001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.fileupload;
018
019import java.util.Iterator;
020
021/**
022 * <p> This class provides support for accessing the headers for a file or form
023 * item that was received within a {@code multipart/form-data} POST
024 * request.</p>
025 *
026 * @since 1.2.1
027 */
028public interface FileItemHeaders {
029
030    /**
031     * Returns the value of the specified part header as a {@code String}.
032     *
033     * If the part did not include a header of the specified name, this method
034     * return {@code null}.  If there are multiple headers with the same
035     * name, this method returns the first header in the item.  The header
036     * name is case insensitive.
037     *
038     * @param name a {@code String} specifying the header name
039     * @return a {@code String} containing the value of the requested
040     *         header, or {@code null} if the item does not have a header
041     *         of that name
042     */
043    String getHeader(String name);
044
045    /**
046     * <p>
047     * Returns an {@code Iterator} of all the header names.
048     * </p>
049     *
050     * @return an {@code Iterator} containing all of the names of
051     *         headers provided with this file item. If the item does not have
052     *         any headers return an empty {@code Iterator}
053     */
054    Iterator<String> getHeaderNames();
055
056    /**
057     * <p>
058     * Returns all the values of the specified item header as an
059     * {@code Iterator} of {@code String} objects.
060     * </p>
061     * <p>
062     * If the item did not include any headers of the specified name, this
063     * method returns an empty {@code Iterator}. The header name is
064     * case insensitive.
065     * </p>
066     *
067     * @param name a {@code String} specifying the header name
068     * @return an {@code Iterator} containing the values of the
069     *         requested header. If the item does not have any headers of
070     *         that name, return an empty {@code Iterator}
071     */
072    Iterator<String> getHeaders(String name);
073
074}