com.marcolotz.MRComponents.SerializerConverter.java Source code

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Here is the source code for com.marcolotz.MRComponents.SerializerConverter.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.MRComponents;

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

import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;

/**
 * This class converts the original java structure into Hadoop Writable
 * structures and then handles its serializations and deserializatons.
 * 
 * @author Marco Aurelio Lotz
 * 
 */
public class SerializerConverter {

    /***
     * This is a refactored manner to serialize a String. Basically it transform
     * it into a Text and then writes it in the DataOutput.
     * 
     * @param outputString
     * @param out
     * @throws IOException
     */
    public static void writeString(String outputString, DataOutput out) throws IOException {
        Text writtenString;

        /* Prevents a null string exception when writting it to the output */
        if (outputString == null) {
            writtenString = new Text("null");
        } else {
            writtenString = new Text(outputString);
        }
        writtenString.write(out);
    }

    /***
     * This is a refactored manner to deserialize a String. Basically it creates
     * a new Text, reads the field and then return the new String;
     * 
     * @param dataInput
     * @return the string that was readen
     * @throws IOException
     */
    public static String readString(DataInput dataInput) throws IOException {
        Text readenString = new Text();
        readenString.readFields(dataInput);
        return readenString.toString();
    }

    /***
     * Writes a double to the output.
     * @param outputDouble
     * @param out
     * @throws IOException
     */
    public static void writeDouble(double outputDouble, DataOutput out) throws IOException {
        DoubleWritable writtenDouble = new DoubleWritable(outputDouble);
        writtenDouble.write(out);
    }

    /***
     * Reads a double from the input
     * @param datainput
     * @return the double readen
     * @throws IOException
     */
    public static double readDouble(DataInput datainput) throws IOException {
        DoubleWritable readenDouble = new DoubleWritable();
        readenDouble.readFields(datainput);
        return readenDouble.get();
    }

    /**
     * Writes an int to the output.
     * @param outputInt
     * @param out
     * @throws IOException
     */
    public static void writeInt(int outputInt, DataOutput out) throws IOException {
        IntWritable writtenInt = new IntWritable(outputInt);
        writtenInt.write(out);
    }

    /***
     * Reads an Int from the input
     * @param datainput
     * @return the int readen
     * @throws IOException
     */
    public static int readInt(DataInput datainput) throws IOException {
        IntWritable readenInt = new IntWritable();
        readenInt.readFields(datainput);
        return readenInt.get();
    }

}