//创建目录

    public static void mkdir(String filePath) throws URISyntaxException, IOException, InterruptedException{

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path path= new Path(filePath);

        fs.mkdirs(path);

        System.out.println("目录创建成功："+filePath);

        fs.close();

    }

//创建文件

    public static void createFile(String remoteFilePath)throws URISyntaxException, IOException, InterruptedException {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path remotePath = new Path(remoteFilePath);

        FSDataOutputStream outputStream = fs.create(remotePath);

        outputStream.close();

        System.out.println("文件创建成功！！"+remoteFilePath);

    }

//删除文件

    public static void deleteFile(String filePath) throws URISyntaxException, IOException, InterruptedException{

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path path= new Path(filePath);

        if(fs.deleteOnExit(path)) {

            System.out.println("文件删除成功："+filePath);

        } else {

            System.out.println("文件删除失败："+filePath);

        }

        fs.close();

    }

 // 移动文件到本地

    public static void moveToLocalFile(String remoteFilePath, String localFilePath) throws IOException, InterruptedException, URISyntaxException {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path remotePath = new Path(remoteFilePath);

        Path localPath = new Path(localFilePath);

        fs.moveToLocalFile(remotePath, localPath);

    }

//显示文件内容

    public static void cat(String file)throws URISyntaxException, IOException, InterruptedException

    {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path filePath = new Path(file);

        if(fs.exists(filePath)) {

            FSDataInputStream in = fs.open(filePath);

            BufferedReader br = new BufferedReader(new InputStreamReader(in));

            String content = null;

            while((content = br.readLine()) != null) {

                System.out.println(content);

            }

            br.close();

            fs.close();

        }else {

            System.out.println("file "+filePath+ "doesn't exist.");

        }

        fs.close();

    }

//移动hdfs中的文件

    public static void moveFile(String srcPath, String dirPath) throws URISyntaxException, IOException, InterruptedException {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        if(fs.exists(new Path(dirPath))) {

            System.out.println("文件被占用。");

            return;

        }

        if(fs.rename(new Path(srcPath), new Path(dirPath))) {

            System.out.println("文件移动成功。");

        } else {

            System.out.println("文件移动失败。");

        }

    }

//将本地文件上传到hdfs

    public static void copyFromLocalFile(String localPath,String srcPath) throws URISyntaxException, IOException, InterruptedException

    {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        fs.copyFromLocalFile(new Path(localPath),new Path(srcPath));

        System.out.println("上传成功！！！");

        fs.close();

    }

    //将hdfs的文件下载到本地

    public static void downFromHdfs(String src,String dst)throws URISyntaxException, IOException, InterruptedException

    {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path dstPath=new Path(dst);

        //第一个参数为：是否删除原文件，源文件，目的文件，是否使用本地文件系统

        fs.copyToLocalFile(false,new Path(src),dstPath,true);

        fs.close();

        System.out.println("文件下载成功已存放到"+dst);

    }

//追加到结尾

    public static void addContentToTail(String filePath, String content, boolean head) throws IOException, InterruptedException, URISyntaxException {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path path= new Path(filePath);

        FSDataOutputStream ops = fs.append(path);

        ops.write(content.getBytes());

        if (!head) {

            System.out.println("内容以追加到结尾。");

        }

        ops.close();

        fs.close();

    }

 // 追加本地文件内容到目的文件结尾

    public static void addFileToTail(String localFilePath, String remoteFilePath) throws IOException, InterruptedException, URISyntaxException{

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path remotePath = new Path(remoteFilePath);

        // 创建一个本地文件(需要追加的文件)读入流

        FileInputStream inps = new FileInputStream(localFilePath);

        // 创建一个文件输出留，输出的内容追加到文件末尾

        FSDataOutputStream ops = fs.append(remotePath);

        byte[] buffer = new byte[1024];

        int read = -1;

        while((read = inps.read(buffer)) > 0) {

            ops.write(buffer, 0, read);

        }

        ops.close();

        inps.close();

        fs.close();

    }

// 追加内容到文件开头

    public static void addContentToHead(String filePath, String content) throws IOException, InterruptedException, URISyntaxException {

        // 创建一个临时本地文件

        String localFilePath = new File("").getCanonicalPath()+"\\web\\text\\xlf.txt" ;

        // 将要追加的文件移动到本地

        moveToLocalFile(filePath, localFilePath);

        // 创建一个新的HDFS文件（空的）

        createFile(filePath);

        appendContentToTail(content,filePath, true);

        addFileToTail(localFilePath, filePath);

        System.out.println("内容以追加到开头。");

    }

public  static void existandcreat(String path) throws URISyntaxException, IOException, InterruptedException {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path path1=new Path(path);

        if(fs.exists(path1))

        {

            System.out.println("存在！！");

        }

        else

        {

            FSDataOutputStream ops=fs.create(path1);

            ops.close();

            fs.close();

        }

    }

/*查看当前目录下的文件信息*/

    public static void printfile(String file)throws URISyntaxException, IOException, InterruptedException

    {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        FileStatus[] statuses=fs.listStatus(new Path(file));

        for(FileStatus s:statuses)

        {

            System.out.println("读写权限："+s.getPermission()+"; 文件大小："+s.getBlockSize()+"; 文件路径："

                    +s.getPath()+"; 文件创建时间："+s.getModificationTime());

        }

        fs.close();

    }

    /*递归查看目录下的文件信息*/

    public static void prinfileInfo(String file)throws URISyntaxException, IOException, InterruptedException

    {

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop101:8020"), new Configuration(), "root");

        Path path= new Path(file);

        RemoteIterator<LocatedFileStatus> iterator = fs.listFiles(path, true);

        while(iterator.hasNext()) {

            FileStatus s = iterator.next();

            System.out.println("读写权限："+s.getPermission()+"; 文件大小："+s.getBlockSize()+"; 文件路径："

                    +s.getPath()+"; 文件创建时间："+s.getModificationTime());

        }

        fs.close();

    }