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    
020    package org.apache.james.mime4j.dom.address;
021    
022    import java.io.Serializable;
023    import java.util.AbstractList;
024    import java.util.ArrayList;
025    import java.util.Collections;
026    import java.util.List;
027    
028    /**
029     * An immutable, random-access list of Address objects.
030     */
031    public 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    }