    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</code> keys to a <code>List</code> of
    044     * <code>String</code> instances.
    045     */
    046    private final Map<String, List<String>> headerNameToValueListMap = new LinkedHashMap<String, List<String>>();
    047
    048    /**
    049     * {@inheritDoc}
    050     */
    051    @Override
    052    public String getHeader(String name) {
    053        String nameLower = name.toLowerCase(Locale.ENGLISH);
    054        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
    055        if (null == headerValueList) {
    056            return null;
    057        }
    058        return headerValueList.get(0);
    059    }
    060
    061    /**
    062     * {@inheritDoc}
    063     */
    064    @Override
    065    public Iterator<String> getHeaderNames() {
    066        return headerNameToValueListMap.keySet().iterator();
    067    }
    068
    069    /**
    070     * {@inheritDoc}
    071     */
    072    @Override
    073    public Iterator<String> getHeaders(String name) {
    074        String nameLower = name.toLowerCase(Locale.ENGLISH);
    075        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
    076        if (null == headerValueList) {
    077            headerValueList = Collections.emptyList();
    078        }
    079        return headerValueList.iterator();
    080    }
    081
    082    /**
    083     * Method to add header values to this instance.
    084     *
    085     * @param name name of this header
    086     * @param value value of this header
    087     */
    088    public synchronized void addHeader(String name, String value) {
    089        String nameLower = name.toLowerCase(Locale.ENGLISH);
    090        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
    091        if (null == headerValueList) {
    092            headerValueList = new ArrayList<String>();
    093            headerNameToValueListMap.put(nameLower, headerValueList);
    094        }
    095        headerValueList.add(value);
    096    }
    097
    098}