AJ-Captcha-java

/* *Copyright © 2018 anji-plus *安吉加加信息技术有限公司 *http://www.anji-plus.com *All rights reserved. */ package com.anji.captcha.util; public class StringUtils { /** * The empty String <code>""</code>. * @since 2.0 */ public static final String EMPTY = ""; /** * Represents a failed index search. * @since 2.1 */ public static final int INDEX_NOT_FOUND = -1; /** * <p>The maximum size to which the padding constant(s) can expand.</p> */ private static final int PAD_LIMIT = 8192; /** * <p><code>StringUtils</code> instances should NOT be constructed in * standard programming. Instead, the class should be used as * <code>StringUtils.trim(" foo ");</code>.</p> * * <p>This constructor is public to permit tools that require a JavaBean * instance to operate.</p> */ public StringUtils() { super(); } // Empty checks //----------------------------------------------------------------------- /** * <p>Checks if a String is empty ("") or null.</p> * * <pre> * StringUtils.isEmpty(null) = true * StringUtils.isEmpty("") = true * StringUtils.isEmpty(" ") = false * StringUtils.isEmpty("bob") = false * StringUtils.isEmpty(" bob ") = false * </pre> * * <p>NOTE: This method changed in Lang version 2.0. * It no longer trims the String. * That functionality is available in isBlank().</p> * * @param str the String to check, may be null * @return <code>true</code> if the String is empty or null */ public static boolean isEmpty(String str) { return str == null || str.length() == 0; } /** * <p>Checks if a String is not empty ("") and not null.</p> * * <pre> * StringUtils.isNotEmpty(null) = false * StringUtils.isNotEmpty("") = false * StringUtils.isNotEmpty(" ") = true * StringUtils.isNotEmpty("bob") = true * StringUtils.isNotEmpty(" bob ") = true * </pre> * * @param str the String to check, may be null * @return <code>true</code> if the String is not empty and not null */ public static boolean isNotEmpty(String str) { return !StringUtils.isEmpty(str); } /** * <p>Checks if a String is whitespace, empty ("") or null.</p> * * <pre> * StringUtils.isBlank(null) = true * StringUtils.isBlank("null") = true * StringUtils.isBlank("") = true * StringUtils.isBlank(" ") = true * StringUtils.isBlank("bob") = false * StringUtils.isBlank(" bob ") = false * </pre> * * @param str the String to check, may be null * @return <code>true</code> if the String is null, empty or whitespace * @since 2.0 */ public static boolean isBlank(String str) { int strLen; if (str == null || (strLen = str.length()) == 0) { return true; } if(equals("null", str.trim().toLowerCase())){ return true; } for (int i = 0; i < strLen; i++) { if ((Character.isWhitespace(str.charAt(i)) == false)) { return false; } } return true; } /** * <p>Checks if a String is not empty (""), not null and not whitespace only.</p> * * <pre> * StringUtils.isNotBlank(null) = false * StringUtils.isNotBlank("null") = false * StringUtils.isNotBlank("") = false * StringUtils.isNotBlank(" ") = false * StringUtils.isNotBlank("bob") = true * StringUtils.isNotBlank(" bob ") = true * </pre> * * @param str the String to check, may be null * @return <code>true</code> if the String is * not empty and not null and not whitespace * @since 2.0 */ public static boolean isNotBlank(String str) { return !StringUtils.isBlank(str); } // Trim //----------------------------------------------------------------------- /** * <p>Removes control characters (char &lt;= 32) from both * ends of this String, handling <code>null</code> by returning * an empty String ("").</p> * * <pre> * StringUtils.clean(null) = "" * StringUtils.clean("") = "" * StringUtils.clean("abc") = "abc" * StringUtils.clean(" abc ") = "abc" * StringUtils.clean(" ") = "" * </pre> * * @see java.lang.String#trim() * @param str the String to clean, may be null * @return the trimmed text, never <code>null</code> * @deprecated Use the clearer named {@link #trimToEmpty(String)}. * Method will be removed in Commons Lang 3.0. */ public static String clean(String str) { return str == null ? EMPTY : str.trim(); } /** * <p>Removes control characters (char &lt;= 32) from both * ends of this String, handling <code>null</code> by returning * <code>null</code>.</p> * * <p>The String is trimmed using {@link String#trim()}. * Trim removes start and end characters &lt;= 32. * To strip whitespace use {@link #strip(String)}.</p> * * <p>To trim your choice of characters, use the * {@link #strip(String, String)} methods.</p> * * <pre> * StringUtils.trim(null) = null * StringUtils.trim("") = "" * StringUtils.trim(" ") = "" * StringUtils.trim("abc") = "abc" * StringUtils.trim(" abc ") = "abc" * </pre> * * @param str the String to be trimmed, may be null * @return the trimmed string, <code>null</code> if null String input */ public static String trim(String str) { return str == null ? null : str.trim(); } /** * <p>Removes control characters (char &lt;= 32) from both * ends of this String returning <code>null</code> if the String is * empty ("") after the trim or if it is <code>null</code>. * * <p>The String is trimmed using {@link String#trim()}. * Trim removes start and end characters &lt;= 32. * To strip whitespace use {@link #stripToNull(String)}.</p> * * <pre> * StringUtils.trimToNull(null) = null * StringUtils.trimToNull("") = null * StringUtils.trimToNull(" ") = null * StringUtils.trimToNull("abc") = "abc" * StringUtils.trimToNull(" abc ") = "abc" * </pre> * * @param str the String to be trimmed, may be null * @return the trimmed String, * <code>null</code> if only chars &lt;= 32, empty or null String input * @since 2.0 */ public static String trimToNull(String str) { String ts = trim(str); return isEmpty(ts) ? null : ts; } /** * <p>Removes control characters (char &lt;= 32) from both * ends of this String returning an empty String ("") if the String * is empty ("") after the trim or if it is <code>null</code>. * * <p>The String is trimmed using {@link String#trim()}. * Trim removes start and end characters &lt;= 32. * To strip whitespace use {@link #stripToEmpty(String)}.</p> * * <pre> * StringUtils.trimToEmpty(null) = "" * StringUtils.trimToEmpty("") = "" * StringUtils.trimToEmpty(" ") = "" * StringUtils.trimToEmpty("abc") = "abc" * StringUtils.trimToEmpty(" abc ") = "abc" * </pre> * * @param str the String to be trimmed, may be null * @return the trimmed String, or an empty String if <code>null</code> input * @since 2.0 */ public static String trimToEmpty(String str) { return str == null ? EMPTY : str.trim(); } // Stripping //-----------------------------------------------