hdfs测试

今天做了一个hdfs测试，就是把文件上传到hdfs

直接放源码吧：

1.mainclass.java

package org.example;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

public class MainClass {

    public static void main(String[] args) throws IOException {
        Configuration conf=new Configuration();
        System.setProperty("HADOOP_USER_NAME", "root");
        conf.set("fs.defaultFS", "hdfs://node1.itcast.cn:8020");
        Path inFile =new Path("y/hdfstest1.txt");
        FileSystem hdfs=FileSystem.get(conf);
        FSDataOutputStream outputStream=hdfs.create(inFile);
        outputStream.writeUTF("信2005-2班20204186叶佳旺HDFS课堂测试");
        outputStream.flush();
        outputStream.close();
    }

}

　　2.read.java

package org.example;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

public class Read {
    public static void main(String[] args) throws IOException {
        Configuration conf=new Configuration();
        System.setProperty("HADOOP_USER_NAME", "root");
        conf.set("fs.defaultFS", "hdfs://node1.itcast.cn:8020");
        Path inFile =new Path("/user/root/y/hdfstest1.txt");
        Path newFile =new Path("/user/root/y/hdfstest2.txt");


        FileSystem hdfs=FileSystem.get(conf);
        FSDataOutputStream outputStream=hdfs.create(newFile);

        FSDataInputStream inputStream=hdfs.open(inFile);
        String str = inputStream.readUTF();
        inputStream.close();

        outputStream.writeUTF(str);
        outputStream.flush();
        outputStream.close();

        inputStream=hdfs.open(newFile);
        System.out.println(inputStream.readUTF());
    }
}