Hadoop: Reading and Writing Sequencefile using Apis?

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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
• 29,170 points
33 views

1 answer to this question.

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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
• 67,660 points

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