1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.net.smtp;
19
20 import java.util.Enumeration;
21 import java.util.Vector;
22
23 /***
24 * A class used to represent forward and reverse relay paths. The
25 * SMTP MAIL command requires a reverse relay path while the SMTP RCPT
26 * command requires a forward relay path. See RFC 821 for more details.
27 * In general, you will not have to deal with relay paths.
28 * <p>
29 * <p>
30 * @see SMTPClient
31 ***/
32
33 public final class RelayPath
34 {
35 Vector<String> _path;
36 String _emailAddress;
37
38 /***
39 * Create a relay path with the specified email address as the ultimate
40 * destination.
41 * <p>
42 * @param emailAddress The destination email address.
43 ***/
44 public RelayPath(String emailAddress)
45 {
46 _path = new Vector<String>();
47 _emailAddress = emailAddress;
48 }
49
50 /***
51 * Add a mail relay host to the relay path. Hosts are added left to
52 * right. For example, the following will create the path
53 * <code><b> < @bar.com,@foo.com:foobar@foo.com > </b></code>
54 * <pre>
55 * path = new RelayPath("foobar@foo.com");
56 * path.addRelay("bar.com");
57 * path.addRelay("foo.com");
58 * </pre>
59 * <p>
60 * @param hostname The host to add to the relay path.
61 ***/
62 public void addRelay(String hostname)
63 {
64 _path.addElement(hostname);
65 }
66
67 /***
68 * Return the properly formatted string representation of the relay path.
69 * <p>
70 * @return The properly formatted string representation of the relay path.
71 ***/
72 @Override
73 public String toString()
74 {
75 StringBuilder buffer = new StringBuilder();
76 Enumeration<String> hosts;
77
78 buffer.append('<');
79
80 hosts = _path.elements();
81
82 if (hosts.hasMoreElements())
83 {
84 buffer.append('@');
85 buffer.append(hosts.nextElement());
86
87 while (hosts.hasMoreElements())
88 {
89 buffer.append(",@");
90 buffer.append(hosts.nextElement());
91 }
92 buffer.append(':');
93 }
94
95 buffer.append(_emailAddress);
96 buffer.append('>');
97
98 return buffer.toString();
99 }
100
101 }