Java tutorial
/** * Copyright (C) 2010-2016 Gordon Fraser, Andrea Arcuri and EvoSuite * contributors * * This file is part of EvoSuite. * * EvoSuite is free software: you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation, either version 3.0 of the License, or * (at your option) any later version. * * EvoSuite is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>. */ package com.examples.with.different.packagename; /** * <p>Operations on {@link java.lang.String} that are * {@code null} safe.</p> * * <ul> * <li><b>IsEmpty/IsBlank</b> * - checks if a String contains text</li> * <li><b>Trim/Strip</b> * - removes leading and trailing whitespace</li> * <li><b>Equals</b> * - compares two strings null-safe</li> * <li><b>startsWith</b> * - check if a String starts with a prefix null-safe</li> * <li><b>endsWith</b> * - check if a String ends with a suffix null-safe</li> * <li><b>IndexOf/LastIndexOf/Contains</b> * - null-safe index-of checks * <li><b>IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut</b> * - index-of any of a set of Strings</li> * <li><b>ContainsOnly/ContainsNone/ContainsAny</b> * - does String contains only/none/any of these characters</li> * <li><b>Substring/Left/Right/Mid</b> * - null-safe substring extractions</li> * <li><b>SubstringBefore/SubstringAfter/SubstringBetween</b> * - substring extraction relative to other strings</li> * <li><b>Split/Join</b> * - splits a String into an array of substrings and vice versa</li> * <li><b>Remove/Delete</b> * - removes part of a String</li> * <li><b>Replace/Overlay</b> * - Searches a String and replaces one String with another</li> * <li><b>Chomp/Chop</b> * - removes the last part of a String</li> * <li><b>AppendIfMissing</b> * - appends a suffix to the end of the String if not present</li> * <li><b>PrependIfMissing</b> * - prepends a prefix to the start of the String if not present</li> * <li><b>LeftPad/RightPad/Center/Repeat</b> * - pads a String</li> * <li><b>UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize</b> * - changes the case of a String</li> * <li><b>CountMatches</b> * - counts the number of occurrences of one String in another</li> * <li><b>IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable</b> * - checks the characters in a String</li> * <li><b>DefaultString</b> * - protects against a null input String</li> * <li><b>Rotate</b> * - rotate (circular shift) a String</li> * <li><b>Reverse/ReverseDelimited</b> * - reverses a String</li> * <li><b>Abbreviate</b> * - abbreviates a string using ellipsis</li> * <li><b>Difference</b> * - compares Strings and reports on their differences</li> * <li><b>LevenshteinDistance</b> * - the number of changes needed to change one String into another</li> * </ul> * * <p>The {@code StringUtils} class defines certain words related to * String handling.</p> * * <ul> * <li>null - {@code null}</li> * <li>empty - a zero-length string ({@code ""})</li> * <li>space - the space character ({@code ' '}, char 32)</li> * <li>whitespace - the characters defined by {@link Character#isWhitespace(char)}</li> * <li>trim - the characters <= 32 as in {@link String#trim()}</li> * </ul> * * <p>{@code StringUtils} handles {@code null} input Strings quietly. * That is to say that a {@code null} input will return {@code null}. * Where a {@code boolean} or {@code int} is being returned * details vary by method.</p> * * <p>A side effect of the {@code null} handling is that a * {@code NullPointerException} should be considered a bug in * {@code StringUtils}.</p> * * <p>Methods in this class give sample code to explain their operation. * The symbol {@code *} is used to indicate any input including {@code null}.</p> * * <p>#ThreadSafe#</p> * @see java.lang.String * @since 1.0 */ /** * Snippet from Lang project * (org.apache.commons.lang3.StringUtils) */ public class StringUtils { /** * <p>Checks if CharSequence contains a search CharSequence irrespective of case, * handling {@code null}. Case-insensitivity is defined as by * {@link String#equalsIgnoreCase(String)}. * * <p>A {@code null} CharSequence will return {@code false}.</p> * * <pre> * StringUtils.contains(null, *) = false * StringUtils.contains(*, null) = false * StringUtils.contains("", "") = true * StringUtils.contains("abc", "") = true * StringUtils.contains("abc", "a") = true * StringUtils.contains("abc", "z") = false * StringUtils.contains("abc", "A") = true * StringUtils.contains("abc", "Z") = false * </pre> * * @param str the CharSequence to check, may be null * @param searchStr the CharSequence to find, may be null * @return true if the CharSequence contains the search CharSequence irrespective of * case or false if not or {@code null} string input * @since 3.0 Changed signature from containsIgnoreCase(String, String) to containsIgnoreCase(CharSequence, CharSequence) */ public static boolean containsIgnoreCase(final CharSequence str, final CharSequence searchStr) { if (str == null || searchStr == null) { return false; } final int len = searchStr.length(); final int max = str.length() - len; for (int i = 0; i <= max; i++) { if (regionMatches(str, true, i, searchStr, 0, len)) { return true; } } return false; } /** * Green implementation of regionMatches. * * @param cs the {@code CharSequence} to be processed * @param ignoreCase whether or not to be case insensitive * @param thisStart the index to start on the {@code cs} CharSequence * @param substring the {@code CharSequence} to be looked for * @param start the index to start on the {@code substring} CharSequence * @param length character length of the region * @return whether the region matched */ private static boolean regionMatches(final CharSequence cs, final boolean ignoreCase, final int thisStart, final CharSequence substring, final int start, final int length) { return ((String) cs).regionMatches(ignoreCase, thisStart, (String) substring, start, length); } }