Java Fraction Format format(double number, int digits)

Description

Use this method like this:
String formatted = Util.format(1234.67789, 2);
formatted ==> "1234.68"

License

Apache License

Parameter

Parameter	Description

Return

formatted double

Declaration

public static double format(double number, int digits) 

Method Source Code

//package com.java2s;
/**/*  www.  j  a v a 2  s. c om*/
 * Copyright 2014 tgrape Inc.
 * 
 * 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;

public class Main {
    /**
    * relation fuction to Currency format<br>
    * <font color="#0000ff">String formatted = Util.format("1234.67789", 2);<br>
    * formatted ==> "1234.68"
    * </font>
    * @param String<br>
    * @param int<br>
    * @return formatted double
    */
    public static double format(String str_number, int digits) {
        String pattern = "###.";
        double value = -1.;
        for (int i = 0; i < digits; i++) {
            pattern += "#";
        }
        try {
            value = Double.parseDouble(str_number);
        } catch (NumberFormatException e) {
            System.err.println("[Util] Bad Number String!!");
        }
        return customFormat(pattern, value);
    }

    /**
    * Use this method like this:<br>
    * <font color="#0000ff">String formatted = Util.format(1234.67789, 2);<br>
    * formatted ==> "1234.68"
    * </font>
    * @param numer<br>
    * @param digits<br>
    * @return formatted double
    */
    public static double format(double number, int digits) {
        return format("" + number, digits);
    }

    /**
    * This method actually does all for number formatting...<br>
    * @param pattern pattern to apply to the given double value<br>
    * @param value number to be formatted<br>
    * @return formatted double
    */
    private static double customFormat(String pattern, double value) {
        DecimalFormat myFormatter = new DecimalFormat(pattern);
        try {
            String output = myFormatter.format(value);
            return Double.parseDouble(output);
        } catch (NumberFormatException e) {
            System.err.println("[Util] at customFormat(..): NumberFormatException");
            return -1.0;
        }
    }
}

Related

1. format(double num, int n)
2. format(double num, String pattern)
3. format(double number)
4. format(double number)
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7. format(double price)
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