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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.Locale;
31  import java.util.concurrent.ConcurrentHashMap;
32  import java.util.concurrent.ConcurrentMap;
33  
34  import org.apache.hc.core5.annotation.Contract;
35  import org.apache.hc.core5.annotation.ThreadingBehavior;
36  import org.apache.hc.core5.function.Supplier;
37  import org.apache.hc.core5.http.HttpRequest;
38  import org.apache.hc.core5.http.HttpRequestMapper;
39  import org.apache.hc.core5.http.MisdirectedRequestException;
40  import org.apache.hc.core5.net.URIAuthority;
41  import org.apache.hc.core5.util.Args;
42  
43  /**
44   * Generic registry of request handlers that can be resolved by properties of request messages.
45   *
46   * @param <T> request handler type.
47   *
48   * @since 5.0
49   */
50  @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL)
51  public class RequestHandlerRegistry<T> implements HttpRequestMapper<T> {
52  
53      private final static String LOCALHOST = "localhost";
54  
55      private final String canonicalHostName;
56      private final Supplier<LookupRegistry<T>> registrySupplier;
57      private final LookupRegistry<T> primary;
58      private final ConcurrentMap<String, LookupRegistry<T>> virtualMap;
59  
60      public RequestHandlerRegistry(final String canonicalHostName, final Supplier<LookupRegistry<T>> registrySupplier) {
61          this.canonicalHostName = Args.notNull(canonicalHostName, "Canonical hostname").toLowerCase(Locale.ROOT);
62          this.registrySupplier = registrySupplier != null ? registrySupplier : new Supplier<LookupRegistry<T>>() {
63  
64              @Override
65              public LookupRegistry<T> get() {
66                  return new UriPatternMatcher<>();
67              }
68  
69          };
70          this.primary = this.registrySupplier.get();
71          this.virtualMap = new ConcurrentHashMap<>();
72      }
73  
74      public RequestHandlerRegistry(final String canonicalHostName, final UriPatternType patternType) {
75          this(canonicalHostName, new Supplier<LookupRegistry<T>>() {
76  
77              @Override
78              public LookupRegistry<T> get() {
79                  return UriPatternType.newMatcher(patternType);
80              }
81  
82          });
83      }
84  
85      public RequestHandlerRegistry(final UriPatternType patternType) {
86          this(LOCALHOST, patternType);
87      }
88  
89      public RequestHandlerRegistry() {
90          this(LOCALHOST, UriPatternType.BASIC);
91      }
92  
93      private LookupRegistry<T> getPatternMatcher(final String hostname) {
94          if (hostname == null) {
95              return primary;
96          }
97          if (hostname.equals(canonicalHostName) || hostname.equals(LOCALHOST)) {
98              return primary;
99          }
100         return virtualMap.get(hostname);
101     }
102 
103     @Override
104     public T resolve(final HttpRequest request, final HttpContext context) throws MisdirectedRequestException {
105         final URIAuthority authority = request.getAuthority();
106         final String key = authority != null ? authority.getHostName().toLowerCase(Locale.ROOT) : null;
107         final LookupRegistry<T> patternMatcher = getPatternMatcher(key);
108         if (patternMatcher == null) {
109             throw new MisdirectedRequestException("Not authoritative");
110         }
111         String path = request.getPath();
112         final int i = path.indexOf('?');
113         if (i != -1) {
114             path = path.substring(0, i);
115         }
116         return patternMatcher.lookup(path);
117     }
118 
119     public void register(final String hostname, final String uriPattern, final T object) {
120         Args.notBlank(uriPattern, "URI pattern");
121         if (object == null) {
122             return;
123         }
124         final String key = hostname != null ? hostname.toLowerCase(Locale.ROOT) : null;
125         if (hostname == null || hostname.equals(canonicalHostName) || hostname.equals(LOCALHOST)) {
126             primary.register(uriPattern, object);
127         } else {
128             LookupRegistry<T> patternMatcher = virtualMap.get(key);
129             if (patternMatcher == null) {
130                 final LookupRegistry<T> newPatternMatcher = registrySupplier.get();
131                 patternMatcher = virtualMap.putIfAbsent(key, newPatternMatcher);
132                 if (patternMatcher == null) {
133                     patternMatcher = newPatternMatcher;
134                 }
135             }
136             patternMatcher.register(uriPattern, object);
137         }
138     }
139 
140 }