An example for HFileInputFormat

HFileInputFormatDemo.java

package com.woodywang;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;

public class App {
    private static class HFileMapper extends Mapper<ImmutableBytesWritable, KeyValue, Text, Text> {

		public void map(ImmutableBytesWritable key, KeyValue keyValue, Context context) throws IOException, InterruptedException {
			Text row = new Text(key.get());
			String column = Bytes.toString(keyValue.getQualifier());
			String value = Bytes.toString(keyValue.getValue());
			Text outputValue = new Text(column + ": " + value);
			context.write(row, outputValue);
		}
	}

	public static void main(String[] args) throws Exception {
		String path = "/Users/woody/hfile";
		Job job = new Job();
		job.setMapperClass(HFileMapper.class);
		job.setMapOutputKeyClass(Text.class);
		job.setMapOutputValueClass(Text.class);
		job.setNumReduceTasks(0);
		job.setInputFormatClass(HFileInputFormat.class);
		FileInputFormat.addInputPath(job, new Path(path));
		FileOutputFormat.setOutputPath(job, new Path("/tmp/hfile"));

		job.waitForCompletion(true);
	}
}