/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.codec.binary;
/**
* <p>
* Operations on {@link CharSequence} that are <code>null</code> safe.
* </p>
* <p>
* Copied from Apache Commons Lang r1586295 on April 10, 2014 (day of 3.3.2 release).
* </p>
*
* @see CharSequence
* @since 1.10
*/
public class CharSequenceUtils {
/**
* Green implementation of regionMatches.
*
* @param cs
* the <code>CharSequence</code> to be processed
* @param ignoreCase
* whether or not to be case insensitive
* @param thisStart
* the index to start on the <code>cs</code> CharSequence
* @param substring
* the <code>CharSequence</code> to be looked for
* @param start
* the index to start on the <code>substring</code> CharSequence
* @param length
* character length of the region
* @return whether the region matched
*/
static boolean regionMatches(final CharSequence cs, final boolean ignoreCase, final int thisStart,
final CharSequence substring, final int start, final int length) {
if (cs instanceof String && substring instanceof String) {
return ((String) cs).regionMatches(ignoreCase, thisStart, (String) substring, start, length);
}
int index1 = thisStart;
int index2 = start;
int tmpLen = length;
while (tmpLen-- > 0) {
char c1 = cs.charAt(index1++);
char c2 = substring.charAt(index2++);
if (c1 == c2) {
continue;
}
if (!ignoreCase) {
return false;
}
// The same check as in String.regionMatches():
if (Character.toUpperCase(c1) != Character.toUpperCase(c2) &&
Character.toLowerCase(c1) != Character.toLowerCase(c2)) {
return false;
}
}
return true;
}
}