/*

  * Copyright 1999,2004 The Apache Software Foundation.

  * 

  * Licensed 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.feedparser.network;

 /**

  * This is a portable and thin URL resolver.  The goal is to quickly resolve and

  * normalize URLs.  This includes potentially saving redirects and having them

  * fully qualified.

  * 

  * @author <a href="mailto:burton@openprivacy.org">Kevin A. Burton</a>

  * @version $Id: URLResolver.java 373622 2006-01-30 22:53:00Z mvdb $

  */

 public class URLResolver {

     public static String resolve( String resource ) {

         //include "www" in hostnames like xmlhack.com

         resource = resolveTrailingSlash( resource );

         resource = resolveNoHostname( resource );

         return resource;

     }

     private static String resolveNoHostname( String resource ) {

         if ( resource.startsWith( "http://" ) ) {

             int first = resource.indexOf( "." );

             int second = resource.indexOf( ".", first + 1 );

             if ( second == -1 ) {

                 //then we don't have a hostname on this domain.

                 return resource.substring( 0, "http://".length() ) +

                        "www." + 

                        resource.substring( "http://".length(), resource.length() );

             } 

         }

         return resource;

     }

     private static String resolveTrailingSlash( String resource ) {

         if ( resource.startsWith( "http://" ) && ( resource.endsWith( "org" ) ||

                                                    resource.endsWith( "com" ) ||

                                                    resource.endsWith( "net" ) ) ) {

             return resource + "/";

         } 

         return resource;

     }

 }