SSM框架分页展示Hdfs文件列表上传文件，删除文件，下载文件前后端代码

### 回答1：
前端代码：

// 分页展示Hdfs文件列表
function listFiles(pageNum) {
    $.ajax({
        url: "/hdfs/list",
        type: "GET",
        dataType: "json",
        data: {"pageNum": pageNum},
        success: function (result) {
            var data = result.data;
            var html = "";
            $.each(data.list, function (index, item) {
                var isDir = item.isDir ? "文件夹" : "文件";
                var size = item.isDir ? "-" : (item.size / 1024).toFixed(2) + "KB";
                html += "<tr><td>" + item.pathSuffix + "</td><td>" + isDir + "</td><td>" + size + "</td><td>" +
                    item.owner + "</td><td>" + item.group + "</td><td>" + item.permission + "</td><td>" +
                    item.modificationTime + "</td><td><button class='btn btn-primary' onclick='downloadFile(\"" + item.path + "\")'>下载</button>" +
                    "<button class='btn btn-danger' onclick='deleteFile(\"" + item.path + "\")'>删除</button></td></tr>";
            });
            $("#file_list").html(html);
            $("#page_info").html("第 " + data.pageNum + " 页，共 " + data.pages + " 页，总 " + data.total + " 条记录");
            $("#page_nav").html("<ul class='pagination'><li><a href='#' onclick='listFiles(1)'>首页</a></li>" +
                "<li><a href='#' onclick='listFiles(" + data.prePage + ")'>上一页</a></li>" +
                "<li><a href='#' onclick='listFiles(" + data.nextPage + ")'>下一页</a></li>" +
                "<li><a href='#' onclick='listFiles(" + data.pages + ")'>末页</a></li></ul>");
        }
    });
}

// 上传文件
function uploadFile() {
    var formData = new FormData();
    formData.append("file", $("#file")[0].files[0]);
    $.ajax({
        url: "/hdfs/upload",
        type: "POST",
        data: formData,
        processData: false,
        contentType: false,
        cache: false,
        success: function (result) {
            if (result.code == 200) {
                alert("上传成功");
                listFiles(1);
            } else {
                alert(result.msg);
            }
        }
    });
}

// 删除文件
function deleteFile(path) {
    if (confirm("您确认要删除该文件吗？")) {
        $.ajax({
            url: "/hdfs/delete",
            type: "POST",
            dataType: "json",
            data: {"path": path},
            success: function (result) {
                if (result.code == 200) {
                    alert("删除成功");
                    listFiles(1);
                } else {
                    alert(result.msg);
                }
            }
        });
    }
}

// 下载文件
function downloadFile(path) {
    window.location.href = "/hdfs/download?path=" + path;
}

后端代码：

// 分页展示Hdfs文件列表
@GetMapping("/list")
@ResponseBody
public ResultDTO listFiles(@RequestParam(defaultValue = "1") Integer pageNum) {
    try {
        PageHelper.startPage(pageNum, 10);
        List<FileStatus> fileStatuses = hdfsService.listFiles("/");
        PageInfo<FileStatus> pageInfo = new PageInfo<>(fileStatuses);
        Map<String, Object> data = new HashMap<>();
        data.put("list", fileStatuses);
        data.put("pageNum", pageInfo.getPageNum());
        data.put("pages", pageInfo.getPages());
        data.put("total", pageInfo.getTotal());
        data.put("prePage", pageInfo.getPrePage());
        data.put("nextPage", pageInfo.getNextPage());
        return ResultDTO.success(data);
    } catch (IOException e) {
        return ResultDTO.fail("获取文件列表失败：" + e.getMessage());
    }
}

// 上传文件
@PostMapping("/upload")
@ResponseBody
public ResultDTO uploadFile(@RequestParam("file") MultipartFile file) {
    try {
        if (file.isEmpty()) {
            return ResultDTO.fail("上传文件不能为空");
        }
        String fileName = file.getOriginalFilename();
        String filePath = "/uploads/" + fileName;
        boolean result = hdfsService.uploadFile(file.getInputStream(), filePath);
        if (result) {
            return ResultDTO.success("上传成功");
        } else {
            return ResultDTO.fail("上传失败");
        }
    } catch (IOException e) {
        return ResultDTO.fail("上传失败：" + e.getMessage());
    }
}

// 删除文件
@PostMapping("/delete")
@ResponseBody
public ResultDTO deleteFile(@RequestParam String path) {
    try {
        boolean result = hdfsService.deleteFile(path);
        if (result) {
            return ResultDTO.success("删除成功");
        } else {
            return ResultDTO.fail("删除失败");
        }
    } catch (IOException e) {
        return ResultDTO.fail("删除失败：" + e.getMessage());
    }
}

// 下载文件
@GetMapping("/download")
@ResponseBody
public void downloadFile(@RequestParam String path, HttpServletResponse response) {
    try {
        InputStream inputStream = hdfsService.readFile(path);
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(path.substring(path.lastIndexOf("/") + 1), "UTF-8"));
        IOUtils.copy(inputStream, response.getOutputStream());
        response.flushBuffer();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

### 回答2：
SSM框架是指Spring + SpringMVC + MyBatis的组合，以下是一个用SSM框架实现分页展示HDFS文件列表、上传文件、删除文件、下载文件的前后端代码示例。

后端代码示例（使用Java语言编写）：
1. 文件服务接口（FileService.java）：

public interface FileService {
    List<String> getFileList(int pageNum, int pageSize);
    void uploadFile(MultipartFile file);
    void deleteFile(String filename);
    void downloadFile(String filename, HttpServletResponse response);
}

2. 文件服务实现类（FileServiceImpl.java）：

@Service
public class FileServiceImpl implements FileService {
    private static final String HDFS_PATH = "hdfs://localhost:9000/";

    @Override
    public List<String> getFileList(int pageNum, int pageSize) {
        List<String> fileList = new ArrayList<>();

        try {
            Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(URI.create(HDFS_PATH), conf);

            RemoteIterator<LocatedFileStatus> it = fs.listFiles(new Path(HDFS_PATH), true);

            // 跳过前pageNum*pageSize个文件
            for (int i = 0; i < pageNum * pageSize; i++) {
                if (it.hasNext()) {
                    it.next();
                } else {
                    break;
                }
            }

            // 获取接下来的pageSize个文件路径
            for (int i = 0; i < pageSize; i++) {
                if (it.hasNext()) {
                    fileList.add(it.next().getPath().toString());
                } else {
                    break;
                }
            }

            fs.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return fileList;
    }

    @Override
    public void uploadFile(MultipartFile file) {
        try {
            Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(URI.create(HDFS_PATH), conf);

            fs.copyFromLocalFile(new Path(file.getOriginalFilename()), new Path(HDFS_PATH));

            fs.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void deleteFile(String filename) {
        try {
            Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(URI.create(HDFS_PATH), conf);

            fs.delete(new Path(HDFS_PATH + filename), true);

            fs.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void downloadFile(String filename, HttpServletResponse response) {
        try {
            Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(URI.create(HDFS_PATH), conf);

            response.setHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
            response.setContentType("application/octet-stream");

            IOUtils.copyBytes(fs.open(new Path(HDFS_PATH + filename)), response.getOutputStream(), conf);

            fs.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

3. 控制器类（FileController.java）：

@RestController
@RequestMapping("/file")
public class FileController {
    @Autowired
    private FileService fileService;

    @GetMapping("/list")
    public List<String> getFileList(@RequestParam("pageNum") int pageNum, @RequestParam("pageSize") int pageSize) {
        return fileService.getFileList(pageNum, pageSize);
    }

    @PostMapping("/upload")
    public void uploadFile(@RequestParam("file") MultipartFile file) {
        fileService.uploadFile(file);
    }

    @DeleteMapping("/delete")
    public void deleteFile(@RequestParam("filename") String filename) {
        fileService.deleteFile(filename);
    }

    @GetMapping("/download")
    public void downloadFile(@RequestParam("filename") String filename, HttpServletResponse response) {
        fileService.downloadFile(filename, response);
    }
}

前端代码示例：
页面展示文件列表、上传文件、删除文件使用HTML和JavaScript实现，其中API请求使用jQuery的`ajax`方法。

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <title>HDFS文件管理</title>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
    <h1>HDFS文件管理</h1>
    <h2>文件列表</h2>
    <div id="fileList"></div>
    <h2>上传文件</h2>
    <input type="file" id="fileInput">
    <button type="button" onclick="uploadFile()">上传</button>
    <h2>删除文件</h2>
    <input type="text" id="filenameInput" placeholder="文件名">
    <button type="button" onclick="deleteFile()">删除</button>

    <script>
        // 获取文件列表
        function getFileList(pageNum, pageSize) {
            $.ajax({
                url: "/file/list",
                type: "GET",
                data: {
                    pageNum: pageNum,
                    pageSize: pageSize
                },
                success: function (data) {
                    var fileList = "";
                    for (var i = 0; i < data.length; i++) {
                        fileList += "<p>" + data[i] + "</p>";
                    }
                    $("#fileList").html(fileList);
                },
                error: function () {
                    alert("获取文件列表失败");
                }
            });
        }

        // 上传文件
        function uploadFile() {
            var fileInput = document.getElementById('fileInput');
            var file = fileInput.files[0];

            var formData = new FormData();
            formData.append("file", file);

            $.ajax({
                url: "/file/upload",
                type: "POST",
                data: formData,
                processData: false,
                contentType: false,
                success: function () {
                    alert("上传成功");
                    getFileList(1, 10); // 刷新文件列表
                },
                error: function () {
                    alert("上传失败");
                }
            });
        }

        // 删除文件
        function deleteFile() {
            var filenameInput = document.getElementById('filenameInput');
            var filename = filenameInput.value;

            $.ajax({
                url: "/file/delete",
                type: "DELETE",
                data: {
                    filename: filename
                },
                success: function () {
                    alert("删除成功");
                    getFileList(1, 10); // 刷新文件列表
                },
                error: function () {
                    alert("删除失败");
                }
            });
        }

        getFileList(1, 10); // 页面加载时获取文件列表
    </script>
</body>
</html>

以上是一个使用SSM框架实现分页展示HDFS文件列表、上传文件、删除文件、下载文件的前后端代码示例。请根据实际需求进行适当修改和补充。

### 回答3：
SSM框架通常用于开发JavaWeb项目，其中S为Spring、S为SpringMVC、M为MyBatis。下面将介绍如何使用SSM框架进行HDFS文件列表的分页展示、文件的上传、删除和下载的前后端代码。

1. 后端Java代码：
- 定义文件列表的数据模型：

public class HdfsFile {
    private String name;
    private String path;
    // get、set方法省略
}

- 编写文件列表的服务类：

@Service
public class HdfsFileService {
    @Autowired
    private FileSystem fs;

    public List<HdfsFile> getFileList(String path, int pageNum, int pageSize) throws IOException {
        List<HdfsFile> fileList = new ArrayList<>();
        // 使用HDFS API获取指定路径下的文件列表，可通过FileSystem类的globStatus或listFiles方法实现
        // 将获取的文件列表转换为HdfsFile对象，设置name和path属性
        // 根据pageNum和pageSize进行分页处理
        // 返回分页结果
        return fileList;
    }

    public void uploadFile(String localPath, String hdfsPath) throws IOException {
        // 使用HDFS API将本地文件上传至HDFS，可通过FileSystem类的copyFromLocalFile方法实现
    }

    public void deleteFile(String hdfsPath) throws IOException {
        // 使用HDFS API删除HDFS中的文件，可通过FileSystem类的delete方法实现
    }

    public void downloadFile(String hdfsPath, String localPath) throws IOException {
        // 使用HDFS API从HDFS下载文件到本地，可通过FileSystem类的copyToLocalFile方法实现
    }
}

- 编写后端Controller类：

@Controller
@RequestMapping("/hdfs")
public class HdfsFileController {
    @Autowired
    private HdfsFileService hdfsFileService;

    @RequestMapping("/list")
    @ResponseBody
    public List<HdfsFile> getFileList(String path, int pageNum, int pageSize) throws IOException {
        return hdfsFileService.getFileList(path, pageNum, pageSize);
    }

    @RequestMapping("/upload")
    @ResponseBody
    public void uploadFile(String localPath, String hdfsPath) throws IOException {
        hdfsFileService.uploadFile(localPath, hdfsPath);
    }

    @RequestMapping("/delete")
    @ResponseBody
    public void deleteFile(String hdfsPath) throws IOException {
        hdfsFileService.deleteFile(hdfsPath);
    }

    @RequestMapping("/download")
    @ResponseBody
    public void downloadFile(String hdfsPath, String localPath) throws IOException {
        hdfsFileService.downloadFile(hdfsPath, localPath);
    }
}

2. 前端代码：
- 分页展示HDFS文件列表的页面：

<!DOCTYPE html>
<html>
<head>
    <title>HDFS文件列表</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
</head>
<body>
    <div id="fileListContainer"></div>
    <script>
        var pageNum = 1;
        var pageSize = 10;

        function getFileList() {
            $.ajax({
                url: "/hdfs/list",
                type: "get",
                data: {
                    path: "/",
                    pageNum: pageNum,
                    pageSize: pageSize
                },
                success: function (data) {
                    var fileListContainer = $("#fileListContainer");
                    fileListContainer.empty();
                    for (var i = 0; i < data.length; i++) {
                        var file = data[i];
                        fileListContainer.append("<div>" + file.name + "</div>");
                    }
                }
            });
        }

        $(document).ready(function () {
            getFileList();
        });
    </script>
</body>
</html>

- 上传文件的页面：

<!DOCTYPE html>
<html>
<head>
    <title>上传文件</title>
</head>
<body>
    <input type="file" id="fileInput">
    <button onclick="uploadFile()">上传</button>
    <script>
        function uploadFile() {
            var fileInput = document.getElementById("fileInput");
            var file = fileInput.files[0];
            var formData = new FormData();
            formData.append("file", file);

            $.ajax({
                url: "/hdfs/upload",
                type: "post",
                data: formData,
                processData: false,
                contentType: false,
                success: function () {
                    alert("文件上传成功");
                }
            });
        }
    </script>
</body>
</html>

- 删除文件的页面：

<!DOCTYPE html>
<html>
<head>
    <title>删除文件</title>
</head>
<body>
    <input type="text" id="hdfsPathInput">
    <button onclick="deleteFile()">删除</button>
    <script>
        function deleteFile() {
            var hdfsPath = document.getElementById("hdfsPathInput").value;

            $.ajax({
                url: "/hdfs/delete",
                type: "post",
                data: {
                    hdfsPath: hdfsPath
                },
                success: function () {
                    alert("文件删除成功");
                }
            });
        }
    </script>
</body>
</html>

- 下载文件的页面：

<!DOCTYPE html>
<html>
<head>
    <title>下载文件</title>
</head>
<body>
    <input type="text" id="hdfsPathInput">
    <input type="text" id="localPathInput">
    <button onclick="downloadFile()">下载</button>
    <script>
        function downloadFile() {
            var hdfsPath = document.getElementById("hdfsPathInput").value;
            var localPath = document.getElementById("localPathInput").value;

            $.ajax({
                url: "/hdfs/download",
                type: "post",
                data: {
                    hdfsPath: hdfsPath,
                    localPath: localPath
                },
                success: function () {
                    alert("文件下载成功");
                }
            });
        }
    </script>
</body>
</html>

以上就是使用SSM框架进行HDFS文件列表的分页展示、上传、删除和下载的前后端代码。具体实现还需要根据实际情况进行调整和完善。