org.apache.hama.ml.recommendation.cf.InputConverter.java Source code

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Here is the source code for org.apache.hama.ml.recommendation.cf.InputConverter.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hama.ml.recommendation.cf;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.hama.commons.io.VectorWritable;

/**
 * 
 * Helper class to convert input data
 * into OnlineCF compatible format
 * set inputs and parse line by line.
 *
 */
public class InputConverter {
    private String inputPreferences = null;
    private String inputUserFeatures = null;
    private String inputItemFeatures = null;
    private KeyValueParser<Text, VectorWritable> preferencesParser = null;
    private KeyValueParser<Text, VectorWritable> userFeatureParser = null;
    private KeyValueParser<Text, VectorWritable> itemFeatureParser = null;

    /**
     * set preferences input and related parser line by line
     * @param path - path for preferences input data
     * @param parser - line by line parser of input data
     */
    public void setInputPreferences(String path, KeyValueParser<Text, VectorWritable> parser) {
        inputPreferences = path;
        preferencesParser = parser;
    }

    /**
     * set user features input and related parser line by line
     * @param path - path for user features input data
     * @param parser - line by line parser of input data
     */
    public void setInputUserFeatures(String path, KeyValueParser<Text, VectorWritable> parser) {
        inputUserFeatures = path;
        userFeatureParser = parser;
    }

    /**
     * set item features input and related parser line by line
     * @param path - path for item features input data
     * @param parser - line by line parser of input data
     */
    public void setInputItemFeatures(String path, KeyValueParser<Text, VectorWritable> parser) {
        inputItemFeatures = path;
        itemFeatureParser = parser;
    }

    /**
     * converting given inputs into compatible output and save
     * @param outputPath - output path of converted input
     * @return true if success
     */
    public boolean convert(String outputPath) {
        try {
            Configuration conf = new Configuration();
            //URI outputUri = new URI(outputPath);
            Path outputDataPath = new Path(outputPath);
            FileSystem fs = FileSystem.get(conf);
            fs.delete(outputDataPath, true);
            fs.createNewFile(outputDataPath);
            SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, outputDataPath, Text.class,
                    VectorWritable.class);

            // inputPreferences
            writeToFile(inputPreferences, OnlineCF.Settings.DFLT_PREFERENCE_DELIM, preferencesParser, fs, writer);

            // user features
            writeToFile(inputUserFeatures, OnlineCF.Settings.DFLT_USER_DELIM, userFeatureParser, fs, writer);

            // item features
            writeToFile(inputItemFeatures, OnlineCF.Settings.DFLT_ITEM_DELIM, itemFeatureParser, fs, writer);

            writer.close();
            return true;

        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }

    @SuppressWarnings("deprecation")
    /**
     * convert line by line and save
     * @param inputPath - path of file to read
     * @param defaultDelim - delimiter when writing to file as (delim_key, value)
     * @param parser - line by line parser of input data
     * @param fs - file system object
     * @param writer - output file writer
     * @throws IOException
     */
    private void writeToFile(String inputPath, String defaultDelim, KeyValueParser<Text, VectorWritable> parser,
            FileSystem fs, SequenceFile.Writer writer) throws IOException {
        if (inputPath == null || parser == null) {
            return;
        }
        Path path = new Path(inputPath);
        FSDataInputStream preferencesIn = fs.open(path);
        String line = null;
        while ((line = preferencesIn.readLine()) != null) {
            parser.parseLine(line);
            writer.append(new Text(defaultDelim + parser.getKey().toString()), parser.getValue());
        }
    }
}