从零开始学习Hadoop-第3章 HDFS分布式文件系统

从零开始学习Hadoop--第3章 HDFS分布式文件系统

packagecom.brianchen.hadoop;

importjava.net.URI;

importorg.apache.hadoop.conf.Configuration;

importorg.apache.hadoop.fs.FileSystem;

importorg.apache.hadoop.fs.FileStatus;

importorg.apache.hadoop.fs.Path;

importorg.apache.hadoop.fs.FileUtil;

public classFileList{

public staticvoid main(String[] args) throws Exception{

if(args.length != 1){

System.err.println("Usage:filelist <source>");

System.exit(2);

}

Configurationconf = new Configuration();

FileSystem fs= FileSystem.get(URI.create(args[0]),conf);

FileStatus[]status = fs.listStatus(new Path(args[0]));

Path[]listedPaths = FileUtil.stat2Paths(status);

for(Path p :listedPaths){

System.out.println(p);

}

}

}

7.3 编译

“cd~/filelist”

“javac-cp /home/brian/usr/hadoop/hadoop-1.2.1/hadoop-core-1.2.1.jar -d./classes ./src/*.java”

7.4 打包

“jar-cvf filelist.jar -C ./classes/ .”

7.5 运行

“cd/home/brian/usr/hadoop/hadoop-1.2.1”

“./bin/hadoopfs -put README.txt readme.txt”

“./bin/hadoopfs -put README.txt readme2.txt”

“./bin/hadoopjar ~/filelist/filelist.jar com.brianchen.hadoop.FileListhdfs://localhost:9000/user/brian”

首先确认Hadoop已经是运行的，然后切换到Hadoop的安装目录，然后列出/user/brian下的文件，有两个，分别是readme.txt和readme2.txt。