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.LinkedHashMap;
31 import java.util.Map;
32 import java.util.Map.Entry;
33 import java.util.concurrent.locks.ReentrantLock;
34 import java.util.regex.Pattern;
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 regular expression.
42 *
43 * <p>
44 * The insertion order is in maintained in that map such that the lookup tests each regex until there is a match. This
45 * class can be used to resolve an object matching a particular request URI.
46 * </p>
47 *
48 * @param <T> The type of registered objects.
49 * @since 5.0
50 */
51 @Contract(threading = ThreadingBehavior.SAFE)
52 public class UriRegexMatcher<T> implements LookupRegistry<T> {
53
54 private final Map<String, T> objectMap;
55 private final Map<String, Pattern> patternMap;
56
57 private final ReentrantLock lock;
58
59 public UriRegexMatcher() {
60 super();
61 this.objectMap = new LinkedHashMap<>();
62 this.patternMap = new LinkedHashMap<>();
63 this.lock = new ReentrantLock();
64 }
65
66 /**
67 * Registers the given object for URIs matching the given regex.
68 *
69 * @param regex
70 * the regex to register the handler for.
71 * @param obj
72 * the object.
73 */
74 @Override
75 public void register(final String regex, final T obj) {
76 lock.lock();
77 try {
78 Args.notNull(regex, "URI request regex");
79 this.objectMap.put(regex, obj);
80 this.patternMap.put(regex, Pattern.compile(regex));
81 } finally {
82 lock.unlock();
83 }
84 }
85
86 /**
87 * Removes registered object, if exists, for the given regex.
88 *
89 * @param regex
90 * the regex to unregister.
91 */
92 @Override
93 public void unregister(final String regex) {
94 lock.lock();
95 try {
96 if (regex == null) {
97 return;
98 }
99 this.objectMap.remove(regex);
100 this.patternMap.remove(regex);
101 } finally {
102 lock.unlock();
103 }
104 }
105
106 /**
107 * Looks up an object matching the given request path.
108 *
109 * @param path
110 * the request path
111 * @return object or {@code null} if no match is found.
112 */
113 @Override
114 public T lookup(final String path) {
115 lock.lock();
116 try {
117 Args.notNull(path, "Request path");
118 // direct match?
119 final T obj = this.objectMap.get(path);
120 if (obj == null) {
121 // regex match?
122 for (final Entry<String, Pattern> entry : this.patternMap.entrySet()) {
123 if (entry.getValue().matcher(path).matches()) {
124 return objectMap.get(entry.getKey());
125 }
126 }
127 }
128 return obj;
129 } finally {
130 lock.unlock();
131 }
132 }
133
134 @Override
135 public String toString() {
136 return this.objectMap.toString();
137 }
138
139 }