hadoop 资料操作

hadoop 文件操作

存储文件：

?import java.io.BufferedInputStream;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

?

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.io.IOUtils;

?

public class AddFile {

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

String localSrc = "E:\\test\\spring3_MVC.docx";

String dst = "hdfs://localhost:9000/home/hdfs/s3.docx";

InputStream in = new BufferedInputStream(new FileInputStream(localSrc));

Configuration conf = new Configuration();

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

OutputStream out = fs.create(new Path(dst), true);

? ? ? ? ? ? ? ? long l1 = System.currentTimeMillis();

IOUtils.copyBytes(in, out, 4096, true);

System.out.println("ms = " + (System.currentTimeMillis() - l1));

}

}

?

?

?

下载文件：

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.io.IOUtils;

?

public class readFile{

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

? ? ? ? String uri = "hdfs://localhost:9000/home/hdfs/s3.docx";

? ? ? ? Configuration conf = new Configuration();

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

? ? ? ? InputStream in = null;

? ? ? ? OutputStream out = null;

? ? ? ? try {

? ? ? ? ? ? in = fs.open(new Path(uri));

? ? ? ? ? ? out = new FileOutputStream("D:/s3.docx");

? ? ? ? ? ? IOUtils.copyBytes(in, out, 4096, false);

? ? ? ? } finally {

? ? ? ? ? ? IOUtils.closeStream(in);

? ? ? ? ? ? IOUtils.closeStream(out);

? ? ? ? }

?

? ? }

}