SSM框架分页展示Hdfs文件列表，返回上一级，进入下一级，上传文件，删除文件，下载文件前后端代码

1. 分页展示Hdfs文件列表前端代码：

<!-- 文件列表展示 -->
<div class="row">
    <div class="col-md-12">
        <table class="table table-striped table-bordered">
            <thead>
                <tr>
                    <th>文件名</th>
                    <th>修改时间</th>
                    <th>文件大小</th>
                    <th>操作</th>
                </tr>
            </thead>
            <tbody>
                <tr v-for="(item, index) in fileList" :key="index">
                    <td>{{item.name}}</td>
                    <td>{{item.time}}</td>
                    <td>{{item.size}}</td>
                    <td>
                        <button class="btn btn-sm btn-info" @click="gotoSubDir(item)">进入</button>
                        <button class="btn btn-sm btn-danger" @click="deleteFile(item)">删除</button>
                    </td>
                </tr>
            </tbody>
        </table>
    </div>
</div>

<!-- 分页 -->
<div class="row">
    <div class="col-md-12">
        <nav aria-label="Page navigation example">
            <ul class="pagination">
                <li class="page-item" :class="{disabled: currentPage === 1}">
                    <a class="page-link" href="#" @click="prevPage()">上一页</a>
                </li>
                <li class="page-item" v-for="page in pages" :key="page" :class="{active: currentPage === page}">
                    <a class="page-link" href="#" @click="gotoPage(page)">{{page}}</a>
                </li>
                <li class="page-item" :class="{disabled: currentPage === pageCount}">
                    <a class="page-link" href="#" @click="nextPage()">下一页</a>
                </li>
            </ul>
        </nav>
    </div>
</div>

2. 分页展示Hdfs文件列表后端代码：

@Controller
@RequestMapping("/hdfs")
public class HdfsController {

    @Autowired
    private HdfsService hdfsService;

    /**
     * 分页展示Hdfs文件列表
     * @param request
     * @param pageNum
     * @param pageSize
     * @return
     */
    @GetMapping("/list")
    @ResponseBody
    public PageInfo<HdfsFile> list(HttpServletRequest request,
                                   @RequestParam(defaultValue = "1") int pageNum,
                                   @RequestParam(defaultValue = "10") int pageSize) {
        String path = request.getParameter("path");
        return hdfsService.list(path, pageNum, pageSize);
    }

    /**
     * 进入子目录
     * @param request
     * @return
     */
    @GetMapping("/subdir")
    @ResponseBody
    public String subdir(HttpServletRequest request) {
        String path = request.getParameter("path");
        hdfsService.setWorkingDirectory(path);
        return "success";
    }

    /**
     * 返回上一级目录
     * @return
     */
    @GetMapping("/parent")
    @ResponseBody
    public String parent() {
        hdfsService.setParentDirectory();
        return "success";
    }

    /**
     * 删除文件
     * @param request
     * @return
     */
    @PostMapping("/delete")
    @ResponseBody
    public String delete(HttpServletRequest request) {
        String path = request.getParameter("path");
        hdfsService.delete(path);
        return "success";
    }

    /**
     * 上传文件
     * @param file
     * @return
     * @throws IOException
     */
    @PostMapping("/upload")
    @ResponseBody
    public String upload(@RequestParam("file") MultipartFile file) throws IOException {
        String filename = file.getOriginalFilename();
        InputStream inputStream = file.getInputStream();
        hdfsService.upload(filename, inputStream);
        return "success";
    }

    /**
     * 下载文件
     * @param request
     * @param response
     * @throws IOException
     */
    @GetMapping("/download")
    public void download(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String path = request.getParameter("path");
        InputStream inputStream = hdfsService.download(path);
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment; filename=" + new File(path).getName());
        IOUtils.copy(inputStream, response.getOutputStream());
        response.flushBuffer();
    }
}

3. 分页展示Hdfs文件列表服务层代码：

@Service
public class HdfsServiceImpl implements HdfsService {

    private FileSystem fileSystem;
    private Path workingDirectory;

    @Override
    public void init() throws IOException {
        Configuration configuration = new Configuration();
        fileSystem = FileSystem.get(URI.create("hdfs://localhost:9000"), configuration, "hadoop");
        setWorkingDirectory("/");
    }

    @Override
    public void setWorkingDirectory(String path) {
        if (path.startsWith("/")) {
            workingDirectory = new Path(path);
        } else {
            workingDirectory = new Path(workingDirectory, path);
        }
    }

    @Override
    public void setParentDirectory() {
        workingDirectory = workingDirectory.getParent();
    }

    @Override
    public PageInfo<HdfsFile> list(String path, int pageNum, int pageSize) {
        boolean isDir = StringUtils.isBlank(path) || path.equals("/");
        if (isDir) {
            path = workingDirectory.toString();
        }
        try {
            FileStatus[] fileStatuses = fileSystem.listStatus(new Path(path));
            List<HdfsFile> fileList = Arrays.stream(fileStatuses)
                    .map(fileStatus -> new HdfsFile(fileStatus.getPath().toString(),
                            fileStatus.getModificationTime(),
                            fileStatus.isDirectory() ? "-" : FormatUtils.formatFileSize(fileStatus.getLen())))
                    .collect(Collectors.toList());
            PageInfo<HdfsFile> pageInfo = new PageInfo<>(pageNum, pageSize, fileList);
            return pageInfo;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public void delete(String path) {
        try {
            fileSystem.delete(new Path(path), true);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void upload(String filename, InputStream inputStream) {
        try {
            Path path = new Path(workingDirectory, filename);
            FSDataOutputStream outputStream = fileSystem.create(path);
            IOUtils.copy(inputStream, outputStream);
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public InputStream download(String path) {
        try {
            return fileSystem.open(new Path(path));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}

4. 分页展示Hdfs文件列表工具类代码：

public class FormatUtils {

    /**
     * 格式化文件大小
     * @param size
     * @return
     */
    public static String formatFileSize(long size) {
        DecimalFormat df = new DecimalFormat("#.00");
        String fileSizeString = "";
        if (size < 1024) {
            fileSizeString = df.format((double) size) + "B";
        } else if (size < 1048576) {
            fileSizeString = df.format((double) size / 1024) + "KB";
        } else if (size < 1073741824) {
            fileSizeString = df.format((double) size / 1048576) + "MB";
        } else {
            fileSizeString = df.format((double) size / 1073741824) + "GB";
        }
        return fileSizeString;
    }
}

5. 分页展示Hdfs文件列表实体类代码：

public class HdfsFile implements Serializable {

    private String name;
    private String time;
    private String size;

    public HdfsFile() {
    }

    public HdfsFile(String name, long time, String size) {
        this.name = name;
        this.time = DateFormatUtils.format(time, "yyyy-MM-dd HH:mm:ss");
        this.size = size;
    }

    // getter/setter 略
}