Use apache hadoop file system - Java Big Data

Java examples for Big Data:Hadoop

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Description

Use apache hadoop file system

Demo Code


import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
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.FSDataOutputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;

public class FileSystemTest {
    public static void main(String[] args) throws Exception {
        System.setProperty("HADOOP_USER_NAME", "root");
        System.setProperty("HADOOP_USER_PASSWORD", "neusoft");
        FileSystem fileSystem = FileSystem.newInstance(new URI(
                "hdfs://neusoft-master:9000"), new Configuration());
        fileSystem.delete(new Path("/a.jpg"), false);
    }//from   w w w .  ja v a2s  .  c  o m

    private static void show(FileSystem fileSystem) throws IOException,
            FileNotFoundException {
        FSDataInputStream in = fileSystem.open(new Path(
                "/test.jpg"));
        IOUtils.copyBytes(
                in,
                new FileOutputStream(
                        "C:\\Users\\test\\Desktop\\___test.jpg"),
                1024, true);
    }

    private static void put(FileSystem fileSystem) throws IOException,
            FileNotFoundException {
        FSDataOutputStream out = fileSystem.create(new Path(
                "/test.jpg"));
        IOUtils.copyBytes(
                new FileInputStream(
                        "C:\\Users\\test\\Desktop\\test.jpg"),
                out, 1024, true);
    }

    private static void ls(FileSystem fileSystem) throws Exception {
        FileStatus[] listStatus = fileSystem.listStatus(new Path("/"));
        for (FileStatus fileStatus : listStatus) {
            System.out.println(fileStatus);
        }
    }
}

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