com.infomata.data.FixedWidthFormat Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of informata-datafile Show documentation

Maven Package for datafile.sourceforge.net Java data file read/write utility that provides a convenient set of interfaces for reading and writing data to and from files in widely accepted format such as comma separated values (CSV), fixed width, tab separated, as well as others.

The newest version!

/*
 * $Id: FixedWidthFormat.java,v 1.2 2005/12/19 12:31:29 oldman1004 Exp $
 *
 * Copyright(c) 2002 Infomata
 * 
 * This library 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.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package com.infomata.data;

import java.util.Iterator;

/**
 * Data file format that uses fixed width to define each item
 * per row of data.
 *
 * @author Sam Kim
 * @version $Revision: 1.2 $
 */
public class FixedWidthFormat implements DataFormat {

    /**
     * Creates a new FixedWidthFormat instance.
     *
     * @param widths list of width of each item contained in
     *               data file in correct order.
     */
    public FixedWidthFormat(int[] widths) {

        beg = new int[widths.length];
        width = new int[widths.length];

        System.arraycopy(widths, 0, width, 0, widths.length);
        System.arraycopy(widths, 0, beg, 1, widths.length - 1);

        if (beg.length > 2) {
            for (int i = 2; i < beg.length; i++) {
                beg[i] += beg[i - 1];
            }
        }
    }

    /**
     * Parses a line of text containing
     * data contained according to pre-defined character widths.
     *
     * @param line String object containing data.
     * @return DataRow object containing data parsed
     *         from line.
     */
    public DataRow parseLine(String line) {

        DataRow row = null;

        if (line != null) {
            row = new DataRow();
            for (int i = 0; i < width.length; i++) {
                if (i == width.length - 1) {
                    row.add(line.substring(beg[i]).trim());
                }
                else {
                    String val = line.substring(beg[i], beg[i + 1]);
                    row.add(val.trim());
                }
            }
        }

        return row;
    }

    /**
     * Formats the data contained in DataRow object
     * into a String according to pre-defined
     * widths.
     *
     * @param row DataRow containing data to be written
     *            to file.
     * @return line of text containing data in specified widths.
     */
    public String format(DataRow row) {

        StringBuffer o = new StringBuffer();
        Iterator i = row.iterator();
        int cnt = 0;

        while (i.hasNext() && cnt < beg.length) {

            String c = (String)i.next();

            int diff = width[cnt] - c.length();

            if (diff > 0) {
                o.append(c);
                for (int j = 0; j < diff; j++) {
                    o.append(SPACE);
                }
            }
            else if (diff < 0) {
                o.append(c.substring(0, width[cnt]));
            }
            else {
                o.append(c);
            }

            cnt++;

        }

        return o.toString();

    }

    private int[] beg = null;
    private int[] width = null;
    private static final char SPACE = ' ';

} // class FixedWidthFormat