Hadoop learning-seek relocation stream-day04

Import java.io.ByteArrayOutputStream

Import java.io.FileInputStream

Import java.io.FileOutputStream

Import java.io.InputStream

Import java.net.URL

Import org.apache.hadoop.conf.Configuration

Import org.apache.hadoop.fs.FSDataInputStream

Import org.apache.hadoop.fs.FSDataOutputStream

Import org.apache.hadoop.fs.FileSystem

Import org.apache.hadoop.fs.FsUrlStreamHandlerFactory

Import org.apache.hadoop.fs.Path

Import org.apache.hadoop.io.IOUtils

Import org.junit.Test

Public class seek {

/ * *

* seek operation through API

*

* @ author Administrator

*

* [hadoop@hadoop01 ~] $hdfs dfs-chmod-R aquiw / user/hadoop

* [hadoop@hadoop01 ~] $hdfs dfs-ls-R /

*

*

, /

@ Test

Public void seekfile () throws Exception {

/ / create configuration objects, which have a default loading order, first from core-default.xml to the files in the src directory, here

/ / We have given

Configuration conf = new Configuration ()

/ / the distributed file system fs is created through the configuration object of conf. By default, it is the local file system if no file is specified.

FileSystem fs = FileSystem.get (conf)

/ / define a string of URL

String file = "hdfs://hadoop01:9000/user/hadoop/data2/kaola.jpg"

/ / construct a path object from a string of URL

Path path = new Path (file)

FSDataInputStream in = fs.open (path)

/ / streaming copy

IOUtils.copyBytes (in, new FileOutputStream ("E:/kaola1.jpg"), 1024, false)

/ / relocate to the starting point of the file. Only FSDataInputStream implements the seek interface, but FSDataOutputStream does not.

In.seek (0)

IOUtils.copyBytes (in, new FileOutputStream ("E:/kaola2.jpg"), 1024, true)

}

}