    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
    018    package org.apache.commons.net.smtp;
    019
    020    import java.util.Enumeration;
    021    import java.util.Vector;
    022
    023    /***
    024     * A class used to represent forward and reverse relay paths.  The
    025     * SMTP MAIL command requires a reverse relay path while the SMTP RCPT
    026     * command requires a forward relay path.  See RFC 821 for more details.
    027     * In general, you will not have to deal with relay paths.
    028     * <p>
    029     * <p>
    030     * @see SMTPClient
    031     ***/
    032
    033    public final class RelayPath
    034    {
    035        Vector<String> _path;
    036        String _emailAddress;
    037
    038        /***
    039         * Create a relay path with the specified email address as the ultimate
    040         * destination.
    041         * <p>
    042         * @param emailAddress The destination email address.
    043         ***/
    044        public RelayPath(String emailAddress)
    045        {
    046            _path = new Vector<String>();
    047            _emailAddress = emailAddress;
    048        }
    049
    050        /***
    051         * Add a mail relay host to the relay path.  Hosts are added left to
    052         * right.  For example, the following will create the path
    053         * <code><b> &lt @bar.com,@foo.com:foobar@foo.com &gt </b></code>
    054         * <pre>
    055         * path = new RelayPath("foobar@foo.com");
    056         * path.addRelay("bar.com");
    057         * path.addRelay("foo.com");
    058         * </pre>
    059         * <p>
    060         * @param hostname The host to add to the relay path.
    061         ***/
    062        public void addRelay(String hostname)
    063        {
    064            _path.addElement(hostname);
    065        }
    066
    067        /***
    068         * Return the properly formatted string representation of the relay path.
    069         * <p>
    070         * @return The properly formatted string representation of the relay path.
    071         ***/
    072        @Override
    073        public String toString()
    074        {
    075            StringBuilder buffer = new StringBuilder();
    076            Enumeration<String> hosts;
    077
    078            buffer.append('<');
    079
    080            hosts = _path.elements();
    081
    082            if (hosts.hasMoreElements())
    083            {
    084                buffer.append('@');
    085                buffer.append(hosts.nextElement());
    086
    087                while (hosts.hasMoreElements())
    088                {
    089                    buffer.append(",@");
    090                    buffer.append(hosts.nextElement());
    091                }
    092                buffer.append(':');
    093            }
    094
    095            buffer.append(_emailAddress);
    096            buffer.append('>');
    097
    098            return buffer.toString();
    099        }
    100
    101    }