hadoop - Write a file in hdfs with Java

Question

I want to create a file in HDFS and write data in that. I used this code:

Configuration config = new Configuration();     
FileSystem fs = FileSystem.get(config); 
Path filenamePath = new Path("input.txt");  
try {
    if (fs.exists(filenamePath)) {
        fs.delete(filenamePath, true);
    }

    FSDataOutputStream fin = fs.create(filenamePath);
    fin.writeUTF("hello");
    fin.close();
}

It creates the file, but it does't write anything in it. I searched a lot but didn't find anything. What is my problem? Do I need any permission to write in HDFS?

Thanks.

Answer 1

an alternative to @Tariq's asnwer you could pass the URI when getting the filesystem

import org.apache.hadoop.fs.FileSystem
import org.apache.hadoop.conf.Configuration
import java.net.URI
import org.apache.hadoop.fs.Path
import org.apache.hadoop.util.Progressable
import java.io.BufferedWriter
import java.io.OutputStreamWriter

Configuration configuration = new Configuration();
FileSystem hdfs = FileSystem.get( new URI( "hdfs://localhost:54310" ), configuration );
Path file = new Path("hdfs://localhost:54310/s2013/batch/table.html");
if ( hdfs.exists( file )) { hdfs.delete( file, true ); } 
OutputStream os = hdfs.create( file,
    new Progressable() {
        public void progress() {
            out.println("...bytes written: [ "+bytesWritten+" ]");
        } });
BufferedWriter br = new BufferedWriter( new OutputStreamWriter( os, "UTF-8" ) );
br.write("Hello World");
br.close();
hdfs.close();

See example: https://github.com/mpereira-dev/MapReduce-with-Accumulo/blob/master/src/main/java/batch/BatchScan2Html.java