    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.util;
    018
    019    import java.io.Serializable;
    020    import java.util.ArrayList;
    021    import java.util.Collections;
    022    import java.util.HashMap;
    023    import java.util.Iterator;
    024    import java.util.List;
    025    import java.util.Map;
    026
    027    import org.apache.commons.fileupload.FileItemHeaders;
    028
    029    /**
    030     * Default implementation of the {@link FileItemHeaders} interface.
    031     *
    032     * @author Michael C. Macaluso
    033     * @since 1.3
    034     */
    035    public class FileItemHeadersImpl implements FileItemHeaders, Serializable {
    036        private static final long serialVersionUID = -4455695752627032559L;
    037
    038        /**
    039         * Map of <code>String</code> keys to a <code>List</code> of
    040         * <code>String</code> instances.
    041         */
    042        private final Map headerNameToValueListMap = new HashMap();
    043
    044        /**
    045         * List to preserve order of headers as added.  This would not be
    046         * needed if a <code>LinkedHashMap</code> could be used, but don't
    047         * want to depend on 1.4.
    048         */
    049        private final List headerNameList = new ArrayList();
    050
    051        public String getHeader(String name) {
    052            String nameLower = name.toLowerCase();
    053            List headerValueList = (List) headerNameToValueListMap.get(nameLower);
    054            if (null == headerValueList) {
    055                return null;
    056            }
    057            return (String) headerValueList.get(0);
    058        }
    059
    060        public Iterator getHeaderNames() {
    061            return headerNameList.iterator();
    062        }
    063
    064        public Iterator getHeaders(String name) {
    065            String nameLower = name.toLowerCase();
    066            List headerValueList = (List) headerNameToValueListMap.get(nameLower);
    067            if (null == headerValueList) {
    068                return Collections.EMPTY_LIST.iterator();
    069            }
    070            return headerValueList.iterator();
    071        }
    072
    073        /**
    074         * Method to add header values to this instance.
    075         *
    076         * @param name name of this header
    077         * @param value value of this header
    078         */
    079        public synchronized void addHeader(String name, String value) {
    080            String nameLower = name.toLowerCase();
    081            List headerValueList = (List) headerNameToValueListMap.get(nameLower);
    082            if (null == headerValueList) {
    083                headerValueList = new ArrayList();
    084                headerNameToValueListMap.put(nameLower, headerValueList);
    085                headerNameList.add(nameLower);
    086            }
    087            headerValueList.add(value);
    088        }
    089    }