Here you can find the source of rightPad(String str, int size, char padChar)
Right pad a String with a specified character.
The String is padded to the size of size .
StringUtils.rightPad(null, *, *) = null StringUtils.rightPad("", 3, 'z') = "zzz" StringUtils.rightPad("bat", 3, 'z') = "bat" StringUtils.rightPad("bat", 5, 'z') = "batzz" StringUtils.rightPad("bat", 1, 'z') = "bat" StringUtils.rightPad("bat", -1, 'z') = "bat"
| Parameter | Description |
|---|---|
| str | the String to pad out, may be null |
| size | the size to pad to |
| padChar | the character to pad with |
private static String rightPad(String str, int size, char padChar)
//package com.java2s; //License from project: Apache License public class Main { /**/* w ww . j ava2s. co m*/ * <p>The maximum size to which the padding constant(s) can expand.</p> */ private static final int PAD_LIMIT = 8192; /** * <p>Right pad a String with a specified character.</p> * <p> * <p>The String is padded to the size of {@code size}.</p> * <p> * <pre> * StringUtils.rightPad(null, *, *) = null * StringUtils.rightPad("", 3, 'z') = "zzz" * StringUtils.rightPad("bat", 3, 'z') = "bat" * StringUtils.rightPad("bat", 5, 'z') = "batzz" * StringUtils.rightPad("bat", 1, 'z') = "bat" * StringUtils.rightPad("bat", -1, 'z') = "bat" * </pre> * * @param str the String to pad out, may be null * @param size the size to pad to * @param padChar the character to pad with * @return right padded String or original String if no padding is necessary, * {@code null} if null String input * @since 2.0 */ private static String rightPad(String str, int size, char padChar) { if (str == null) { return null; } 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(repeat(padChar, pads)); } /** * <p>Right pad a String with a specified String.</p> * <p> * <p>The String is padded to the size of {@code size}.</p> * <p> * <pre> * StringUtils.rightPad(null, *, *) = null * StringUtils.rightPad("", 3, "z") = "zzz" * StringUtils.rightPad("bat", 3, "yz") = "bat" * StringUtils.rightPad("bat", 5, "yz") = "batyz" * StringUtils.rightPad("bat", 8, "yz") = "batyzyzy" * StringUtils.rightPad("bat", 1, "yz") = "bat" * StringUtils.rightPad("bat", -1, "yz") = "bat" * StringUtils.rightPad("bat", 5, null) = "bat " * StringUtils.rightPad("bat", 5, "") = "bat " * </pre> * * @param str the String to pad out, may be null * @param size the size to pad to * @param padStr the String to pad with, null or empty treated as single space * @return right padded String or original String if no padding is necessary, * {@code null} if null String input */ 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)); } } /** * <p>Returns padding using the specified delimiter repeated * to a given length.</p> * <p> * <pre> * StringUtils.repeat(0, 'e') = "" * StringUtils.repeat(3, 'e') = "eee" * StringUtils.repeat(-2, 'e') = "" * </pre> * <p> * <p>Note: this method doesn't not support padding with * <a href="http://www.unicode.org/glossary/#supplementary_character">Unicode Supplementary Characters</a> * as they require a pair of {@code char}s to be represented. * If you are needing to support full I18N of your applications * consider using {@link #repeat(String, int)} instead. * </p> * * @param ch character to repeat * @param repeat number of times to repeat char, negative treated as zero * @return String with repeated character * @see #repeat(String, int) */ private static String repeat(char ch, int repeat) { char[] buf = new char[repeat]; for (int i = repeat - 1; i >= 0; i--) { buf[i] = ch; } return new String(buf); } /** * <p>Checks if a CharSequence is empty ("") or null.</p> * <p> * <pre> * StringUtils.isEmpty(null) = true * StringUtils.isEmpty("") = true * StringUtils.isEmpty(" ") = false * StringUtils.isEmpty("bob") = false * StringUtils.isEmpty(" bob ") = false * </pre> * <p> * <p>NOTE: This method changed in Lang version 2.0. * It no longer trims the CharSequence. * That functionality is available in isBlank().</p> * * @param cs the CharSequence to check, may be null * @return {@code true} if the CharSequence is empty or null * @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence) */ private static boolean isEmpty(CharSequence cs) { return cs == null || cs.length() == 0; } }