Java tutorial
//package com.java2s; /* * 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. */ public class Main { /** * 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 */ 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; // Extract these first so we detect NPEs the same as the java.lang.String version final int srcLen = cs.length() - thisStart; final int otherLen = substring.length() - start; // Check for invalid parameters if (thisStart < 0 || start < 0 || length < 0) { return false; } // Check that the regions are long enough if (srcLen < length || otherLen < length) { return false; } while (tmpLen-- > 0) { final char c1 = cs.charAt(index1++); final 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; } }