GrepColumnMapper.java

package org.openflamingo.mapreduce.etl.grep;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.openflamingo.mapreduce.core.Delimiter;
import org.openflamingo.mapreduce.parser.CsvRowParser;
import org.openflamingo.mapreduce.util.ArrayUtils;
import org.openflamingo.mapreduce.util.CounterUtils;
import org.openflamingo.mapreduce.util.StringUtils;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 정규 표현식을 이용하여 로우를 Grep하는 Grep ETL 매퍼
 *
 * @author Edward KIM
 * @author Seo Ji Hye
 * @since 0.1
 */
public class GrepColumnMapper extends Mapper<LongWritable, Text, NullWritable, Text> {

	/**
	 * 입력 Row를 컬럼으로 구분하기 위해서 사용하는 컬럼간 구분자
	 */
	private String inputDelimiter;

	/**
	 * 출력 Row를 구성하기 위해서 사용하는 컬럼간 구분자
	 */
	private String outputDelimiter;

	/**
	 * Grep할 컬럼들의 인덱스 배열
	 */
	private Integer[] columnsToGrep;

	/**
	 * Row의 컬럼 개수
	 */
	private int columnSize;

	/**
	 * CSV Row Parser
	 */
	private CsvRowParser parser;

	/**
	 * 정규 표현식
	 */
	private String[] regEx;

	/**
	 * 정규 표현식 패턴
	 */
	private Pattern pattern;

	@Override
	protected void setup(Context context) throws IOException, InterruptedException {
		Configuration configuration = context.getConfiguration();
		inputDelimiter = configuration.get("inputDelimiter", Delimiter.COMMA.getDelimiter());
		outputDelimiter = configuration.get("outputDelimiter", Delimiter.COMMA.getDelimiter());

		columnSize = configuration.getInt("columnSize", -1);
		if (columnSize == -1) {
			throw new IllegalArgumentException("You must specify 'columnSize' for validating the column size.");
		}

		regEx = StringUtils.commaDelimitedListToStringArray(configuration.get("regEx"));

		String[] stringArrayColumns = StringUtils.commaDelimitedListToStringArray(configuration.get("columnsToGrep"));
		if (stringArrayColumns.length == 0) {
			throw new IllegalArgumentException("You must specify 'columnsToFilter' for cleaning some columns.");
		}

		columnsToGrep = ArrayUtils.toIntegerArray(stringArrayColumns);

		if (regEx.length != columnsToGrep.length) {
			throw new IllegalArgumentException("Invalid Parameter Length");
		}

		parser = new CsvRowParser(columnSize, inputDelimiter, outputDelimiter);
	}

	@Override
	protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
		parser.parse(value.toString());

		int i = 0;
		int count = 0;
		while (i < columnsToGrep.length) {
			pattern = Pattern.compile(regEx[i]);
			Matcher matcher = pattern.matcher(parser.get(columnsToGrep[i]));
			// columns들이 모두 match 되었는지 검사
			if (matcher.find()) {
				count++;
			}
			i++;
		}

		if (count == columnsToGrep.length) {
			CounterUtils.writerMapperCounter(this, "YES", context);
			context.write(NullWritable.get(), new Text(value));
		} else {
			CounterUtils.writerMapperCounter(this, "NO", context);
		}
	}
}