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.nntp;
019
020 /***
021 * This class is used to construct the bare minimum
022 * acceptable header for most news readers. To construct more
023 * complicated headers you should refer to RFC 822. When the
024 * Java Mail API is finalized, you will be
025 * able to use it to compose fully compliant Internet text messages.
026 * <p>
027 * The main purpose of the class is to faciliatate the article posting
028 * process, by relieving the programmer from having to explicitly format
029 * an article header. For example:
030 * <pre>
031 * writer = client.postArticle();
032 * if(writer == null) // failure
033 * return false;
034 * header = new SimpleNNTPHeader("foobar@foo.com", "Just testing");
035 * header.addNewsgroup("alt.test");
036 * header.addHeaderField("Organization", "Foobar, Inc.");
037 * writer.write(header.toString());
038 * writer.write("This is just a test");
039 * writer.close();
040 * if(!client.completePendingCommand()) // failure
041 * return false;
042 * </pre>
043 * <p>
044 * <p>
045 * @see NNTPClient
046 ***/
047
048 public class SimpleNNTPHeader
049 {
050 private String __subject, __from;
051 private StringBuilder __newsgroups;
052 private StringBuilder __headerFields;
053 private int __newsgroupCount;
054
055 /***
056 * Creates a new SimpleNNTPHeader instance initialized with the given
057 * from and subject header field values.
058 * <p>
059 * @param from The value of the <code>From:</code> header field. This
060 * should be the article poster's email address.
061 * @param subject The value of the <code>Subject:</code> header field.
062 * This should be the subject of the article.
063 ***/
064 public SimpleNNTPHeader(String from, String subject)
065 {
066 __from = from;
067 __subject = subject;
068 __newsgroups = new StringBuilder();
069 __headerFields = new StringBuilder();
070 __newsgroupCount = 0;
071 }
072
073 /***
074 * Adds a newsgroup to the article <code>Newsgroups:</code> field.
075 * <p>
076 * @param newsgroup The newsgroup to add to the article's newsgroup
077 * distribution list.
078 ***/
079 public void addNewsgroup(String newsgroup)
080 {
081 if (__newsgroupCount++ > 0) {
082 __newsgroups.append(',');
083 }
084 __newsgroups.append(newsgroup);
085 }
086
087 /***
088 * Adds an arbitrary header field with the given value to the article
089 * header. These headers will be written after the From, Newsgroups,
090 * and Subject fields when the SimpleNNTPHeader is convertered to a string.
091 * An example use would be:
092 * <pre>
093 * header.addHeaderField("Organization", "Foobar, Inc.");
094 * </pre>
095 * <p>
096 * @param headerField The header field to add, not including the colon.
097 * @param value The value of the added header field.
098 ***/
099 public void addHeaderField(String headerField, String value)
100 {
101 __headerFields.append(headerField);
102 __headerFields.append(": ");
103 __headerFields.append(value);
104 __headerFields.append('\n');
105 }
106
107
108 /***
109 * Returns the address used in the <code> From: </code> header field.
110 * <p>
111 * @return The from address.
112 ***/
113 public String getFromAddress()
114 {
115 return __from;
116 }
117
118 /***
119 * Returns the subject used in the <code> Subject: </code> header field.
120 * <p>
121 * @return The subject.
122 ***/
123 public String getSubject()
124 {
125 return __subject;
126 }
127
128 /***
129 * Returns the contents of the <code> Newsgroups: </code> header field.
130 * <p>
131 * @return The comma-separated list of newsgroups to which the article
132 * is being posted.
133 ***/
134 public String getNewsgroups()
135 {
136 return __newsgroups.toString();
137 }
138
139 /***
140 * Converts the SimpleNNTPHeader to a properly formatted header in
141 * the form of a String, including the blank line used to separate
142 * the header from the article body.
143 * <p>
144 * @return The article header in the form of a String.
145 ***/
146 @Override
147 public String toString()
148 {
149 StringBuilder header = new StringBuilder();
150
151 header.append("From: ");
152 header.append(__from);
153 header.append("\nNewsgroups: ");
154 header.append(__newsgroups.toString());
155 header.append("\nSubject: ");
156 header.append(__subject);
157 header.append('\n');
158 if (__headerFields.length() > 0) {
159 header.append(__headerFields.toString());
160 }
161 header.append('\n');
162
163 return header.toString();
164 }
165 }