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     */
017    package org.apache.commons.fileupload;
018    
019    import 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     * @author Michael C. Macaluso
027     * @since 1.3
028     */
029    public interface FileItemHeaders {
030        /**
031         * Returns the value of the specified part header as a <code>String</code>.
032         * If the part did not include a header of the specified name, this method
033         * return <code>null</code>.  If there are multiple headers with the same
034         * name, this method returns the first header in the item.  The header
035         * name is case insensitive.
036         *
037         * @param name a <code>String</code> specifying the header name
038         * @return a <code>String</code> containing the value of the requested
039         *         header, or <code>null</code> if the item does not have a header
040         *         of that name
041         */
042        String getHeader(String name);
043    
044        /**
045         * <p>
046         * Returns all the values of the specified item header as an
047         * <code>Enumeration</code> of <code>String</code> objects.
048         * </p>
049         * <p>
050         * If the item did not include any headers of the specified name, this
051         * method returns an empty <code>Enumeration</code>. The header name is
052         * case insensitive.
053         * </p>
054         *
055         * @param name a <code>String</code> specifying the header name
056         * @return an <code>Enumeration</code> containing the values of the
057         *         requested header. If the item does not have any headers of
058         *         that name, return an empty <code>Enumeration</code>
059         */
060        Iterator getHeaders(String name);
061    
062        /**
063         * <p>
064         * Returns an <code>Enumeration</code> of all the header names.
065         * </p>
066         * <p>
067         * If the item did not include any headers of the specified name, this
068         * method returns an empty <code>Enumeration</code>. The header name is
069         * case insensitive.
070         * </p>
071         *
072         * @return an <code>Enumeration</code> containing the values of the
073         *         requested header. If the item does not have any headers of
074         *         that name return an empty <code>Enumeration</code>
075         */
076        Iterator getHeaderNames();
077    }