de.kp.core.spade.hadoop.ItemsetWritable.java Source code

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Here is the source code for de.kp.core.spade.hadoop.ItemsetWritable.java

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package de.kp.core.spade.hadoop;
/* Copyright (c) 2014 Dr. Krusche & Partner PartG
* 
* This file is part of the Core-SPADE project
* (https://github.com/skrusche63/core-spade).
* 
* Core-SPADE is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
* 
* Core-SPADE is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
* You should have received a copy of the GNU General Public License along with
* Core-SPADE. 
* 
* If not, see <http://www.gnu.org/licenses/>.
*/

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

import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Writable;

import de.kp.core.spade.Item;
import de.kp.core.spade.Itemset;

public class ItemsetWritable implements Writable {

    private LongWritable timestampWritable;
    private ArrayWritable itemlistWritable;

    public ItemsetWritable() {

        timestampWritable = new LongWritable();

        List<ItemWritable> empty = Collections.<ItemWritable>emptyList();
        itemlistWritable = new ArrayWritable(ItemWritable.class, empty.toArray(new Writable[empty.size()]));

    }

    public ItemsetWritable(Itemset itemset) {

        timestampWritable = new LongWritable(itemset.getTimestamp());

        List<Item<?>> items = itemset.getItems();
        ArrayList<ItemWritable> itemWritableList = new ArrayList<ItemWritable>();

        for (int i = 0; i < items.size(); i++) {
            itemWritableList.add(new ItemWritable(items.get(i)));
        }

        this.itemlistWritable = new ArrayWritable(ItemWritable.class,
                itemWritableList.toArray(new Writable[itemWritableList.size()]));

    }

    /* (non-Javadoc)
     * @see org.apache.hadoop.io.Writable#readFields(java.io.DataInput)
     */
    @Override
    public void readFields(DataInput in) throws IOException {
        timestampWritable.readFields(in);
        itemlistWritable.readFields(in);
    }

    /* (non-Javadoc)
     * @see org.apache.hadoop.io.Writable#write(java.io.DataOutput)
     */
    @Override
    public void write(DataOutput out) throws IOException {
        timestampWritable.write(out);
        itemlistWritable.write(out);
    }

    public Itemset get() {

        Itemset itemset = new Itemset();
        itemset.setTimestamp(timestampWritable.get());

        Writable[] writableArray = itemlistWritable.get();
        for (int i = 0; i < writableArray.length; i++) {

            ItemWritable item = (ItemWritable) writableArray[i];
            itemset.addItem(item.get());

        }

        return itemset;

    }

}