Hadoop: Reading and Writing Sequencefile using Apis?

0 votes

Hey, I need to know how to use these functions

 createWriter(Configuration conf, org.apache.hadoop.io.SequenceFile.Writer.Option... opts) 

The Old definition is not working for me:

SequenceFile.createWriter( fs, conf, path, key.getClass(), value.getClass());

Nov 9, 2018 in Big Data Hadoop by slayer
• 29,040 points
17 views

1 answer to this question.

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
0 votes
public class SequenceFilesTest {
  @Test
  public void testSeqFileReadWrite() throws IOException {
    Configuration conf = new Configuration();
    FileSystem fs = FileSystem.getLocal(conf);
    Path seqFilePath = new Path("file.seq");
    SequenceFile.Writer writer = SequenceFile.createWriter(conf,
            Writer.file(seqFilePath), Writer.keyClass(Text.class),
            Writer.valueClass(IntWritable.class));

    writer.append(new Text("key1"), new IntWritable(1));
    writer.append(new Text("key2"), new IntWritable(2));

    writer.close();

    SequenceFile.Reader reader = new SequenceFile.Reader(conf,
            Reader.file(seqFilePath));

    Text key = new Text();
    IntWritable val = new IntWritable();

    while (reader.next(key, val)) {
        System.err.println(key + "\t" + val);
    }

    reader.close();
  }
}
answered Nov 9, 2018 by Omkar
• 65,840 points

Related Questions In Big Data Hadoop

0 votes
1 answer

How to create a FileSystem object that can be used for reading from and writing to HDFS?

Read operation on HDFS In order to read ...READ MORE

answered Mar 21, 2018 in Big Data Hadoop by nitinrawat895
• 9,030 points

edited Mar 21, 2018 by nitinrawat895 144 views
0 votes
1 answer

How to get started with Hadoop and do some development using Eclipse IDE?

Alright, there are couple of things that ...READ MORE

answered Apr 4, 2018 in Big Data Hadoop by Ashish
• 2,630 points
49 views
0 votes
1 answer

IDE for writing and running hadoop jobs?

You can use the Eclipse IDE. It's ...READ MORE

answered Apr 9, 2018 in Big Data Hadoop by kurt_cobain
• 9,260 points
43 views
0 votes
1 answer

How will you choose various file formats for storing and processing data using Apache Hadoop ?

The decision to choose a particular file ...READ MORE

answered Sep 27, 2018 in Big Data Hadoop by zombie
• 3,690 points
50 views
0 votes
1 answer

Hadoop Mapreduce word count Program

Firstly you need to understand the concept ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 9,030 points
1,651 views
0 votes
1 answer

hadoop.mapred vs hadoop.mapreduce?

org.apache.hadoop.mapred is the Old API  org.apache.hadoop.mapreduce is the ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 9,030 points
130 views
0 votes
10 answers

hadoop fs -put command?

copy command can be used to copy files ...READ MORE

answered Dec 7, 2018 in Big Data Hadoop by Sujay
7,990 views
0 votes
1 answer

Hadoop dfs -ls command?

In your case there is no difference ...READ MORE

answered Mar 16, 2018 in Big Data Hadoop by kurt_cobain
• 9,260 points
555 views
0 votes
3 answers

Hadoop hdfs: list all files in a directory and its subdirectories

You can do it using queue: private static ...READ MORE

answered Dec 4, 2018 in Big Data Hadoop by Ishwar
836 views
0 votes
1 answer

Hadoop: How to keep duplicates in Hive using collect_set()?

SELECT hash_id, COLLECT_LIST(num_of_cats) AS ...READ MORE

answered Nov 2, 2018 in Big Data Hadoop by Omkar
• 65,840 points
132 views

© 2018 Brain4ce Education Solutions Pvt. Ltd. All rights Reserved.
"PMP®","PMI®", "PMI-ACP®" and "PMBOK®" are registered marks of the Project Management Institute, Inc. MongoDB®, Mongo and the leaf logo are the registered trademarks of MongoDB, Inc.