hadoop文件系统操作(2)

来源：互联网发布：斗战神精炼软件编辑：程序博客网时间：2024/06/05 19:49

常见HDFS文件系统操作

（1）ls操作，查看文件的状态

    public void ls(String folder) throws IOException {        Path path = new Path(folder);        FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);        FileStatus[] list = fs.listStatus(path);        System.out.println("ls: " + folder);        System.out.println("==========================================================");        for (FileStatus f : list) {            System.out.printf("name: %s, folder: %s, size: %d\n", f.getPath(), f.isDir(), f.getLen());        }        System.out.println("==========================================================");        fs.close();    }

（2）rm -r操作

 public void rm(String folder) throws IOException {        Path path = new Path(folder);        FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);        fs.deleteOnExit(path);        System.out.println("Delete: " + folder);        fs.close();    }

（3）copyFromLocal操作：

 public void copyFile(String local, String remote) throws IOException {        FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);        fs.copyFromLocalFile(new Path(local), new Path(remote));        System.out.println("copy from: " + local + " to " + remote);        fs.close();    }

（4）显示文件内容操作：

 public void cat(String remoteFile) throws IOException {        Path path = new Path(remoteFile);        FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);        FSDataInputStream fsdis = null;        System.out.println("cat: " + remoteFile);        try {              fsdis =fs.open(path);            IOUtils.copyBytes(fsdis, System.out, 4096, false);            } finally {              IOUtils.closeStream(fsdis);            fs.close();          }    }

(5)download操作：

 public void download(String remote, String local) throws IOException {        Path path = new Path(remote);        FileSystem fs = FileSystem.get(URI.create(hdfsPath), conf);        fs.copyToLocalFile(path, new Path(local));        System.out.println("download: from" + remote + " to " + local);        fs.close();    }

0 0