Android String Format formatNumberWithTwoDecimals(Locale locale, String stringToFormat)

Description

Format String like a number with two decimals WARNING: Only use this method to present data to the screen

License

Apache License

Parameter

Parameter	Description
locale	Locale
stringToFormat	String to format

Return

a formatted as a number with two decimals assuming the receiver is a float string read from XML

Declaration

public static String formatNumberWithTwoDecimals(Locale locale,
        String stringToFormat)

Method Source Code

//package com.java2s;
/*//  w w w.  j a va 2s .co  m
 * (C) Copyright Itude Mobile B.V., The Netherlands
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

import java.util.Locale;

public class Main {
    /**
     * Format {@link String} like a number with two decimals
     * 
     * WARNING: Only use this method to present data to the screen
     * 
     * @param locale {@link Locale}
     * @param stringToFormat {@link String} to format
     * @return a {@link String} formatted as a number with two decimals assuming the receiver is a float string read from XML
     */
    public static String formatNumberWithTwoDecimals(Locale locale,
            String stringToFormat) {
        return formatNumberWithDecimals(locale, stringToFormat, 2);
    }

    /***
     * Format {@link String} like a number with given decimals
     * 
     * @param stringToFormat {@link String} to format
     * @param exactNumberOfDecimals can be any number, also negative as the used DecimalFormatter accepts it and makes it 0
     * @return a {@link String} formatted as a number with given decimals assuming the receiver is a float string read from XML
     */
    public static String formatNumberWithDecimals(Locale locale,
            String stringToFormat, int exactNumberOfDecimals) {
        return formatNumberWithDecimals(locale, stringToFormat,
                exactNumberOfDecimals, exactNumberOfDecimals);
    }

    /**
     * 
     * Format {@link String} like a number with given decimals
     * 
     * @param locale {@link Locale}
     * @param stringToFormat {@link String} to format
     * @param minimalNumberOfDecimals minimal amount of decimals. Can be any number, also negative as the used DecimalFormatter 
     * @param maximumNumberOfDecimals maximum amount of decimals. Can be any number, also negative as the used DecimalFormatter 
     * @return a {@link String} formatted as a number with given decimals assuming the receiver is a float string read from XML
     */
    public static String formatNumberWithDecimals(Locale locale,
            String stringToFormat, int minimalNumberOfDecimals,
            int maximumNumberOfDecimals) {
        if (stringToFormat == null || stringToFormat.length() == 0) {
            return null;
        }

        String result = null;

        DecimalFormat formatter = new DecimalFormat();
        setupFormatter(formatter, locale, minimalNumberOfDecimals,
                maximumNumberOfDecimals);

        result = formatter.format(Double.parseDouble(stringToFormat));

        return result;
    }

    /**
     * Set the formatter.
     * 
     * @param formatter {@link DecimalFormat}
     * @param locale {@link Locale}
     * @param numDec number of decimals
     */
    private static void setupFormatter(DecimalFormat formatter,
            Locale locale, int numDec) {
        setupFormatter(formatter, locale, numDec, numDec);
    }

    /**
     * Set the formatter.
     * 
     * @param formatter {@link DecimalFormat}
     * @param locale {@link Locale}
     * @param minimalDecimalNumbers minimal number of decimals
     * @param maximumDecimalNumbers maximum number of decimals
     */
    private static void setupFormatter(DecimalFormat formatter,
            Locale locale, int minimalDecimalNumbers,
            int maximumDecimalNumbers) {
        formatter.setDecimalFormatSymbols(new DecimalFormatSymbols(locale));
        formatter.setMinimumIntegerDigits(1);
        formatter.setMinimumFractionDigits(minimalDecimalNumbers);
        formatter.setMaximumFractionDigits(maximumDecimalNumbers);
        formatter.setGroupingUsed(true);
        formatter.setGroupingSize(3);
    }
}