Java Scanner Usage getNextLine(final Scanner source)

Description

Read lines from input java.util.Scanner until it finds a non-commented line, then send it back.

License

Open Source License

Parameter

Parameter	Description
source	The scanner to read lines from.

Return

The first non-commented line found, or null if scanner is empty or contains only comments.

Declaration

static String getNextLine(final Scanner source)

Method Source Code

//package com.java2s;
/*//from  w w w. j  a v a2  s .  com
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2010-2015, Geomatys
 *
 *    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;
 *    version 2.1 of the License.
 *
 *    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.
 */

import java.util.Scanner;

public class Main {
    public static final String COMMENT_STRING = "#";

    /**
     * Read lines from input {@link java.util.Scanner} until it finds a non-commented line, then send it back.
     * @param source The scanner to read lines from.
     * @return The first non-commented line found, or null if scanner is empty or contains only comments.
     */
    static String getNextLine(final Scanner source) {
        String line;
        while (source.hasNextLine()) {
            line = source.nextLine();
            if (line.startsWith(COMMENT_STRING)) {
                continue;
            } else {
                final int commentIndex = line.indexOf(COMMENT_STRING);
                if (commentIndex < 0) {
                    return line;
                } else {
                    return line.substring(0, commentIndex);
                }
            }
        }
        return null;
    }
}