Java Decimal decimalAlign(int width, int precision, String s)

Description

Formats a String representation of a decimal number to a stated precision and total width.

License

LGPL

Parameter

Parameter	Description
width	the total number of characters desired in the formatted String
precision	the number of digits to the right of the decimal point in the formatted String
s	the String to be formatted

Return

the formatted String

Declaration

public static String decimalAlign(int width, int precision, String s) 

Method Source Code

//package com.java2s;
//License from project: LGPL 

public class Main {
    /**//from  w  ww  . j a va 2  s  . c om
     * Formats a String representation of a decimal number to a stated precision and total width.  First the
     * substring following the last (right-most) decimal point is right filled with zeroes to the desired
     * precision.  The remainder (most-significant) portion or the original String is then combined with
     * the formatted fraction part and the result is left-filled with space characters to the desired total width.
     * When the original String's only decimal point is the first character in the String, the whole number part
     * will be created as a single '0' character preceeded by whatever space fill is required to achieve the
     * desired total with.
     * @param width the total number of characters desired in the formatted String
     * @param precision the number of digits to the right of the decimal point in the formatted String
     * @param s the String to be formatted
     * @return the formatted String
     */
    public static String decimalAlign(int width, int precision, String s) {
        String fraction = "";
        String whole = "0.";
        int dot = s.lastIndexOf('.');
        if (dot >= 0) {
            whole = s.substring(0, dot + 1);
            fraction = s.substring(dot + 1);
        }

        if (fraction.length() > precision) {
            fraction = fraction.substring(0, precision);
        }
        return fillStart(' ', width, (whole + fillEnd('0', precision, fraction)));
    }

    /**
     * Adds leading characters to a String as required to achieve a specified width.
     * @param c the pad character to use
     * @param width the desired width
     * @param value unformatted String
     * @return a String of the specified length (width)
     */
    public static String fillStart(char c, int width, String value) {
        StringBuffer sb = new StringBuffer().append(value);
        while (sb.length() < width) {
            sb.insert(0, c);
        }
        return sb.toString();
    }

    /**
     * Adds trailing characters to a String as required to achieve a specified width.
     * @param c the pad character to use
     * @param width the desired width
     * @param value unformatted String
     * @return a String of the specified length (width)
     */
    public static String fillEnd(char c, int width, String value) {
        StringBuffer sb = new StringBuffer().append(value);
        while (sb.length() < width) {
            sb.append(c);
        }
        return sb.toString();
    }
}

Related

1. decimalDigit(final long value, final int i)
2. decimalDigitCount(int num)
3. decimalDump(final byte[] bytes)
4. decimalPart(float f)