HDFS基本常用命令是什么
这篇文章主要介绍了HDFS基本常用命令是什么,具有一定借鉴价值,感兴趣的朋友可以参考下,希望大家阅读完这篇文章之后大有收获,下面让小编带着大家一起了解一下。
成都创新互联坚持“要么做到,要么别承诺”的工作理念,服务领域包括:网站制作、网站设计、企业官网、英文网站、手机端网站、网站推广等服务,满足客户于互联网时代的札达网站设计、移动媒体设计的需求,帮助企业找到有效的互联网解决方案。努力成为您成熟可靠的网络建设合作伙伴!
一. 创建HDFS文件:
public class Test4CreateFile { /** * 创建HDFS文件: * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); byte[] buff = "Hello Hadoop HDFS".getBytes(); FileSystem fs = FileSystem.get(uri, conf); Path dfs = new Path("hdfs://192.168.226.129:9000/studyhadoop"); FSDataOutputStream outputStream = fs.create(dfs); outputStream.write(buff,0,buff.length); FileStatus files[] = fs.listStatus( dfs ); for( FileStatus file:files){ System.out.println( "file: " + file.getPath() ); } } catch (Exception e) { e.printStackTrace(); } } }
二:删除HDFS文件
public class Test5DeleteFile { /** * 删除HDFS文件: * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); FileSystem fs = FileSystem.get(uri, conf); Path delef = new Path("hdfs://192.168.226.129:9000/testhadoop1"); boolean isDeleted = fs.delete(delef, false); System.out.println( "isDelete: " + isDeleted ); } catch (Exception e) { e.printStackTrace(); } } }
三:创建HDFS目录
public class Test9Mkdir { /** * HDFS下 创建目录文件 * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); FileSystem fs = FileSystem.get(uri, conf); Path dfs = new Path("hdfs://192.168.226.129:9000/testhadoop"); boolean isMkdirs = fs.mkdirs(dfs); if( isMkdirs ){ System.out.println( " Make Dir Successful ! "); }else{ System.out.println( " Make Dir Failure ! "); } fs.close(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }
四:重命名HDFS文件
public class Test2Rename { /** * 重命名HDFS文件: * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); FileSystem fs = FileSystem.get(uri,conf); Path oldpath = new Path("hdfs://192.168.226.129:9000/testhadoop"); Path newpath = new Path("hdfs://192.168.226.129:9000/testhadoop1"); //判断该文件是否存在 boolean isExists = fs.exists(oldpath); System.out.println( "isExists: " +isExists ); //重命名文件 fs.rename(oldpath, newpath); isExists = fs.exists(newpath); System.out.println( "newpathisExists: " +isExists ); } catch (Exception e) { e.printStackTrace(); } } }
五:上传本地文件至HDFS
public class Test3CopyFile { /** * 上传本地文件到HDFS * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); FileSystem fs = FileSystem.get(uri, conf); Path src = new Path("F:\\04-HadoopStudy\\mapreduce.txt"); Path dst = new Path("hdfs://192.168.226.129:9000/rootdir"); fs.copyFromLocalFile(src, dst); System.out.println("Upload " + conf.get("fs.default.name")); FileStatus files[] = fs.listStatus( dst ); for( FileStatus file:files){ System.out.println( file.getPath() ); } } catch (Exception e) { e.printStackTrace(); } } }
六. 从HDFS下载文件至本地
public class Test10CopyToFile { /** * 从HDFS下载文件至本地 * */ public static void main(String[] args) { try { Configuration conf = new Configuration(); URI uri = new URI("hdfs://192.168.226.129:9000"); FileSystem fs = FileSystem.get(uri, conf); Path src = new Path("F:\\"); Path dst = new Path("hdfs://192.168.226.129:9000/studyhadoop"); fs.copyToLocalFile(dst, src); System.out.println("DownLoad " + conf.get("fs.default.name")); FileStatus files[] = fs.listStatus( dst ); for( FileStatus file:files){ System.out.println( file.getPath() ); } } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }
感谢你能够认真阅读完这篇文章,希望小编分享的“HDFS基本常用命令是什么”这篇文章对大家有帮助,同时也希望大家多多支持创新互联,关注创新互联行业资讯频道,更多相关知识等着你来学习!
名称栏目:HDFS基本常用命令是什么
分享URL:http://ybzwz.com/article/poepdo.html