cn.lhfei.hadoop.ch04.SequenceFileWriteDemo.java Source code

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Here is the source code for cn.lhfei.hadoop.ch04.SequenceFileWriteDemo.java

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/*
 * Copyright 2010-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cn.lhfei.hadoop.ch04;

import java.io.IOException;
import java.net.URI;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.SequenceFile.Writer;
import org.apache.hadoop.io.Text;

/**
 * @version 0.1
 *
 * @author Hefei Li
 *
 * @since Oct 30, 2014
 */

public class SequenceFileWriteDemo {

    private static final String[] DATA = { "One, two, buckle my shoe", "Three, four, shut the door",
            "Five, six, pick up sticks", "Seven, eight, lay them straight", "Nine, ten, a big fat hen" };

    public static void main(String[] args) {

        String uri = args[0];
        Configuration conf = new Configuration();
        FileSystem fs = null;
        SequenceFile.Writer writer = null;

        try {
            fs = FileSystem.get(URI.create(uri), conf);
            Path path = new Path(uri);

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

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

            writer = SequenceFile.createWriter(conf, Writer.keyClass(key.getClass()),
                    writer.valueClass(value.getClass()));

            for (int i = 0; i < 100; i++) {
                key.set(100 - i);
                value.set(DATA[i % DATA.length]);
                System.out.printf("[%s]\t%s\t%s\n", writer.getLength(), key, value);
                writer.append(key, value);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IOUtils.closeStream(writer);
        }

    }

}