edu.cuhk.hccl.hadoop.YelpMapper.java Source code

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Here is the source code for edu.cuhk.hccl.hadoop.YelpMapper.java

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/**
 * Copyright (C) 2014 Pengfei Liu <pfliu@se.cuhk.edu.hk>
 * The Chinese University of Hong Kong.
 *
 * This file is part of aspect-opinion.
 *
 * 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 edu.cuhk.hccl.hadoop;

import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.util.StringUtils;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import edu.cuhk.hccl.YelpApp.Business;
import edu.cuhk.hccl.YelpApp.Review;
import edu.cuhk.hccl.data.DataRecord;
import edu.cuhk.hccl.util.Constant;

public class YelpMapper extends BaseMapper {

    public static final String CATEGORY = "restaurants";
    private static HashSet<String> itemSet = new HashSet<String>();
    private Gson gson = new GsonBuilder().create();

    @Override
    protected void setup(Context context) throws IOException, InterruptedException {
        aspects = Constant.RESTAURANT_ASPECTS;

        try {
            Path[] cacheFiles = DistributedCache.getLocalCacheFiles(context.getConfiguration());
            readItemSet(cacheFiles[0], CATEGORY);
        } catch (IOException ioe) {
            System.err
                    .println("Caught exception while getting cached files: " + StringUtils.stringifyException(ioe));
        }
    }

    @Override
    public DataRecord parseDataRecord(Text value) {
        Review review = gson.fromJson(value.toString(), Review.class);

        if (review.getText().isEmpty() || itemSet.contains(review.getBusinessId())) {

            DataRecord record = new DataRecord();

            record.setUserID(review.getUserID());
            record.setItemID(review.getBusinessID());
            record.setReview(review.getText());
            record.setRating((int) Math.floor(Double.parseDouble(review.getStars())));

            return record;

        } else {
            return null;
        }
    }

    private void readItemSet(Path filePath, String category) {
        if (itemSet.isEmpty()) {
            try {
                List<String> lines = FileUtils.readLines(new File(filePath.toString()), "UTF-8");
                for (String line : lines) {
                    Business business = gson.fromJson(line, Business.class);

                    boolean isIn = false;
                    for (String cate : business.categories) {
                        if (category.equals(cate.toLowerCase())) {
                            isIn = true;
                            break;
                        }
                    }

                    if (isIn) {
                        if (!itemSet.contains(business.business_id)) {
                            itemSet.add(business.business_id);
                        }
                    }
                }

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