上篇文章介紹了如何使用Spring Boot上傳檔案，這篇文章我們介紹如何使用Spring Boot將檔案上傳到分散式檔案系統FastDFS中。

這個專案會在上一個專案的基礎上進行構建。

1、pom包配置

我們使用Spring Boot最新版本1.5.9、jdk使用1.8、tomcat8.0。

<dependency>
    <groupId>org.csource</groupId>
    <artifactId>fastdfs-client-java</artifactId>
    <version>1.27-SNAPSHOT</version>
</dependency>
 

加入了fastdfs-client-java包，用來呼叫FastDFS相關的API。

2、配置檔案

resources目錄下新增fdfs_client.conf檔案

connect_timeout = 60
network_timeout = 60
charset = UTF-8
http.tracker_http_port = 8080
http.anti_steal_token = no
http.secret_key = 123456

tracker_server = 192.168.53.85:22122
tracker_server = 192.168.53.86:22122

配置檔案設定了連線的超時時間，編碼格式以及tracker_server地址等資訊

3、封裝FastDFS上傳工具類

封裝FastDFSFile，檔案基礎資訊包括檔名、內容、檔案型別、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

封裝FastDFSClient類，包含常用的上傳、下載、刪除等方法。

首先在類載入的時候讀取相應的配置資訊，並進行初始化。

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);
    }
}
 

檔案上傳

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提供的客戶端storageClient來進行檔案上傳，最後將上傳結果返回。

根據groupName和檔名獲取檔案資訊。

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;
}

下載檔案

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;
}

刪除檔案

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時，直接呼叫FastDFSClient對應的方法即可。

4、編寫上傳控制類

從MultipartFile中讀取檔案資訊，然後使用FastDFSClient將檔案上傳到FastDFS叢集中。

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;
}

請求控制，呼叫上面方法saveFile()。

@PostMapping("/upload") //new annotation since 4.3
public 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";
}

上傳成功之後，將檔案的路徑展示到頁面，效果圖如下：

在瀏覽器中訪問此Url，可以看到成功通過FastDFS展示：

這樣使用Spring Boot 整合FastDFS的案例就完成了。