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</code> POST
024 * request.</p>
025 *
026 * @since 1.2.1
027 *
028 * @version $Id$
029 */
030public interface FileItemHeaders {
031
032    /**
033     * Returns the value of the specified part header as a <code>String</code>.
034     *
035     * If the part did not include a header of the specified name, this method
036     * return <code>null</code>.  If there are multiple headers with the same
037     * name, this method returns the first header in the item.  The header
038     * name is case insensitive.
039     *
040     * @param name a <code>String</code> specifying the header name
041     * @return a <code>String</code> containing the value of the requested
042     *         header, or <code>null</code> if the item does not have a header
043     *         of that name
044     */
045    String getHeader(String name);
046
047    /**
048     * <p>
049     * Returns all the values of the specified item header as an
050     * <code>Iterator</code> of <code>String</code> objects.
051     * </p>
052     * <p>
053     * If the item did not include any headers of the specified name, this
054     * method returns an empty <code>Iterator</code>. The header name is
055     * case insensitive.
056     * </p>
057     *
058     * @param name a <code>String</code> specifying the header name
059     * @return an <code>Iterator</code> containing the values of the
060     *         requested header. If the item does not have any headers of
061     *         that name, return an empty <code>Iterator</code>
062     */
063    Iterator<String> getHeaders(String name);
064
065    /**
066     * <p>
067     * Returns an <code>Iterator</code> of all the header names.
068     * </p>
069     *
070     * @return an <code>Iterator</code> containing all of the names of
071     *         headers provided with this file item. If the item does not have
072     *         any headers return an empty <code>Iterator</code>
073     */
074    Iterator<String> getHeaderNames();
075
076}