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

1. 分页展示Hdfs文件列表

前端代码：

<!-- 分页插件 -->
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

<table class="table table-hover">
    <thead>
        <tr>
            <th>#</th>
            <th>文件名</th>
            <th>大小</th>
            <th>修改时间</th>
            <th>操作</th>
        </tr>
    </thead>
    <tbody>
        <c:forEach items="${hdfsFiles}" var="hdfsFile" varStatus="status">
            <tr>
                <td>${status.index+1}</td>
                <td><a href="#">${hdfsFile.name}</a></td>
                <td>${hdfsFile.size}</td>
                <td>${hdfsFile.modificationTime}</td>
                <td>
                    <button class="btn btn-danger" onclick="deleteFile('${hdfsFile.path}')">删除</button>
                    <button class="btn btn-success" onclick="downloadFile('${hdfsFile.path}')">下载</button>
                </td>
            </tr>
        </c:forEach>
    </tbody>
</table>

<div class="text-center">
    <ul class="pagination">
        <c:choose>
            <c:when test="${pageInfo.pageNum == 1}">
                <li class="disabled"><a href="#">首页</a></li>
                <li class="disabled"><a href="#">上一页</a></li>
            </c:when>
            <c:otherwise>
                <li><a href="?pageNum=1">首页</a></li>
                <li><a href="?pageNum=${pageInfo.prePage}">上一页</a></li>
            </c:otherwise>
        </c:choose>

        <c:forEach begin="${pageInfo.navigateFirstPage}" end="${pageInfo.navigateLastPage}" var="i">
            <c:choose>
                <c:when test="${i == pageInfo.pageNum}">
                    <li class="active"><a href="#">${i}</a></li>
                </c:when>
                <c:otherwise>
                    <li><a href="?pageNum=${i}">${i}</a></li>
                </c:otherwise>
            </c:choose>
        </c:forEach>

        <c:choose>
            <c:when test="${pageInfo.pageNum == pageInfo.pages}">
                <li class="disabled"><a href="#">下一页</a></li>
                <li class="disabled"><a href="#">尾页</a></li>
            </c:when>
            <c:otherwise>
                <li><a href="?pageNum=${pageInfo.nextPage}">下一页</a></li>
                <li><a href="?pageNum=${pageInfo.pages}">尾页</a></li>
            </c:otherwise>
        </c:choose>
    </ul>
</div>

后端代码：

@RequestMapping("/listFiles")
public ModelAndView listFiles(@RequestParam(defaultValue = "1") Integer pageNum, @RequestParam(defaultValue = "10") Integer pageSize) throws Exception {
    ModelAndView mv = new ModelAndView("fileList");
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), new Configuration(), "root");
    RemoteIterator<LocatedFileStatus> fileStatusListIterator = fs.listFiles(new Path("/"), true);
    List<HdfsFile> hdfsFiles = new ArrayList<>();
    while (fileStatusListIterator.hasNext()) {
        LocatedFileStatus fileStatus = fileStatusListIterator.next();
        HdfsFile hdfsFile = new HdfsFile();
        hdfsFile.setName(fileStatus.getPath().getName());
        hdfsFile.setPath(fileStatus.getPath().toString());
        hdfsFile.setSize(fileStatus.getLen());
        hdfsFile.setModificationTime(fileStatus.getModificationTime());
        hdfsFiles.add(hdfsFile);
    }
    PageHelper.startPage(pageNum, pageSize);
    PageInfo<HdfsFile> pageInfo = new PageInfo<>(hdfsFiles);
    mv.addObject("hdfsFiles", pageInfo.getList());
    mv.addObject("pageInfo", pageInfo);
    return mv;
}

2. 上传文件

前端代码：

<form action="${pageContext.request.contextPath}/uploadFile" method="post" enctype="multipart/form-data">
    <div class="form-group">
        <label>选择文件</label>
        <input type="file" name="file">
    </div>
    <button type="submit" class="btn btn-primary">上传</button>
</form>

后端代码：

@RequestMapping("/uploadFile")
public String uploadFile(@RequestParam("file") MultipartFile file) throws IOException, URISyntaxException {
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), new Configuration(), "root");
    Path dst = new Path("/" + file.getOriginalFilename());
    FSDataOutputStream outputStream = fs.create(dst);
    IOUtils.copyBytes(file.getInputStream(), outputStream, 4096, true);
    return "redirect:/listFiles";
}

3. 删除文件

前端代码：

<button class="btn btn-danger" onclick="deleteFile('${hdfsFile.path}')">删除</button>

后端代码：

@RequestMapping("/deleteFile")
public String deleteFile(String path) throws IOException, URISyntaxException {
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), new Configuration(), "root");
    Path dst = new Path(path);
    fs.delete(dst, true);
    return "redirect:/listFiles";
}

4. 下载文件

前端代码：

<button class="btn btn-success" onclick="downloadFile('${hdfsFile.path}')">下载</button>

后端代码：

@RequestMapping("/downloadFile")
public ResponseEntity<byte[]> downloadFile(String path) throws IOException, URISyntaxException {
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), new Configuration(), "root");
    Path dst = new Path(path);
    FSDataInputStream inputStream = fs.open(dst);
    byte[] bytes = IOUtils.toByteArray(inputStream);
    HttpHeaders headers = new HttpHeaders();
    headers.setContentDispositionFormData("attachment", dst.getName());
    headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
    return new ResponseEntity<>(bytes, headers, HttpStatus.CREATED);
}