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.regex.Pattern;
34
35 import org.apache.hc.core5.annotation.Contract;
36 import org.apache.hc.core5.annotation.ThreadingBehavior;
37 import org.apache.hc.core5.util.Args;
38
39 /**
40 * Maintains a map of objects keyed by a request URI regular expression.
41 *
42 * <p>
43 * The insertion order is in maintained in that map such that the lookup tests each regex until there is a match. This
44 * class can be used to resolve an object matching a particular request URI.
45 * </p>
46 *
47 * @param <T> The type of registered objects.
48 * @since 5.0
49 */
50 @Contract(threading = ThreadingBehavior.SAFE)
51 public class UriRegexMatcher<T> implements LookupRegistry<T> {
52
53 private final Map<String, T> objectMap;
54 private final Map<String, Pattern> patternMap;
55
56 public UriRegexMatcher() {
57 super();
58 this.objectMap = new LinkedHashMap<>();
59 this.patternMap = new LinkedHashMap<>();
60 }
61
62 /**
63 * Registers the given object for URIs matching the given regex.
64 *
65 * @param regex
66 * the regex to register the handler for.
67 * @param obj
68 * the object.
69 */
70 @Override
71 public synchronized void register(final String regex, final T obj) {
72 Args.notNull(regex, "URI request regex");
73 this.objectMap.put(regex, obj);
74 this.patternMap.put(regex, Pattern.compile(regex));
75 }
76
77 /**
78 * Removes registered object, if exists, for the given regex.
79 *
80 * @param regex
81 * the regex to unregister.
82 */
83 @Override
84 public synchronized void unregister(final String regex) {
85 if (regex == null) {
86 return;
87 }
88 this.objectMap.remove(regex);
89 this.patternMap.remove(regex);
90 }
91
92 /**
93 * Looks up an object matching the given request path.
94 *
95 * @param path
96 * the request path
97 * @return object or {@code null} if no match is found.
98 */
99 @Override
100 public synchronized T lookup(final String path) {
101 Args.notNull(path, "Request path");
102 // direct match?
103 final T obj = this.objectMap.get(path);
104 if (obj == null) {
105 // regex match?
106 for (final Entry<String, Pattern> entry : this.patternMap.entrySet()) {
107 if (entry.getValue().matcher(path).matches()) {
108 return objectMap.get(entry.getKey());
109 }
110 }
111 }
112 return obj;
113 }
114
115 @Override
116 public String toString() {
117 return this.objectMap.toString();
118 }
119
120 }