org.jpmml.evaluator.CsvUtil.java Source code

Introduction

Here is the source code for org.jpmml.evaluator.CsvUtil.java

Source

/*
 * Copyright (c) 2013 Villu Ruusmann
 *
 * This file is part of JPMML-Evaluator
 *
 * JPMML-Evaluator is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JPMML-Evaluator 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with JPMML-Evaluator.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.jpmml.evaluator;

import java.io.BufferedReader;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

import com.google.common.base.Function;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import org.dmg.pmml.FieldName;

public class CsvUtil {

    private CsvUtil() {
    }

    static public List<Map<FieldName, String>> load(InputStream is) throws IOException {
        List<Map<FieldName, String>> table = Lists.newArrayList();

        BufferedReader reader = new BufferedReader(new InputStreamReader(is, "US-ASCII"));

        try {
            String headerLine = reader.readLine();
            if (headerLine == null) {
                throw new EOFException();
            }

            List<String> headerCells = parseLine(headerLine);

            while (true) {
                String bodyLine = reader.readLine();
                if (bodyLine == null) {
                    break;
                }

                Map<FieldName, String> row = Maps.newLinkedHashMap();

                List<String> bodyCells = parseLine(bodyLine);

                // Must be of equal length
                if (headerCells.size() != bodyCells.size()) {
                    throw new RuntimeException();
                }

                for (int i = 0; i < headerCells.size(); i++) {
                    row.put(FieldName.create(headerCells.get(i)), bodyCells.get(i));
                }

                table.add(row);
            }
        } finally {
            reader.close();
        }

        return table;
    }

    static public List<String> parseLine(String line) {
        List<String> cells = Arrays.asList(line.split(","));

        Function<String, String> function = new Function<String, String>() {

            @Override
            public String apply(String cell) {

                if ("NA".equals(cell) || "N/A".equals(cell)) {
                    return null;
                }

                return cell;
            }
        };

        return Lists.transform(cells, function);
    }
}