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.List;
  29 import java.util.Map;
  30 import java.util.Optional;
  31 import java.util.OptionalLong;
  32 
  33 /**
  34  * A read-only view of a set of HTTP headers.
  35  * {@Incubating}
  36  *
  37  * @since 9
  38  */
  39 public interface HttpHeaders {
  40 
  41     /**
  42      * Returns an {@link java.util.Optional} containing the first value of the
  43      * given named (and possibly multi-valued) header. If the header is not
  44      * present, then the returned {@code Optional} is empty.
  45      *
  46      * @param name the header name
  47      * @return an {@code Optional<String>} for the first named value
  48      */
  49     public Optional<String> firstValue(String name);
  50 
  51     /**
  52      * Returns an {@link java.util.OptionalLong} containing the first value of the
  53      * named header field. If the header is not
  54      * present, then the Optional is empty. If the header is present but
  55      * contains a value that does not parse as a {@code Long} value, then an
  56      * exception is thrown.
  57      *
  58      * @param name the header name
  59      * @return  an {@code OptionalLong}
  60      * @throws NumberFormatException if a value is found, but does not parse as
  61      *                               a Long
  62      */
  63     public OptionalLong firstValueAsLong(String name);
  64 
  65     /**
  66      * Returns an unmodifiable List of all of the values of the given named
  67      * header. Always returns a List, which may be empty if the header is not
  68      * present.
  69      *
  70      * @param name the header name
  71      * @return a List of String values
  72      */
  73     public List<String> allValues(String name);
  74 
  75     /**
  76      * Returns an unmodifiable multi Map view of this HttpHeaders. This
  77      * interface should only be used when it is required to iterate over the
  78      * entire set of headers.
  79      *
  80      * @return the Map
  81      */
  82     public Map<String,List<String>> map();
  83 }