001/****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one   *
003 * or more contributor license agreements.  See the NOTICE file *
004 * distributed with this work for additional information        *
005 * regarding copyright ownership.  The ASF licenses this file   *
006 * to you under the Apache License, Version 2.0 (the            *
007 * "License"); you may not use this file except in compliance   *
008 * with the License.  You may obtain a copy of the License at   *
009 *                                                              *
010 *   http://www.apache.org/licenses/LICENSE-2.0                 *
011 *                                                              *
012 * Unless required by applicable law or agreed to in writing,   *
013 * software distributed under the License is distributed on an  *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
015 * KIND, either express or implied.  See the License for the    *
016 * specific language governing permissions and limitations      *
017 * under the License.                                           *
018 ****************************************************************/
019
020package org.apache.james.mime4j.dom.address;
021
022import java.io.Serializable;
023import java.util.AbstractList;
024import java.util.ArrayList;
025import java.util.Collections;
026import java.util.List;
027
028/**
029 * An immutable, random-access list of Address objects.
030 */
031public class AddressList extends AbstractList<Address> implements Serializable {
032
033    private static final long serialVersionUID = 1L;
034
035    private final List<? extends Address> addresses;
036
037    /**
038     * @param addresses
039     *            A List that contains only Address objects.
040     * @param dontCopy
041     *            true iff it is not possible for the addresses list to be
042     *            modified by someone else.
043     */
044    public AddressList(List<? extends Address> addresses, boolean dontCopy) {
045        if (addresses != null)
046            this.addresses = dontCopy ? addresses : new ArrayList<Address>(
047                    addresses);
048        else
049            this.addresses = Collections.emptyList();
050    }
051
052    /**
053     * The number of elements in this list.
054     */
055    @Override
056    public int size() {
057        return addresses.size();
058    }
059
060    /**
061     * Gets an address.
062     */
063    @Override
064    public Address get(int index) {
065        return addresses.get(index);
066    }
067
068    /**
069     * Returns a flat list of all mailboxes represented in this address list.
070     * Use this if you don't care about grouping.
071     */
072    public MailboxList flatten() {
073        // in the common case, all addresses are mailboxes
074        boolean groupDetected = false;
075        for (Address addr : addresses) {
076            if (!(addr instanceof Mailbox)) {
077                groupDetected = true;
078                break;
079            }
080        }
081
082        if (!groupDetected) {
083            @SuppressWarnings("unchecked")
084            final List<Mailbox> mailboxes = (List<Mailbox>) addresses;
085            return new MailboxList(mailboxes, true);
086        }
087
088        List<Mailbox> results = new ArrayList<Mailbox>();
089        for (Address addr : addresses) {
090            addr.addMailboxesTo(results);
091        }
092
093        // copy-on-construct this time, because subclasses
094        // could have held onto a reference to the results
095        return new MailboxList(results, false);
096    }
097
098}