Formats a double to produce a string with a number of fraction digits. - Java java.lang

Java examples for java.lang:double Format

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Description

Formats a double to produce a string with a number of fraction digits.

Demo Code

/**/*  w w  w  .  j a v  a  2  s  . c  om*/
 * Copyright (C) 2012 Red Hat, Inc. and/or its affiliates.
 *
 * 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.
 */
//package com.java2s;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

import java.util.Locale;

public class Main {
    /**
     * Formats a double to produce a string with a number of fraction
     * digits.
     *
     * @param origin   double to format
     * @param decimals number of fraction digits
     * @return Formatted string.
     */
    public static String doubleToStr(double origin, int decimals) {
        return getFormat(decimals).format(new Double(origin));
    }

    /**
     * Formats a Number to produce a string with a number of fraction
     * digits.
     *
     * @param origin   Number to format
     * @param decimals number of fraction digits
     * @return Formatted string.
     */
    public static String doubleToStr(Number origin, int decimals) {
        return getFormat(decimals).format(origin);
    }

    /**
     * Returns the decimal formatter, which has a number of decimals.
     *
     * @param decimals number of decimals
     * @return desired DecimalFormat
     */
    private static DecimalFormat getFormat(int decimals) {
        DecimalFormat df;
        df = (DecimalFormat) DecimalFormat.getInstance(Locale.getDefault());
        DecimalFormatSymbols dsym = df.getDecimalFormatSymbols();
        char decimalSeparator = dsym.getDecimalSeparator();

        StringBuffer pattern = new StringBuffer("0");
        pattern.append(decimalSeparator);
        for (int i = 0; i < decimals; i++)
            pattern.append("0");

        DecimalFormat numberFormat = new DecimalFormat(pattern.toString());
        DecimalFormatSymbols decimalSymb;
        decimalSymb = numberFormat.getDecimalFormatSymbols();

        numberFormat.setGroupingSize(50);
        decimalSymb.setDecimalSeparator(decimalSeparator);
        numberFormat.setDecimalFormatSymbols(decimalSymb);

        return numberFormat;
    }
}

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