Java String Pad Right rightPad(String str, int size, char padChar)

Description

right Pad

License

Open Source License

Declaration

public static String rightPad(String str, int size, char padChar) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    private static final int PAD_LIMIT = 8192;

    public static String rightPad(String str, int size, char padChar) {
        if (str == null) {
            return null;
        }/*from   w  w w  . j a  v a 2 s  . com*/
        int pads = size - str.length();
        if (pads <= 0) {
            return str; // returns original String when possible
        }
        if (pads > PAD_LIMIT) {
            return rightPad(str, size, String.valueOf(padChar));
        }
        return str.concat(padding(pads, padChar));
    }

    public static String rightPad(String str, int size, String padStr) {
        if (str == null) {
            return null;
        }
        if (isEmpty(padStr)) {
            padStr = " ";
        }
        int padLen = padStr.length();
        int strLen = str.length();
        int pads = size - strLen;
        if (pads <= 0) {
            return str; // returns original String when possible
        }
        if (padLen == 1 && pads <= PAD_LIMIT) {
            return rightPad(str, size, padStr.charAt(0));
        }

        if (pads == padLen) {
            return str.concat(padStr);
        } else if (pads < padLen) {
            return str.concat(padStr.substring(0, pads));
        } else {
            char[] padding = new char[pads];
            char[] padChars = padStr.toCharArray();
            for (int i = 0; i < pads; i++) {
                padding[i] = padChars[i % padLen];
            }
            return str.concat(new String(padding));
        }
    }

    private static String padding(int repeat, char padChar) throws IndexOutOfBoundsException {
        if (repeat < 0) {
            throw new IndexOutOfBoundsException("Cannot pad a negative amount: " + repeat);
        }
        final char[] buf = new char[repeat];
        for (int i = 0; i < buf.length; i++) {
            buf[i] = padChar;
        }
        return new String(buf);
    }

    /**
     * Helper function for null and empty string testing.
     *
     * @return true iff s == null or s.equals("");
     */
    public static boolean isEmpty(String s) {
        return makeSafe(s).length() == 0;
    }

    /**
     * Helper function for making null strings safe for comparisons, etc.
     *
     * @return (s == null) ? "" : s;
     */
    public static String makeSafe(String s) {
        return (s == null) ? "" : s;
    }
}

Related

1. rightPad(String str, int size)
2. rightPad(String str, int size)
3. rightPad(String str, int size, char padChar)
4. rightPad(String str, int size, char padChar)
5. rightPad(String str, int size, char padChar)
6. rightPad(String str, int size, String padStr)
7. rightPad(String str, int width)
8. rightPad(String str, int width, char padding)
9. rightPad(String str, String pad, int len)