hadoop学习1 java操作HDFS

1、创建目录

package hdfs.operation;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.Path;

public class MakeDir {

public static void main(String[] args) throws IOException {

Configuration conf = new Configuration();

conf.set("fs.defaultFS", "hdfs://192.168.86.133:9000"); // master

FileSystem fs = FileSystem.get(conf);

Path path = new Path("/user/hadoop/");

fs.mkdirs(path);

fs.close();

System.out.println("end");

}

}

2、创建文件

fs.create(path);

3、读取文件

package hdfs.operation;

import java.io.IOException;

import java.net.URI;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.FSDataInputStream;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.Path;

public class FileReadFromHdfs {

public static void main(String[] args) {

try {

String dsf = "/user/hadoop/write.txt";

Configuration conf = new Configuration();

conf.set("fs.defaultFS", "hdfs://192.168.86.133:9000"); // master

FileSystem fs = FileSystem.get(URI.create(dsf), conf);

FSDataInputStream hdfsInStream = fs.open(new Path(dsf));

byte[] ioBuffer = new byte[1024];

int readLen = hdfsInStream.read(ioBuffer);

while (readLen != -1) {

System.out.write(ioBuffer, 0, readLen);

readLen = hdfsInStream.read(ioBuffer);

}

hdfsInStream.close();

fs.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

等等