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 import java.util.concurrent.locks.ReentrantLock;
36
37 import org.apache.hc.core5.annotation.Contract;
38 import org.apache.hc.core5.annotation.ThreadingBehavior;
39 import org.apache.hc.core5.util.Args;
40
41 /**
42 * Maintains a map of objects keyed by a request URI pattern.
43 * <p>
44 * Patterns may have three formats:
45 * </p>
46 * <ul>
47 * <li>{@code *}</li>
48 * <li>{@code *<uri>}</li>
49 * <li>{@code <uri>*}</li>
50 * </ul>
51 * <p>
52 * This class can be used to resolve an object matching a particular request
53 * URI.
54 * </p>
55 *
56 * @param <T> The type of registered objects.
57 * @since 5.0
58 */
59 @Contract(threading = ThreadingBehavior.SAFE)
60 public class UriPatternOrderedMatcher<T> implements LookupRegistry<T> {
61
62 private final Map<String, T> map;
63
64 private final ReentrantLock lock = new ReentrantLock();
65
66 public UriPatternOrderedMatcher() {
67 super();
68 this.map = new LinkedHashMap<>();
69 }
70
71 /**
72 * Returns a {@link Set} view of the mappings contained in this matcher.
73 *
74 * @return a set view of the mappings contained in this matcher.
75 *
76 * @see Map#entrySet()
77 * @since 4.4.9
78 */
79 public Set<Entry<String, T>> entrySet() {
80 lock.lock();
81 try {
82 return new HashSet<>(map.entrySet());
83 } finally {
84 lock.unlock();
85 }
86 }
87
88 /**
89 * Registers the given object for URIs matching the given pattern.
90 *
91 * @param pattern the pattern to register the handler for.
92 * @param obj the object.
93 */
94 @Override
95 public void register(final String pattern, final T obj) {
96 lock.lock();
97 try {
98 Args.notNull(pattern, "URI request pattern");
99 this.map.put(pattern, obj);
100 } finally {
101 lock.unlock();
102 }
103 }
104
105 /**
106 * Removes registered object, if exists, for the given pattern.
107 *
108 * @param pattern the pattern to unregister.
109 */
110 @Override
111 public void unregister(final String pattern) {
112 lock.lock();
113 try {
114 if (pattern == null) {
115 return;
116 }
117 this.map.remove(pattern);
118 } finally {
119 lock.unlock();
120 }
121 }
122
123 /**
124 * Looks up an object matching the given request path.
125 *
126 * @param path the request path
127 * @return object or {@code null} if no match is found.
128 */
129 @Override
130 public T lookup(final String path) {
131 lock.lock();
132 try {
133 Args.notNull(path, "Request path");
134 for (final Entry<String, T> entry : this.map.entrySet()) {
135 final String pattern = entry.getKey();
136 if (path.equals(pattern)) {
137 return entry.getValue();
138 }
139 if (matchUriRequestPattern(pattern, path)) {
140 return this.map.get(pattern);
141 }
142 }
143 return null;
144 } finally {
145 lock.unlock();
146 }
147 }
148
149 /**
150 * Tests if the given request path matches the given pattern.
151 *
152 * @param pattern the pattern
153 * @param path the request path
154 * @return {@code true} if the request URI matches the pattern, {@code false}
155 * otherwise.
156 */
157 protected boolean matchUriRequestPattern(final String pattern, final String path) {
158 if (pattern.equals("*")) {
159 return true;
160 }
161 return (pattern.endsWith("*") && path.startsWith(pattern.substring(0, pattern.length() - 1)))
162 || (pattern.startsWith("*") && path.endsWith(pattern.substring(1)));
163 }
164
165 @Override
166 public String toString() {
167 return this.map.toString();
168 }
169
170 }