hdfs上传文件代码

在Hadoop分布式文件系统（HDFS）中，上传文件通常使用Hadoop的命令行工具Hadoop File System (HDFS) Client，或者通过编程方式使用Hadoop的API。这里我将演示一个基本的通过Hadoop命令行上传文件的步骤[^4]：

# 假设你已经登录到Hadoop集群并切换到HDFS用户
hadoop fs -put <本地文件路径> <HDFS文件路径>

例如，如果你要将本地的`/home/user/myfile.txt`上传到HDFS的`/user/hdfs/destination`目录，命令会是：

hadoop fs -put /home/user/myfile.txt /user/hdfs/destination/myfile.txt

这将会把`myfile.txt`复制到HDFS指定的位置。

如果你想通过编程方式，如Java，可以使用`FileSystem`接口[^5]。例如：

Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path localFile = new Path("/path/to/local/file");
Path hdfsFile = new Path("/path/in/hdfs/file");
fs.copyFromLocalFile(localFile, hdfsFile);

相关问题

hdfs上传文件的代码

在Hadoop分布式文件系统（HDFS）上上传文件通常涉及到使用Hadoop的API或者命令行工具`hadoop fs`。这里是一个简单的Java示例，展示了如何使用Apache Hadoop的FileSystem API来上传文件：

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

public class HdfsFileUploader {
    public static void main(String[] args) throws Exception {
        // 设置HDFS配置
        Configuration conf = new Configuration();
        String hdfsUrl = "your_hdfs_namenode_url"; // 例如：hdfs://localhost:9000
        FileSystem fs = FileSystem.get(conf);

        // 指定要上传的本地文件路径
        Path localFilePath = new Path("path_to_your_local_file");
        
        // 指定HDFS的目标路径
        Path hdfsTargetPath = new Path(hdfsUrl + "/path/to/upload/in/hdfs");

        // 使用FSDataOutputStream将文件写入HDFS
        fs.copyFromLocalFile(localFilePath, hdfsTargetPath);

        System.out.println("File uploaded successfully to " + hdfsTargetPath);
        fs.close(); // 关闭连接
    }
}

在这个例子中，你需要替换`your_hdfs_namenode_url`为你实际Hadoop集群的NameNode地址，并指定本地文件和目标HDFS路径。

如果你使用的是命令行工具，你可以这样做：

hadoop dfs -put /path/to/local/file /path/to/upload/in/hdfs

这会将`local/file`复制到HDFS的`/path/to/upload/in/hdfs`目录下。

ssm查看hdfs文件，上传文件，下载文件，删除文件前后端代码

### 回答1：
以下是SSM框架中查看、上传、下载、删除HDFS文件的前后端代码。

### 查看HDFS文件

前端代码：

<!-- index.jsp -->
<form id="form" enctype="multipart/form-data" method="post" action="showFile">
  <label for="path">文件路径：</label>
  <input type="text" name="path" id="path">
  <input type="submit" value="查看">
</form>

后端代码：

// FileController.java
@Controller
public class FileController {
    private final FileSystem fileSystem = HdfsUtil.getFileSystem();
    
    @RequestMapping("showFile")
    @ResponseBody
    public String showFile(@RequestParam("path") String path) {
        try {
            FSDataInputStream inputStream = fileSystem.open(new Path(path));
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuilder builder = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                builder.append(line).append("\n");
            }
            reader.close();
            inputStream.close();
            return builder.toString();
        } catch (IOException e) {
            e.printStackTrace();
            return "读取文件失败！";
        }
    }
}

### 上传HDFS文件

前端代码：

<!-- index.jsp -->
<form id="form" enctype="multipart/form-data" method="post" action="uploadFile">
  <label for="file">上传文件：</label>
  <input type="file" name="file" id="file">
  <input type="submit" value="上传">
</form>

后端代码：

// FileController.java
@Controller
public class FileController {
    private final FileSystem fileSystem = HdfsUtil.getFileSystem();
    
    @RequestMapping("uploadFile")
    @ResponseBody
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        try {
            String fileName = file.getOriginalFilename();
            Path path = new Path("/" + fileName);
            FSDataOutputStream outputStream = fileSystem.create(path);
            outputStream.write(file.getBytes());
            outputStream.close();
            return "文件上传成功！";
        } catch (IOException e) {
            e.printStackTrace();
            return "文件上传失败！";
        }
    }
}

### 下载HDFS文件

前端代码：

<!-- index.jsp -->
<form id="form" enctype="multipart/form-data" method="post" action="downloadFile">
  <label for="path">文件路径：</label>
  <input type="text" name="path" id="path">
  <input type="submit" value="下载">
</form>

后端代码：

// FileController.java
@Controller
public class FileController {
    private final FileSystem fileSystem = HdfsUtil.getFileSystem();
    
    @RequestMapping("downloadFile")
    public void downloadFile(@RequestParam("path") String path, HttpServletResponse response) {
        try {
            FSDataInputStream inputStream = fileSystem.open(new Path(path));
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment; filename=" + new Path(path).getName());
            IOUtils.copyBytes(inputStream, response.getOutputStream(), 4096, false);
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

### 删除HDFS文件

前端代码：

<!-- index.jsp -->
<form id="form" enctype="multipart/form-data" method="post" action="deleteFile">
  <label for="path">文件路径：</label>
  <input type="text" name="path" id="path">
  <input type="submit" value="删除">
</form>

后端代码：

// FileController.java
@Controller
public class FileController {
    private final FileSystem fileSystem = HdfsUtil.getFileSystem();
    
    @RequestMapping("deleteFile")
    @ResponseBody
    public String deleteFile(@RequestParam("path") String path) {
        try {
            boolean result = fileSystem.delete(new Path(path), true);
            return result ? "文件删除成功！" : "文件删除失败！";
        } catch (IOException e) {
            e.printStackTrace();
            return "文件删除失败！";
        }
    }
}

其中，`HdfsUtil`是一个工具类，用于获取HDFS的FileSystem实例。具体实现可参考以下代码：

// HdfsUtil.java
public class HdfsUtil {
    private static final String HDFS_URI = "hdfs://localhost:9000";
    private static final Configuration CONFIGURATION = new Configuration();
    private static FileSystem fileSystem;

    static {
        try {
            fileSystem = FileSystem.get(URI.create(HDFS_URI), CONFIGURATION);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static FileSystem getFileSystem() {
        return fileSystem;
    }
}

### 回答2：
为了实现SSM查看HDFS文件、上传文件、下载文件、删除文件的功能，我们需要在前后端代码中分别实现相应的操作。

首先，后端代码：
1. 查看HDFS文件：

@Controller
@RequestMapping("/hdfs")
public class HdfsController {
    @Autowired
    private HdfsService hdfsService;

    @GetMapping("/view") 
    @ResponseBody
    public List<String> viewHdfsFiles() {
        return hdfsService.getHdfsFiles();
    }
}

2. 上传文件：

@Controller
@RequestMapping("/hdfs")
public class HdfsController {
    @Autowired
    private HdfsService hdfsService;

    @PostMapping("/upload")
    @ResponseBody
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        return hdfsService.uploadFile(file);
    }
}

3. 下载文件：

@Controller
@RequestMapping("/hdfs")
public class HdfsController {
    @Autowired
    private HdfsService hdfsService;

    @GetMapping("/download")
    public ResponseEntity<Resource> downloadFile(@RequestParam("path") String path) {
        return hdfsService.downloadFile(path);
    }
}

4. 删除文件：

@Controller
@RequestMapping("/hdfs")
public class HdfsController {
    @Autowired
    private HdfsService hdfsService;

    @GetMapping("/delete")
    @ResponseBody
    public String deleteFile(@RequestParam("path") String path) {
        return hdfsService.deleteFile(path);
    }
}

然后，前端代码：
1. 查看HDFS文件：

<script>
    $(document).ready(function() {
        $.ajax({
            url: "/hdfs/view",
            type: "GET",
            success: function(data) {
                // 处理返回的文件列表data
            }
        });
    });
</script>

2. 上传文件：

<form id="uploadForm" method="POST" enctype="multipart/form-data">
    <input type="file" name="file" accept=".txt,.csv">
    <button type="submit">上传</button>
</form>

<script>
    $("#uploadForm").submit(function(e) {
        e.preventDefault();
        var formData = new FormData(this);
        $.ajax({
            url: "/hdfs/upload",
            type: "POST",
            data: formData,
            contentType: false,
            processData: false,
            success: function(data) {
                // 处理上传结果data
            }
        });
    });
</script>

3. 下载文件：

<input type="text" id="downloadPath">
<button onclick="downloadFile()">下载</button>

<script>
    function downloadFile() {
        var path = $("#downloadPath").val();
        window.open("/hdfs/download?path=" + path);
    }
</script>

4. 删除文件：

<input type="text" id="deletePath">
<button onclick="deleteFile()">删除</button>

<script>
    function deleteFile() {
        var path = $("#deletePath").val();
        $.ajax({
            url: "/hdfs/delete?path=" + path,
            type: "GET",
            success: function(data) {
                // 处理删除结果data
            }
        });
    }
</script>

以上就是SSM查看HDFS文件、上传文件、下载文件、删除文件的前后端代码实现。请根据实际情况进行适当的修改和调整。

### 回答3：
以下是一个简单的SSM项目的前后端代码，实现了查看HDFS文件、上传文件、下载文件、删除文件的功能。

后端代码：

1. HDFSUtil.java

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.springframework.stereotype.Component;

import java.io.InputStream;
import java.io.OutputStream;

@Component
public class HDFSUtil {

    private Configuration configuration;
    private FileSystem fileSystem;

    public HDFSUtil() throws Exception {
        configuration = new Configuration();
        configuration.set("fs.defaultFS", "hdfs://localhost:9000"); // 设置HDFS地址
        fileSystem = FileSystem.get(configuration);
    }

    public void close() throws Exception {
        if (fileSystem != null) {
            fileSystem.close();
        }
    }

    public void uploadFile(InputStream inputStream, String destPath) throws Exception {
        OutputStream outputStream = fileSystem.create(new Path(destPath));
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }
        outputStream.close();
        inputStream.close();
    }

    public void downloadFile(String srcPath, OutputStream outputStream) throws Exception {
        InputStream inputStream = fileSystem.open(new Path(srcPath));
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }
        outputStream.close();
        inputStream.close();
    }

    public void deleteFile(String path) throws Exception {
        fileSystem.delete(new Path(path), true);
    }
}

2. FileController.java

import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

@Controller
@RequestMapping("/file")
public class FileController {

    @Autowired
    private HDFSUtil hdfsUtil;

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    @ResponseBody
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        try {
            InputStream inputStream = file.getInputStream();
            hdfsUtil.uploadFile(inputStream, "/hdfs/path/" + file.getOriginalFilename());
            inputStream.close();
            return "上传成功";
        } catch (Exception e) {
            e.printStackTrace();
            return "上传失败";
        }
    }

    @RequestMapping(value = "/download", method = RequestMethod.GET)
    public void downloadFile(@RequestParam("path") String path, HttpServletResponse response) {
        try {
            OutputStream outputStream = response.getOutputStream();
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment; filename=\"" + path + "\"");
            hdfsUtil.downloadFile("/hdfs/path/" + path, outputStream);
            outputStream.flush();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @RequestMapping(value = "/delete", method = RequestMethod.DELETE)
    @ResponseBody
    public String deleteFile(@RequestParam("path") String path) {
        try {
            hdfsUtil.deleteFile("/hdfs/path/" + path);
            return "删除成功";
        } catch (Exception e) {
            e.printStackTrace();
            return "删除失败";
        }
    }

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    @ResponseBody
    public String listFiles() {
        try {
            // 使用HDFS API获取文件列表
            // ...
            return "文件列表";
        } catch (Exception e) {
            e.printStackTrace();
            return "获取文件列表失败";
        }
    }
}

前端代码：

1. upload.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>HDFS文件上传</title>
</head>
<body>
<form method="post" enctype="multipart/form-data" action="/file/upload">
    <input type="file" name="file"/>
    <button type="submit">上传</button>
</form>
</body>
</html>

2. download.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>HDFS文件下载</title>
</head>
<body>
<a href="/file/download?path=filename">下载</a>
</body>
</html>

3. delete.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>HDFS文件删除</title>
</head>
<body>
<form method="post" action="/file/delete">
    <input type="text" name="path"/>
    <button type="submit">删除</button>
</form>
</body>
</html>

注意：上述代码中的文件路径 "/hdfs/path/" 需要根据实际的HDFS路径进行修改。另外，还需要添加相应的依赖，如Spring MVC、Spring、MyBatis、Hadoop HDFS等。