michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.protocol;
michael@0: 
michael@0: import java.util.HashMap;
michael@0: import java.util.Iterator;
michael@0: import java.util.Map;
michael@0: 
michael@0: /**
michael@0:  * Maintains a map of objects keyed by a request URI pattern.
michael@0:  * <br>
michael@0:  * Patterns may have three formats:
michael@0:  * <ul>
michael@0:  *   <li><code>*</code></li>
michael@0:  *   <li><code>*&lt;uri&gt;</code></li>
michael@0:  *   <li><code>&lt;uri&gt;*</code></li>
michael@0:  * </ul>
michael@0:  * <br>
michael@0:  * This class can be used to resolve an object matching a particular request
michael@0:  * URI.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class UriPatternMatcher {
michael@0: 
michael@0:     /**
michael@0:      * TODO: Replace with ConcurrentHashMap
michael@0:      */
michael@0:     private final Map map;
michael@0: 
michael@0:     public UriPatternMatcher() {
michael@0:         super();
michael@0:         this.map = new HashMap();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Registers the given object for URIs matching the given pattern.
michael@0:      *
michael@0:      * @param pattern the pattern to register the handler for.
michael@0:      * @param obj the object.
michael@0:      */
michael@0:     public synchronized void register(final String pattern, final Object obj) {
michael@0:         if (pattern == null) {
michael@0:             throw new IllegalArgumentException("URI request pattern may not be null");
michael@0:         }
michael@0:         this.map.put(pattern, obj);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Removes registered object, if exists, for the given pattern.
michael@0:      *
michael@0:      * @param pattern the pattern to unregister.
michael@0:      */
michael@0:     public synchronized void unregister(final String pattern) {
michael@0:         if (pattern == null) {
michael@0:             return;
michael@0:         }
michael@0:         this.map.remove(pattern);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @deprecated use {@link #setObjects(Map)}
michael@0:      */
michael@0:     public synchronized void setHandlers(final Map map) {
michael@0:         if (map == null) {
michael@0:             throw new IllegalArgumentException("Map of handlers may not be null");
michael@0:         }
michael@0:         this.map.clear();
michael@0:         this.map.putAll(map);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Sets objects from the given map.
michael@0:      * @param map the map containing objects keyed by their URI patterns.
michael@0:      */
michael@0:     public synchronized void setObjects(final Map map) {
michael@0:         if (map == null) {
michael@0:             throw new IllegalArgumentException("Map of handlers may not be null");
michael@0:         }
michael@0:         this.map.clear();
michael@0:         this.map.putAll(map);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Looks up an object matching the given request URI.
michael@0:      *
michael@0:      * @param requestURI the request URI
michael@0:      * @return object or <code>null</code> if no match is found.
michael@0:      */
michael@0:     public synchronized Object lookup(String requestURI) {
michael@0:         if (requestURI == null) {
michael@0:             throw new IllegalArgumentException("Request URI may not be null");
michael@0:         }
michael@0:         //Strip away the query part part if found
michael@0:         int index = requestURI.indexOf("?");
michael@0:         if (index != -1) {
michael@0:             requestURI = requestURI.substring(0, index);
michael@0:         }
michael@0: 
michael@0:         // direct match?
michael@0:         Object obj = this.map.get(requestURI);
michael@0:         if (obj == null) {
michael@0:             // pattern match?
michael@0:             String bestMatch = null;
michael@0:             for (Iterator it = this.map.keySet().iterator(); it.hasNext();) {
michael@0:                 String pattern = (String) it.next();
michael@0:                 if (matchUriRequestPattern(pattern, requestURI)) {
michael@0:                     // we have a match. is it any better?
michael@0:                     if (bestMatch == null
michael@0:                             || (bestMatch.length() < pattern.length())
michael@0:                             || (bestMatch.length() == pattern.length() && pattern.endsWith("*"))) {
michael@0:                         obj = this.map.get(pattern);
michael@0:                         bestMatch = pattern;
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         return obj;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Tests if the given request URI matches the given pattern.
michael@0:      *
michael@0:      * @param pattern the pattern
michael@0:      * @param requestUri the request URI
michael@0:      * @return <code>true</code> if the request URI matches the pattern,
michael@0:      *   <code>false</code> otherwise.
michael@0:      */
michael@0:     protected boolean matchUriRequestPattern(final String pattern, final String requestUri) {
michael@0:         if (pattern.equals("*")) {
michael@0:             return true;
michael@0:         } else {
michael@0:             return
michael@0:             (pattern.endsWith("*") && requestUri.startsWith(pattern.substring(0, pattern.length() - 1))) ||
michael@0:             (pattern.startsWith("*") && requestUri.endsWith(pattern.substring(1, pattern.length())));
michael@0:         }
michael@0:     }
michael@0: 
michael@0: }