com.marcolotz.ReducerComponents.ReducedValueWritable.java Source code

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Here is the source code for com.marcolotz.ReducerComponents.ReducedValueWritable.java

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/*******************************************************************************
 * Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International
 * 
 * Copyright (c) 2014 Marco Aurelio Barbosa Fagnani Gomes Lotz (marcolotz.com)
 * 
 * The source code in this document is licensed under Creative Commons
 * Attribution-NonCommercial-ShareAlike 4.0 International License. You must 
 * credit the author of the source code in the way specified by the author or
 * licenser (but not in a way to suggest that the author or licenser has given 
 * you allowance to you or to your use of the source code). If you modify,
 * transform or create using this source code as basis, you can only distribute
 * the new source code under the same license or a similar license to this one.
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * To see a copy of the license, access:
 * creativecommons.org/licenses/by-nc-sa/4.0/legalcode
 ******************************************************************************/
package com.marcolotz.ReducerComponents;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;

import org.apache.hadoop.io.Writable;

import com.marcolotz.MRComponents.SerializerConverter;
import com.marcolotz.MapperComponents.ImageMetadata;

/**
 * In this application one generates a list of MappedValueKeys that will be
 * later serialized into JSON format. The Key Value will be the same for the
 * mapper and for the reducer, since its data should not change if the images
 * are in the same series.
 * 
 * @author Marco Aurelio Lotz
 * 
 */
public class ReducedValueWritable implements Writable {

    private ArrayList<ImageMetadata> reducedList = new ArrayList<ImageMetadata>();

    public ReducedValueWritable() {
    }

    public ReducedValueWritable(ImageMetadata mvs) {
        this.addToReducedList(mvs);
    }

    public ArrayList<ImageMetadata> getReducedList() {
        return this.reducedList;
    }

    public void addToReducedList(ImageMetadata mvs) {
        reducedList.add(mvs);
    }

    @Override
    public void write(DataOutput out) throws IOException {

        /* Serializes the array list */
        // Writes the size of the list
        SerializerConverter.writeInt(reducedList.size(), out);
        // Writes the contents of the list
        for (ImageMetadata imgData : reducedList) {
            imgData.write(out);
        }
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        /*
         * deserializes the array list // reads the size of the list:
         */
        int listSize = SerializerConverter.readInt(in);

        // Allocates a new list:
        this.reducedList = new ArrayList<ImageMetadata>(listSize);

        // populate the list:
        for (int i = 0; i < listSize; i++) {
            ImageMetadata imgData = new ImageMetadata();
            imgData.readFields(in);
            reducedList.add(imgData);
        }
    }
}