Java BigDecimal Round roundDecimals(Float d)

Description

Round a float to decimal

License

Open Source License

Parameter

Parameter	Description
d	a parameter

Return

rounded to one decimal

Declaration

public static Float roundDecimals(Float d) 

Method Source Code

//package com.java2s;
/*/* www .ja  va  2 s  . c o m*/
#
# Copyright (C) 2010-2011 Anders H??l, Ingenjorsbyn AB
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
 */

import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

public class Main {
    private static Map<String, DecimalFormat> decFormatMapCache = new HashMap<String, DecimalFormat>();
    private final static DecimalFormatSymbols DECIMALSEP = new DecimalFormatSymbols(new Locale("us_US"));

    /**
     * Round a float to decimal
     * 
     * @param d
     * @return rounded to one decimal
     */
    public static Float roundDecimals(Float d) {
        Float roundedFloat = null;
        if (d != null) {
            int nrdec = getNumberOfDecimalPlace(d);
            StringBuilder strbuf = new StringBuilder();
            strbuf.append("#.");
            for (int i = 0; i < nrdec; i++) {
                strbuf.append("#");
            }

            DecimalFormat decformatter = decFormatMapCache.get(strbuf.toString());

            if (decformatter == null) {
                decformatter = new DecimalFormat(strbuf.toString(), DECIMALSEP);
                decFormatMapCache.put(strbuf.toString(), decformatter);
            }

            roundedFloat = Float.valueOf(decformatter.format(d));
        }

        return roundedFloat;
    }

    private static int getNumberOfDecimalPlace(double value) {
        final BigDecimal bigDecimal = new BigDecimal("" + value);
        final String s = bigDecimal.toPlainString();
        final int index = s.indexOf('.');
        if (index < 0) {
            return 0;
        }
        return s.length() - 1 - index;
    }
}

Related

1. round_BigDecimal(double d, int decLen)
2. roundBigDecimal(BigDecimal num)
3. roundBigDecimal(Number value, double precision)
4. roundCommercial(BigDecimal value, int decimalPlaces)
5. roundDecimal(Object value)
6. roundDoubleAsBigDecimal(double d, int numberOfDecimals)
7. roundDown(BigDecimal a)
8. rounded(BigDecimal amount)
9. roundHalfUp2Scale(BigDecimal value)