上篇文章介绍了，这篇文章我们介绍如何使用Spring Boot将文件上传到分布式文件系统FastDFS中。
这个项目会在上一个项目的基础上进行构建。
1、pom包配置
我们使用Spring Boot最新版本1.5.9、jdk使用1.8、tomcat8.0。
org.csource fastdfs-client-java 1.27-SNAPSHOT
加入了fastdfs-client-java包，用来调用FastDFS相关的API。
2、配置文件
resources目录下添加fdfs_client.conf文件
connect_timeout = 60network_timeout = 60charset = UTF-8http.tracker_http_port = 8080http.anti_steal_token = nohttp.secret_key = 123456tracker_server = 192.168.53.85:22122tracker_server = 192.168.53.86:22122
配置文件设置了连接的超时时间，编码格式以及tracker_server地址等信息
详细内容参考：
3、封装FastDFS上传工具类
封装FastDFSFile，文件基础信息包括文件名、内容、文件类型、作者等。
public class FastDFSFile { private String name; private byte[] content; private String ext; private String md5; private String author; //省略getter、setter 封装FastDFSClient类，包含常用的上传、下载、删除等方法。
首先在类加载的时候读取相应的配置信息，并进行初始化。
static { try { String filePath = new ClassPathResource("fdfs_client.conf").getFile().getAbsolutePath();; ClientGlobal.init(filePath); trackerClient = new TrackerClient(); trackerServer = trackerClient.getConnection(); storageServer = trackerClient.getStoreStorage(trackerServer); } catch (Exception e) { logger.error("FastDFS Client Init Fail!",e); }} 文件上传
public static String[] upload(FastDFSFile file) { logger.info("File Name: " + file.getName() + "File Length:" + file.getContent().length); NameValuePair[] meta_list = new NameValuePair[1]; meta_list[0] = new NameValuePair("author", file.getAuthor()); long startTime = System.currentTimeMillis(); String[] uploadResults = null; try { storageClient = new StorageClient(trackerServer, storageServer); uploadResults = storageClient.upload_file(file.getContent(), file.getExt(), meta_list); } catch (IOException e) { logger.error("IO Exception when uploadind the file:" + file.getName(), e); } catch (Exception e) { logger.error("Non IO Exception when uploadind the file:" + file.getName(), e); } logger.info("upload_file time used:" + (System.currentTimeMillis() - startTime) + " ms"); if (uploadResults == null) { logger.error("upload file fail, error code:" + storageClient.getErrorCode()); } String groupName = uploadResults[0]; String remoteFileName = uploadResults[1]; logger.info("upload file successfully!!!" + "group_name:" + groupName + ", remoteFileName:" + " " + remoteFileName); return uploadResults;} 使用FastDFS提供的客户端storageClient来进行文件上传，最后将上传结果返回。
根据groupName和文件名获取文件信息。
public static FileInfo getFile(String groupName, String remoteFileName) { try { storageClient = new StorageClient(trackerServer, storageServer); return storageClient.get_file_info(groupName, remoteFileName); } catch (IOException e) { logger.error("IO Exception: Get File from Fast DFS failed", e); } catch (Exception e) { logger.error("Non IO Exception: Get File from Fast DFS failed", e); } return null;} 下载文件
public static InputStream downFile(String groupName, String remoteFileName) { try { storageClient = new StorageClient(trackerServer, storageServer); byte[] fileByte = storageClient.download_file(groupName, remoteFileName); InputStream ins = new ByteArrayInputStream(fileByte); return ins; } catch (IOException e) { logger.error("IO Exception: Get File from Fast DFS failed", e); } catch (Exception e) { logger.error("Non IO Exception: Get File from Fast DFS failed", e); } return null;} 删除文件
public static void deleteFile(String groupName, String remoteFileName) throws Exception { storageClient = new StorageClient(trackerServer, storageServer); int i = storageClient.delete_file(groupName, remoteFileName); logger.info("delete file successfully!!!" + i);} 使用FastDFS时，直接调用FastDFSClient对应的方法即可。
4、编写上传控制类
从MultipartFile中读取文件信息，然后使用FastDFSClient将文件上传到FastDFS集群中。
public String saveFile(MultipartFile multipartFile) throws IOException { String[] fileAbsolutePath={}; String fileName=multipartFile.getOriginalFilename(); String ext = fileName.substring(fileName.lastIndexOf(".") + 1); byte[] file_buff = null; InputStream inputStream=multipartFile.getInputStream(); if(inputStream!=null){ int len1 = inputStream.available(); file_buff = new byte[len1]; inputStream.read(file_buff); } inputStream.close(); FastDFSFile file = new FastDFSFile(fileName, file_buff, ext); try { fileAbsolutePath = FastDFSClient.upload(file); //upload to fastdfs } catch (Exception e) { logger.error("upload file Exception!",e); } if (fileAbsolutePath==null) { logger.error("upload file failed,please upload again!"); } String path=FastDFSClient.getTrackerUrl()+fileAbsolutePath[0]+ "/"+fileAbsolutePath[1]; return path;} 请求控制，调用上面方法saveFile()。
@PostMapping("/upload") //new annotation since 4.3public String singleFileUpload(@RequestParam("file") MultipartFile file, RedirectAttributes redirectAttributes) { if (file.isEmpty()) { redirectAttributes.addFlashAttribute("message", "Please select a file to upload"); return "redirect:uploadStatus"; } try { // Get the file and save it somewhere String path=saveFile(file); redirectAttributes.addFlashAttribute("message", "You successfully uploaded '" + file.getOriginalFilename() + "'"); redirectAttributes.addFlashAttribute("path", "file path url '" + path + "'"); } catch (Exception e) { logger.error("upload file failed",e); } return "redirect:/uploadStatus";} 上传成功之后，将文件的路径展示到页面，效果图如下：
在浏览器中访问此Url，可以看到成功通过FastDFS展示：
这样使用Spring Boot 集成FastDFS的案例就完成了。