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.util;
018
019import java.io.Serializable;
020import java.util.ArrayList;
021import java.util.Collections;
022import java.util.Iterator;
023import java.util.LinkedHashMap;
024import java.util.List;
025import java.util.Locale;
026import java.util.Map;
027
028import org.apache.commons.fileupload.FileItemHeaders;
029
030/**
031 * Default implementation of the {@link FileItemHeaders} interface.
032 *
033 * @since 1.2.1
034 */
035public class FileItemHeadersImpl implements FileItemHeaders, Serializable {
036
037    /**
038     * Serial version UID, being used, if serialized.
039     */
040    private static final long serialVersionUID = -4455695752627032559L;
041
042    /**
043     * Map of {@code String} keys to a {@code List} of
044     * {@code String} instances.
045     */
046    private final Map<String, List<String>> headerNameToValueListMap = new LinkedHashMap<>();
047
048    /**
049     * Constructs a new instance.
050     */
051    public FileItemHeadersImpl() {
052        // empty
053    }
054
055    /**
056     * Method to add header values to this instance.
057     *
058     * @param name name of this header
059     * @param value value of this header
060     */
061    public synchronized void addHeader(final String name, final String value) {
062        final String nameLower = name.toLowerCase(Locale.ROOT);
063        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
064        if (null == headerValueList) {
065            headerValueList = new ArrayList<>();
066            headerNameToValueListMap.put(nameLower, headerValueList);
067        }
068        headerValueList.add(value);
069    }
070
071    @Override
072    public String getHeader(final String name) {
073        final String nameLower = name.toLowerCase(Locale.ROOT);
074        final List<String> headerValueList = headerNameToValueListMap.get(nameLower);
075        if (null == headerValueList) {
076            return null;
077        }
078        return headerValueList.get(0);
079    }
080
081    @Override
082    public Iterator<String> getHeaderNames() {
083        return headerNameToValueListMap.keySet().iterator();
084    }
085
086    @Override
087    public Iterator<String> getHeaders(final String name) {
088        final String nameLower = name.toLowerCase(Locale.ROOT);
089        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
090        if (null == headerValueList) {
091            headerValueList = Collections.emptyList();
092        }
093        return headerValueList.iterator();
094    }
095
096}