    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     * @author Daniel F. Savarese
    031     * @see SMTPClient
    032     ***/
    033
    034    public final class RelayPath
    035    {
    036        Vector<String> _path;
    037        String _emailAddress;
    038
    039        /***
    040         * Create a relay path with the specified email address as the ultimate
    041         * destination.
    042         * <p>
    043         * @param emailAddress The destination email address.
    044         ***/
    045        public RelayPath(String emailAddress)
    046        {
    047            _path = new Vector<String>();
    048            _emailAddress = emailAddress;
    049        }
    050
    051        /***
    052         * Add a mail relay host to the relay path.  Hosts are added left to
    053         * right.  For example, the following will create the path
    054         * <code><b> &lt @bar.com,@foo.com:foobar@foo.com &gt </b></code>
    055         * <pre>
    056         * path = new RelayPath("foobar@foo.com");
    057         * path.addRelay("bar.com");
    058         * path.addRelay("foo.com");
    059         * </pre>
    060         * <p>
    061         * @param hostname The host to add to the relay path.
    062         ***/
    063        public void addRelay(String hostname)
    064        {
    065            _path.addElement(hostname);
    066        }
    067
    068        /***
    069         * Return the properly formatted string representation of the relay path.
    070         * <p>
    071         * @return The properly formatted string representation of the relay path.
    072         ***/
    073        @Override
    074        public String toString()
    075        {
    076            StringBuilder buffer = new StringBuilder();
    077            Enumeration<String> hosts;
    078
    079            buffer.append('<');
    080
    081            hosts = _path.elements();
    082
    083            if (hosts.hasMoreElements())
    084            {
    085                buffer.append('@');
    086                buffer.append(hosts.nextElement());
    087
    088                while (hosts.hasMoreElements())
    089                {
    090                    buffer.append(",@");
    091                    buffer.append(hosts.nextElement());
    092                }
    093                buffer.append(':');
    094            }
    095
    096            buffer.append(_emailAddress);
    097            buffer.append('>');
    098
    099            return buffer.toString();
    100        }
    101
    102    }