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

这里只提供简单的代码示例供参考，具体实现需要根据自己的实际情况进行调整。

展示HDFS文件列表：

后端代码：

@RequestMapping("/listHdfsFiles")
@ResponseBody
public List<String> listHdfsFiles() throws Exception {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), conf);
    RemoteIterator<LocatedFileStatus> files = fs.listFiles(new Path("/"), true);
    List<String> fileList = new ArrayList<>();
    while (files.hasNext()) {
        LocatedFileStatus file = files.next();
        fileList.add(file.getPath().toString());
    }
    return fileList;
}

前端代码：

<script>
    $(document).ready(function () {
        $.ajax({
            type: "GET",
            url: "/listHdfsFiles",
            success: function (data) {
                for (var i = 0; i < data.length; i++) {
                    $("#fileList").append("<li>" + data[i] + "</li>");
                }
            },
            error: function (xhr, status, error) {
                console.log(xhr.responseText);
            }
        });
    });
</script>
<ul id="fileList"></ul>

上传文件：

后端代码：

@RequestMapping(value = "/uploadHdfsFile", method = RequestMethod.POST)
@ResponseBody
public String uploadHdfsFile(@RequestParam("file") MultipartFile file) throws Exception {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), conf);
    Path path = new Path("/" + file.getOriginalFilename());
    FSDataOutputStream outputStream = fs.create(path);
    outputStream.write(file.getBytes());
    outputStream.close();
    return "success";
}

前端代码：

<form id="uploadForm" enctype="multipart/form-data">
    <input type="file" name="file" /><br/>
    <input type="button" value="上传" onclick="uploadFile()" />
</form>
<script>
    function uploadFile() {
        var formData = new FormData($("#uploadForm")[0]);
        $.ajax({
            type: "POST",
            url: "/uploadHdfsFile",
            data: formData,
            processData: false,
            contentType: false,
            success: function (data) {
                console.log(data);
            },
            error: function (xhr, status, error) {
                console.log(xhr.responseText);
            }
        });
    }
</script>

删除文件：

后端代码：

@RequestMapping(value = "/deleteHdfsFile", method = RequestMethod.POST)
@ResponseBody
public String deleteHdfsFile(@RequestParam("filePath") String filePath) throws Exception {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), conf);
    Path path = new Path(filePath);
    fs.delete(path, false);
    return "success";
}

前端代码：

function deleteFile(filePath) {
    $.ajax({
        type: "POST",
        url: "/deleteHdfsFile",
        data: {"filePath": filePath},
        success: function (data) {
            console.log(data);
        },
        error: function (xhr, status, error) {
            console.log(xhr.responseText);
        }
    });
}

下载文件：

后端代码：

@RequestMapping(value = "/downloadHdfsFile", method = RequestMethod.POST)
@ResponseBody
public void downloadHdfsFile(@RequestParam("filePath") String filePath, HttpServletResponse response) throws Exception {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"), conf);
    Path path = new Path(filePath);
    FSDataInputStream inputStream = fs.open(path);
    OutputStream outputStream = response.getOutputStream();
    IOUtils.copyBytes(inputStream, outputStream, conf);
    inputStream.close();
    outputStream.close();
}

前端代码：

function downloadFile(filePath) {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "/downloadHdfsFile", true);
    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    xhr.responseType = "blob";
    xhr.onload = function () {
        var blob = this.response;
        var a = document.createElement("a");
        var url = window.URL.createObjectURL(blob);
        a.href = url;
        a.download = filePath.substring(filePath.lastIndexOf("/") + 1);
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        window.URL.revokeObjectURL(url);
    };
    xhr.send("filePath=" + filePath);
}