javaSSM框架展示HDFS文件列表，上传文件，删除文件，下载文件前后端代码

以下是Java SSM框架展示HDFS文件列表、上传文件、删除文件、下载文件前后端代码的示例：

1. 展示HDFS文件列表

后端代码：

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

    @Autowired
    private FileSystem fs;

    @RequestMapping("/list")
    @ResponseBody
    public List<String> listFiles(String path) throws IOException {
        if (StringUtils.isBlank(path)) {
            path = "/";
        }
        Path hdfsPath = new Path(path);
        RemoteIterator<LocatedFileStatus> fileStatusRemoteIterator = fs.listFiles(hdfsPath, true);
        List<String> fileList = new ArrayList<>();
        while (fileStatusRemoteIterator.hasNext()) {
            LocatedFileStatus fileStatus = fileStatusRemoteIterator.next();
            fileList.add(fileStatus.getPath().toString());
        }
        return fileList;
    }
}

前端代码：

<script>
    $.ajax({
        url: "/hdfs/list",
        type: "get",
        data: {
            path: "/"
        },
        success: function (data) {
            var html = "";
            for (var i = 0; i < data.length; i++) {
                html += "<div>" + data[i] + "</div>";
            }
            $("#file-list").html(html);
        }
    });
</script>
<div id="file-list"></div>

2. 上传文件

后端代码：

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

    @Autowired
    private FileSystem fs;

    @RequestMapping("/upload")
    @ResponseBody
    public String uploadFile(MultipartFile file, String path) throws IOException {
        if (StringUtils.isBlank(path)) {
            path = "/";
        }
        Path hdfsPath = new Path(path);
        FSDataOutputStream outputStream = fs.create(hdfsPath);
        IOUtils.copy(file.getInputStream(), outputStream);
        outputStream.close();
        return "success";
    }
}

前端代码：

<form id="upload-form">
    <input type="file" name="file"/>
    <input type="text" name="path" value="/"/>
    <button type="submit">上传</button>
</form>
<script>
    $("#upload-form").submit(function (event) {
        event.preventDefault();
        var formData = new FormData(this);
        $.ajax({
            url: "/hdfs/upload",
            type: "post",
            data: formData,
            processData: false,
            contentType: false,
            success: function (data) {
                alert("上传成功");
            }
        });
    });
</script>

3. 删除文件

后端代码：

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

    @Autowired
    private FileSystem fs;

    @RequestMapping("/delete")
    @ResponseBody
    public String deleteFile(String path) throws IOException {
        if (StringUtils.isBlank(path)) {
            return "path is empty";
        }
        Path hdfsPath = new Path(path);
        boolean result = fs.delete(hdfsPath, true);
        if (result) {
            return "success";
        } else {
            return "fail";
        }
    }
}

前端代码：

<form id="delete-form">
    <input type="text" name="path" value="/"/>
    <button type="submit">删除</button>
</form>
<script>
    $("#delete-form").submit(function (event) {
        event.preventDefault();
        var path = $(this).find("input[name=path]").val();
        $.ajax({
            url: "/hdfs/delete",
            type: "post",
            data: {
                path: path
            },
            success: function (data) {
                if (data == "success") {
                    alert("删除成功");
                } else {
                    alert("删除失败");
                }
            }
        });
    });
</script>

4. 下载文件

后端代码：

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

    @Autowired
    private FileSystem fs;

    @RequestMapping("/download")
    public void downloadFile(HttpServletResponse response, String path) throws IOException {
        if (StringUtils.isBlank(path)) {
            return;
        }
        Path hdfsPath = new Path(path);
        FSDataInputStream inputStream = fs.open(hdfsPath);
        OutputStream outputStream = response.getOutputStream();
        IOUtils.copy(inputStream, outputStream);
        inputStream.close();
        outputStream.flush();
    }
}

前端代码：

<a href="/hdfs/download?path=/test.txt">下载</a>