    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.fileupload2.core;
    018
    019import java.util.Iterator;
    020
    021/**
    022 * This class provides support for accessing the headers for a file or form item that was received within a {@code multipart/form-data} POST request.
    023 */
    024public interface FileItemHeaders {
    025
    026    /**
    027     * Adds a header.
    028     *
    029     * @param name  name
    030     * @param value value.
    031     */
    032    void addHeader(String name, String value);
    033
    034    /**
    035     * Gets the value of the specified part header as a {@code String}.
    036     * <p>
    037     * If the part did not include a header of the specified name, this method return {@code null}. If there are multiple headers with the same name, this
    038     * method returns the first header in the item. The header name is case insensitive.
    039     * </p>
    040     *
    041     * @param name a {@code String} specifying the header name
    042     * @return a {@code String} containing the value of the requested header, or {@code null} if the item does not have a header of that name
    043     */
    044    String getHeader(String name);
    045
    046    /**
    047     * Gets an {@code Iterator} of all the header names.
    048     *
    049     * @return an {@code Iterator} containing all of the names of headers provided with this file item. If the item does not have any headers return an empty
    050     *         {@code Iterator}
    051     */
    052    Iterator<String> getHeaderNames();
    053
    054    /**
    055     * Gets all the values of the specified item header as an {@code Iterator} of {@code String} objects.
    056     * <p>
    057     * If the item did not include any headers of the specified name, this method returns an empty {@code Iterator}. The header name is case insensitive.
    058     * </p>
    059     *
    060     * @param name a {@code String} specifying the header name
    061     * @return an {@code Iterator} containing the values of the requested header. If the item does not have any headers of that name, return an empty
    062     *         {@code Iterator}
    063     */
    064    Iterator<String> getHeaders(String name);
    065
    066}