1 /* 2 * ==================================================================== 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * ==================================================================== 20 * 21 * This software consists of voluntary contributions made by many 22 * individuals on behalf of the Apache Software Foundation. For more 23 * information on the Apache Software Foundation, please see 24 * <http://www.apache.org/>. 25 * 26 */ 27 28 package org.apache.hc.core5.http.protocol; 29 30 import java.util.HashSet; 31 import java.util.LinkedHashMap; 32 import java.util.Map; 33 import java.util.Map.Entry; 34 import java.util.Set; 35 36 import org.apache.hc.core5.annotation.Contract; 37 import org.apache.hc.core5.annotation.ThreadingBehavior; 38 import org.apache.hc.core5.util.Args; 39 40 /** 41 * Maintains a map of objects keyed by a request URI pattern. 42 * <p> 43 * Patterns may have three formats: 44 * </p> 45 * <ul> 46 * <li>{@code *}</li> 47 * <li>{@code *<uri>}</li> 48 * <li>{@code <uri>*}</li> 49 * </ul> 50 * <p> 51 * This class can be used to resolve an object matching a particular request 52 * URI. 53 * </p> 54 * 55 * @param <T> The type of registered objects. 56 * @since 4.0 57 */ 58 @Contract(threading = ThreadingBehavior.SAFE) 59 public class UriPatternMatcher<T> implements LookupRegistry<T> { 60 61 private final Map<String, T> map; 62 63 public UriPatternMatcher() { 64 super(); 65 this.map = new LinkedHashMap<>(); 66 } 67 68 /** 69 * Returns a {@link Set} view of the mappings contained in this matcher. 70 * 71 * @return a set view of the mappings contained in this matcher. 72 * 73 * @see Map#entrySet() 74 * @since 4.4.9 75 */ 76 public synchronized Set<Entry<String, T>> entrySet() { 77 return new HashSet<>(map.entrySet()); 78 } 79 80 /** 81 * Registers the given object for URIs matching the given pattern. 82 * 83 * @param pattern 84 * the pattern to register the handler for. 85 * @param obj 86 * the object. 87 */ 88 @Override 89 public synchronized void register(final String pattern, final T obj) { 90 Args.notNull(pattern, "URI request pattern"); 91 this.map.put(pattern, obj); 92 } 93 94 /** 95 * Removes registered object, if exists, for the given pattern. 96 * 97 * @param pattern 98 * the pattern to unregister. 99 */ 100 @Override 101 public synchronized void unregister(final String pattern) { 102 if (pattern == null) { 103 return; 104 } 105 this.map.remove(pattern); 106 } 107 108 /** 109 * Looks up an object matching the given request path. 110 * 111 * @param path 112 * the request path 113 * @return object or {@code null} if no match is found. 114 */ 115 @Override 116 public synchronized T lookup(final String path) { 117 Args.notNull(path, "Request path"); 118 // direct match? 119 T obj = this.map.get(path); 120 if (obj == null) { 121 // pattern match? 122 String bestMatch = null; 123 for (final String pattern : this.map.keySet()) { 124 if (matchUriRequestPattern(pattern, path)) { 125 // we have a match. is it any better? 126 if (bestMatch == null || (bestMatch.length() < pattern.length()) 127 || (bestMatch.length() == pattern.length() && pattern.endsWith("*"))) { 128 obj = this.map.get(pattern); 129 bestMatch = pattern; 130 } 131 } 132 } 133 } 134 return obj; 135 } 136 137 /** 138 * Tests if the given request path matches the given pattern. 139 * 140 * @param pattern 141 * the pattern 142 * @param path 143 * the request path 144 * @return {@code true} if the request URI matches the pattern, {@code false} otherwise. 145 */ 146 protected boolean matchUriRequestPattern(final String pattern, final String path) { 147 if (pattern.equals("*")) { 148 return true; 149 } 150 return (pattern.endsWith("*") && path.startsWith(pattern.substring(0, pattern.length() - 1))) 151 || (pattern.startsWith("*") && path.endsWith(pattern.substring(1, pattern.length()))); 152 } 153 154 @Override 155 public String toString() { 156 return this.map.toString(); 157 } 158 159 }