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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.http;
29  
30  /**
31   * One element of an HTTP {@link Header header} value consisting of
32   * a name / value pair and a number of optional name / value parameters.
33   * <p>
34   * Some HTTP headers (such as the set-cookie header) have values that
35   * can be decomposed into multiple elements.  Such headers must be in the
36   * following form:
37   * </p>
38   * <pre>
39   * header  = [ element ] *( "," [ element ] )
40   * element = name [ "=" [ value ] ] *( ";" [ param ] )
41   * param   = name [ "=" [ value ] ]
42   *
43   * name    = token
44   * value   = ( token | quoted-string )
45   *
46   * token         = 1*&lt;any char except "=", ",", ";", &lt;"&gt; and
47   *                       white space&gt;
48   * quoted-string = &lt;"&gt; *( text | quoted-char ) &lt;"&gt;
49   * text          = any char except &lt;"&gt;
50   * quoted-char   = "\" char
51   * </pre>
52   * <p>
53   * Any amount of white space is allowed between any part of the
54   * header, element or param and is ignored. A missing value in any
55   * element or param will be stored as the empty {@link String};
56   * if the "=" is also missing <var>null</var> will be stored instead.
57   *
58   * @since 4.0
59   */
60  public interface HeaderElement {
61  
62      /**
63       * Returns header element name.
64       *
65       * @return header element name
66       */
67      String getName();
68  
69      /**
70       * Returns header element value.
71       *
72       * @return header element value
73       */
74      String getValue();
75  
76      /**
77       * Returns an array of name / value pairs.
78       *
79       * @return array of name / value pairs
80       */
81      NameValuePair[] getParameters();
82  
83      /**
84       * Returns the first parameter with the given name.
85       *
86       * @param name parameter name
87       *
88       * @return name / value pair
89       */
90      NameValuePair getParameterByName(String name);
91  
92      /**
93       * Returns the total count of parameters.
94       *
95       * @return parameter count
96       */
97      int getParameterCount();
98  
99      /**
100      * Returns parameter with the given index.
101      *
102      * @param index
103      * @return name / value pair
104      */
105     NameValuePair getParameter(int index);
106 
107 }
108