1 /*
   2  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.incubator.http;
  27 
  28 import java.util.ArrayList;
  29 import java.util.List;
  30 import java.util.Map;
  31 import java.util.Optional;
  32 import java.util.OptionalLong;
  33 import java.util.TreeMap;
  34 import java.util.function.Predicate;
  35 import static java.util.Collections.emptyList;
  36 import static java.util.Collections.emptyMap;
  37 import static java.util.Collections.unmodifiableList;
  38 import static java.util.Collections.unmodifiableMap;
  39 import static java.util.Objects.requireNonNull;
  40 
  41 final class ImmutableHeaders implements HttpHeaders {
  42 
  43     private final Map<String, List<String>> map;
  44 
  45     public static ImmutableHeaders empty() {
  46         return of(emptyMap());
  47     }
  48 
  49     public static ImmutableHeaders of(Map<String, List<String>> src) {
  50         return of(src, x -> true);
  51     }
  52 
  53     public static ImmutableHeaders of(Map<String, List<String>> src,
  54                                       Predicate<? super String> keyAllowed) {
  55         requireNonNull(src, "src");
  56         requireNonNull(keyAllowed, "keyAllowed");
  57         return new ImmutableHeaders(src, keyAllowed);
  58     }
  59 
  60     private ImmutableHeaders(Map<String, List<String>> src,
  61                              Predicate<? super String> keyAllowed) {
  62         Map<String, List<String>> m = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
  63         src.entrySet().stream()
  64                 .filter(e -> keyAllowed.test(e.getKey()))
  65                 .forEach(e ->
  66                         {
  67                             List<String> values = new ArrayList<>(e.getValue());
  68                             m.put(e.getKey(), unmodifiableList(values));
  69                         }
  70                 );
  71         this.map = unmodifiableMap(m);
  72     }
  73 
  74     @Override
  75     public Optional<String> firstValue(String name) {
  76         return allValues(name).stream().findFirst();
  77     }
  78 
  79     @Override
  80     public OptionalLong firstValueAsLong(String name) {
  81         return allValues(name).stream().mapToLong(Long::valueOf).findFirst();
  82     }
  83 
  84     @Override
  85     public List<String> allValues(String name) {
  86         requireNonNull(name);
  87         List<String> values = map.get(name);
  88         // Making unmodifiable list out of empty in order to make a list which
  89         // throws UOE unconditionally
  90         return values != null ? values : unmodifiableList(emptyList());
  91     }
  92 
  93     @Override
  94     public Map<String, List<String>> map() {
  95         return map;
  96     }
  97 }