1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.codec.binary; 18 19 /** 20 * <p> 21 * Operations on {@link CharSequence} that are <code>null</code> safe. 22 * </p> 23 * <p> 24 * Copied from Apache Commons Lang r1586295 on April 10, 2014 (day of 3.3.2 release). 25 * </p> 26 * 27 * @see CharSequence 28 * @since 1.10 29 */ 30 public class CharSequenceUtils { 31 32 /** 33 * Green implementation of regionMatches. 34 * 35 * @param cs 36 * the <code>CharSequence</code> to be processed 37 * @param ignoreCase 38 * whether or not to be case insensitive 39 * @param thisStart 40 * the index to start on the <code>cs</code> CharSequence 41 * @param substring 42 * the <code>CharSequence</code> to be looked for 43 * @param start 44 * the index to start on the <code>substring</code> CharSequence 45 * @param length 46 * character length of the region 47 * @return whether the region matched 48 */ 49 static boolean regionMatches(final CharSequence cs, final boolean ignoreCase, final int thisStart, 50 final CharSequence substring, final int start, final int length) { 51 if (cs instanceof String && substring instanceof String) { 52 return ((String) cs).regionMatches(ignoreCase, thisStart, (String) substring, start, length); 53 } 54 int index1 = thisStart; 55 int index2 = start; 56 int tmpLen = length; 57 58 while (tmpLen-- > 0) { 59 char c1 = cs.charAt(index1++); 60 char c2 = substring.charAt(index2++); 61 62 if (c1 == c2) { 63 continue; 64 } 65 66 if (!ignoreCase) { 67 return false; 68 } 69 70 // The same check as in String.regionMatches(): 71 if (Character.toUpperCase(c1) != Character.toUpperCase(c2) && 72 Character.toLowerCase(c1) != Character.toLowerCase(c2)) { 73 return false; 74 } 75 } 76 77 return true; 78 } 79 }