hdfs file formats

=NewConfiguration (); Path Local=NewPath (Out_path); out=filesystem.get (CONF). Create (local); File dir=NewFile (Local_path); for(File file:dir.listFiles ()) {Reader=NewInputStreamReader (NewFileInputStream (file),"UTF-8"); Listioutils.readlines (reader); for(String line:readlines) {out.write (Line.getbytes ()); Out.write ("\ n". GetBytes ()); }} System.out.pr

Write more verbose, if you are eager to find the answer directly to see the bold part of the .... (PS: What is written here is all the content in the official document of the 2.5.2, the problem I encountered when I did it) When you execute a mapreduce job locally, you encounter the problem of No such file or directory, follow the steps in the official documentation: 1. Formatting Namenode Bin/hdfs Namen

For HDFS operations, you can use Hadoop FS commands, but also use Java to operate, the following small example, is a brief introduction of the Java Operation HDFs files, etc...Package com.hdfs.nefu;/** * @auther XD **/import java.io.fileinputstream;import java.io.ioexception;import Java.net.uri;import Java.net.urisyntaxexception;import Org.apache.hadoop.conf.configuration;import Org.apache.hadoop.fs.fsdatai

// Create the file core code public static void createnewhdfsfile (string tocreatefilepath, string content) throws ioexception {configuration Config = new configuration (); config. set ("hadoop. job. ugi "," Administrator, supergroup "); filesystem HDFS = filesystem. get (config); fsdataoutputstream OS = HDFS. create (New Path (tocreatefilepath); OS. write (conte

OutputStream=NULL; BooleanFlag =true; Try{ftp.connect (IP); Ftp.login (username, password); Ftp.setfiletype (Ftp.binary_file_type); Ftp.setcontrolencoding ("UTF-8"); intReply =Ftp.getreplycode (); if(!ftpreply.ispositivecompletion (Reply)) {Ftp.disconnect (); } ftpfile[] Files=ftp.listfiles (FilePath); FileSystem HDFs=filesystem.get (conf); for(Ftpfile file:files) {if(! (File.getname (). Equals (".") | | file.getname

1.hdfs File upload mechanismFile Upload process:1. The client wants to Namenode request to upload the file,2.NameNode returns the allocation Datanode for this upload to the client3. The client begins uploading the corresponding block data block to the Dataname.4. After uploading, notify Namenode,namenode to use pipe pipeline mechanism for

Recently, when doing HDFs file processing, I encountered a multi-file join operation, including: All join and the common left JOIN operation, Here is a simple example of using two tables to do a LEFT join where the data structure is as follows: A file: A|1b|2|c B File: A|b|

Recently there is a requirement to calculate the user portrait.The system has about 800W of user volume, calculate some data for each user.The amount of data is relatively large, the use of hive or no pressure, but the written Oracle, in giving the data to the front, it is more uncomfortable.And then a different solution:1.hive calculation, write HDFs2.API read out, write to HBase (HDFs and hbase version mismatch, no way to use Sqoop Direct)And then t

Environment: Win7 Eclipse Hadoop 1.1.2When the file creation is executed, theThatFilesystem.mkdirs (Path);//Want to create a file on Hadoop errorError:Org.apache.hadoop.security.AccessControlException:Permission denied:user=administrator,access=write,inode= "tmp" : Root:supergroup:rwxr-xr-xReason:1. The current user is administrator, not a Hadoop user2. The default HDFs