的问题。**

[Dependency _org.csource_fastdfs-client-java_1.29-SNAPSHOT_ not found_maven]: https://blog.csdn.net/weixin_44009447/article/details/107743840
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[2020082510121013.png_pic_center]: /images/20221123/6e10d05ebfcb4df483c59eee9db33793.png