001 /* 002 * Copyright 1999,2004 The Apache Software Foundation. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017 package org.apache.commons.feedparser.network; 018 019 020 /** 021 * This is a portable and thin URL resolver. The goal is to quickly resolve and 022 * normalize URLs. This includes potentially saving redirects and having them 023 * fully qualified. 024 * 025 * @author <a href="mailto:burton@openprivacy.org">Kevin A. Burton</a> 026 * @version $Id: URLResolver.java 373622 2006-01-30 22:53:00Z mvdb $ 027 */ 028 public class URLResolver { 029 030 public static String resolve( String resource ) { 031 032 //include "www" in hostnames like xmlhack.com 033 resource = resolveTrailingSlash( resource ); 034 resource = resolveNoHostname( resource ); 035 036 return resource; 037 038 } 039 040 private static String resolveNoHostname( String resource ) { 041 042 if ( resource.startsWith( "http://" ) ) { 043 044 int first = resource.indexOf( "." ); 045 int second = resource.indexOf( ".", first + 1 ); 046 047 if ( second == -1 ) { 048 //then we don't have a hostname on this domain. 049 return resource.substring( 0, "http://".length() ) + 050 "www." + 051 resource.substring( "http://".length(), resource.length() ); 052 } 053 054 } 055 056 return resource; 057 058 } 059 060 private static String resolveTrailingSlash( String resource ) { 061 062 if ( resource.startsWith( "http://" ) && ( resource.endsWith( "org" ) || 063 resource.endsWith( "com" ) || 064 resource.endsWith( "net" ) ) ) { 065 066 return resource + "/"; 067 068 } 069 070 return resource; 071 072 } 073 074 }