001    /*
002     * SonarQube, open source software quality management tool.
003     * Copyright (C) 2008-2014 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * SonarQube is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * SonarQube is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public License
017     * along with this program; if not, write to the Free Software Foundation,
018     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019     */
020    package org.sonar.api.utils;
021    
022    import java.math.BigDecimal;
023    import java.math.RoundingMode;
024    import java.text.NumberFormat;
025    import java.text.ParseException;
026    import java.util.Locale;
027    
028    /**
029     * Utility to parse various inputs
030     *
031     * @since 1.10
032     */
033    public final class ParsingUtils {
034    
035      private ParsingUtils() {
036      }
037    
038      /**
039       * Parses a string with a locale and returns the corresponding number
040       *
041       * @throws ParseException if number cannot be parsed
042       */
043      public static double parseNumber(String number, Locale locale) throws ParseException {
044        if ("".equals(number)) {
045          return Double.NaN;
046        }
047        return NumberFormat.getNumberInstance(locale).parse(number).doubleValue();
048      }
049    
050      /**
051       * Parses a string with the default locale and returns the corresponding number
052       *
053       * @throws ParseException if number cannot be parsed
054       */
055      public static double parseNumber(String number) throws ParseException {
056        return parseNumber(number, Locale.getDefault());
057      }
058    
059      /**
060       * Scales a double value, taking into account 2 decimals
061       */
062      public static double scaleValue(double value) {
063        return scaleValue(value, 2);
064      }
065    
066      /**
067       * Scales a double value with decimals
068       */
069      public static double scaleValue(double value, int decimals) {
070        BigDecimal bd = BigDecimal.valueOf(value);
071        return bd.setScale(decimals, RoundingMode.HALF_UP).doubleValue();
072      }
073    
074    }