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.text.SimpleDateFormat;
21 import java.util.Date;
22 import java.util.Locale;
23
24 /**
25 * This class is used to construct a bare minimum acceptable header for an email message. To construct more complicated headers you should refer to RFC 5322.
26 * When the Java Mail API is finalized, you will be able to use it to compose fully compliant Internet text messages.
27 * <p>
28 * The main purpose of the class is to facilitate the mail sending process, by relieving the programmer from having to explicitly format a simple message
29 * header. For example:
30 * </p>
31 *
32 * <pre>
33 * writer = client.sendMessageData();
34 * if (writer == null) // failure
35 * return false;
36 * header =
37 * new SimpleSMTPHeader("foobar@foo.com", "foo@bar.com" "Just testing");
38 * header.addCC("bar@foo.com");
39 * header.addHeaderField("Organization", "Foobar, Inc.");
40 * writer.write(header.toString());
41 * writer.write("This is just a test");
42 * writer.close();
43 * if (!client.completePendingCommand()) // failure
44 * return false;
45 * </pre>
46 *
47 * @see SMTPClient
48 */
49
50 public class SimpleSMTPHeader {
51 private final String subject;
52 private final String from;
53 private final String to;
54 private final StringBuffer headerFields;
55 private boolean hasHeaderDate;
56 private StringBuffer cc;
57
58 /**
59 * Creates a new SimpleSMTPHeader instance initialized with the given from, to, and subject header field values.
60 *
61 * @param from The value of the <code>From:</code> header field. This should be the sender's email address. Must not be null.
62 * @param to The value of the <code>To:</code> header field. This should be the recipient's email address. May be null
63 * @param subject The value of the <code>Subject:</code> header field. This should be the subject of the message. May be null
64 */
65 public SimpleSMTPHeader(final String from, final String to, final String subject) {
66 if (from == null) {
67 throw new IllegalArgumentException("From cannot be null");
68 }
69 this.to = to;
70 this.from = from;
71 this.subject = subject;
72 this.headerFields = new StringBuffer();
73 this.cc = null;
74 }
75
76 /**
77 * Add an email address to the CC (carbon copy or courtesy copy) list.
78 *
79 * @param address The email address to add to the CC list.
80 */
81 public void addCC(final String address) {
82 if (cc == null) {
83 cc = new StringBuffer();
84 } else {
85 cc.append(", ");
86 }
87
88 cc.append(address);
89 }
90
91 /**
92 * Adds an arbitrary header field with the given value to the article header. These headers will be written before the
93 * {@code From}, {@code To}, {@code Subject}, and {@code Cc} fields when the SimpleSMTPHeader is converted to a string.
94 * An example use would be:
95 *
96 * <pre>
97 * header.addHeaderField("Organization", "Foobar, Inc.");
98 * </pre>
99 *
100 * @param headerField The header field to add, not including the colon.
101 * @param value The value of the added header field.
102 */
103 public void addHeaderField(final String headerField, final String value) {
104 if (!hasHeaderDate && "Date".equals(headerField)) {
105 hasHeaderDate = true;
106 }
107 headerFields.append(headerField);
108 headerFields.append(": ");
109 headerFields.append(value);
110 headerFields.append('\n');
111 }
112
113 /**
114 * Converts the SimpleSMTPHeader to a properly formatted header in the form of a String, including the blank line used to separate the header from the
115 * article body. The header fields CC and Subject are only included when they are non-null.
116 *
117 * @return The message header in the form of a String.
118 */
119 @Override
120 public String toString() {
121 final StringBuilder header = new StringBuilder();
122
123 final String pattern = "EEE, dd MMM yyyy HH:mm:ss Z"; // Fri, 21 Nov 1997 09:55:06 -0600
124 final SimpleDateFormat format = new SimpleDateFormat(pattern, Locale.ENGLISH);
125
126 if (!hasHeaderDate) {
127 addHeaderField("Date", format.format(new Date()));
128 }
129 if (headerFields.length() > 0) {
130 header.append(headerFields.toString());
131 }
132
133 header.append("From: ").append(from).append("\n");
134
135 if (to != null) {
136 header.append("To: ").append(to).append("\n");
137 }
138
139 if (cc != null) {
140 header.append("Cc: ").append(cc.toString()).append("\n");
141 }
142
143 if (subject != null) {
144 header.append("Subject: ").append(subject).append("\n");
145 }
146
147 header.append('\n'); // end of headers; body follows
148
149 return header.toString();
150 }
151 }