001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http;
029
030/**
031 * Represents an HTTP header field.
032 *
033 * <p>The HTTP header fields follow the same generic format as
034 * that given in Section 3.1 of RFC 822. Each header field consists
035 * of a name followed by a colon (":") and the field value. Field names
036 * are case-insensitive. The field value MAY be preceded by any amount
037 * of LWS, though a single SP is preferred.
038 *
039 *<pre>
040 *     message-header = field-name ":" [ field-value ]
041 *     field-name     = token
042 *     field-value    = *( field-content | LWS )
043 *     field-content  = &lt;the OCTETs making up the field-value
044 *                      and consisting of either *TEXT or combinations
045 *                      of token, separators, and quoted-string&gt;
046 *</pre>
047 *
048 * @since 4.0
049 */
050public interface Header {
051
052    /**
053     * Get the name of the Header.
054     *
055     * @return the name of the Header,  never {@code null}
056     */
057    String getName();
058
059    /**
060     * Get the value of the Header.
061     *
062     * @return the value of the Header,  may be {@code null}
063     */
064    String getValue();
065
066    /**
067     * Parses the value.
068     *
069     * @return an array of {@link HeaderElement} entries, may be empty, but is never {@code null}
070     * @throws ParseException in case of a parsing error
071     */
072    HeaderElement[] getElements() throws ParseException;
073
074}