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);

        }

 

    }

}