001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.wicket.util.collections; 018 019import java.io.Serializable; 020import java.net.URL; 021import java.util.Comparator; 022 023/** 024 * A comparator of URL instances. 025 * 026 * Comparing URLs with their implementation of #equals() is 027 * bad because it may cause problems like DNS resolving, or other 028 * slow checks. This comparator uses the external form of an URL 029 * to make a simple comparison of two Strings. 030 * 031 * @since 1.5.6 032 */ 033public class UrlExternalFormComparator implements Comparator<URL>, Serializable 034{ 035 private static final long serialVersionUID = 1L; 036 037 @Override 038 public int compare(URL url1, URL url2) 039 { 040 return url1.toExternalForm().compareTo(url2.toExternalForm()); 041 } 042}