ch.sdi.core.impl.parser.CsvParser.java Source code

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Here is the source code for ch.sdi.core.impl.parser.CsvParser.java

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/**
 * Copyright (c) 2014 by the original author or authors.
 *
 * This code is free software; you can redistribute it and/or modify it under the terms of the
 * GNU Lesser General Public License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package ch.sdi.core.impl.parser;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Scanner;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import ch.sdi.core.exc.SdiException;
import ch.sdi.core.impl.data.filter.RawDataFilterString;
import ch.sdi.report.ReportMsg;

/**
 * A Parser for CSV files.
 *
 * @version 1.0 (01.11.2014)
 * @author  Heri
 */
@Component
public class CsvParser {

    /** logger for this class */
    private Logger myLog = LogManager.getLogger(CsvParser.class);

    /**
     * Parses the given input stream.
     * <p>
     *
     * @param aInputStream
     *        must not be null
     * @param aDelimiter
     *        must not be null
     * @param aEncoding
     *        The encoding to be used. If null or empty, the systems default encoding is used.
     * @return a list which contains a list for each found person. The inner list contains the found
     *         values for this person. The number and the order must correspond to the configured field
     *         name list (see
     *         in each line.
     * @throws SdiException
     */
    public List<List<String>> parse(InputStream aInputStream, String aDelimiter, String aEncoding)
            throws SdiException {
        return parse(aInputStream, aDelimiter, aEncoding, null);
    }

    /**
     * Parses the given input stream.
     * <p>
     *
     * @param aInputStream
     *        must not be null
     * @param aDelimiter
     *        must not be null
     * @param aEncoding
     *        The encoding to be used. If null or empty, the systems default encoding is used.
     * @return a list which contains a list for each found person. The inner list contains the found
     *         values for this person. The number and the order must correspond to the configured field
     *         name list (see
     *         in each line.
     * @throws SdiException
     */
    public List<List<String>> parse(InputStream aInputStream, String aDelimiter, String aEncoding,
            List<RawDataFilterString> aFilters) throws SdiException {
        if (!StringUtils.hasLength(aDelimiter)) {
            throw new SdiException("Delimiter not set", SdiException.EXIT_CODE_CONFIG_ERROR);
        } // if myDelimiter == null

        try {
            myLog.debug("Using encoding " + aEncoding);

            BufferedReader br = new BufferedReader(
                    !StringUtils.hasText(aEncoding) ? new InputStreamReader(aInputStream)
                            : new InputStreamReader(aInputStream, aEncoding));
            List<List<String>> result = new ArrayList<>();
            Collection<String> myLinesFiltered = new ArrayList<>();

            int lineNo = 0;
            String line;
            LineLoop: while ((line = br.readLine()) != null) {
                lineNo++;

                if (aFilters != null) {
                    for (RawDataFilterString filter : aFilters) {
                        if (filter.isFiltered(line)) {
                            myLog.debug("Skipping commented line: " + line);
                            myLinesFiltered.add(line);
                            continue LineLoop;
                        }
                    }
                }

                myLog.debug("Parsing line " + lineNo + ": " + line);

                List<String> list = new ArrayList<String>();
                Scanner sc = new Scanner(line);
                try {
                    sc.useDelimiter(aDelimiter);
                    while (sc.hasNext()) {
                        list.add(sc.next());
                    }

                    // Note: if the line is terminated by the delimiter (last entry not present, the last entry
                    // will not appear in the scanned enumeration. Check for this special case:
                    if (line.endsWith(aDelimiter)) {
                        list.add("");
                    } // if line.endsWith( aDelimiter )
                } finally {
                    sc.close();
                }

                result.add(list);
            }

            myLog.info(new ReportMsg(ReportMsg.ReportType.PREPARSE_FILTER, "Filtered lines", myLinesFiltered));

            return result;
        } catch (Throwable t) {
            throw new SdiException("Problems while parsing CSV file", t, SdiException.EXIT_CODE_PARSE_ERROR);
        }
    }

}