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
018package 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 * @author Daniel F. Savarese
046 * @see NNTPClient
047 ***/
048
049public class SimpleNNTPHeader
050{
051    private String __subject, __from;
052    private StringBuilder __newsgroups;
053    private StringBuilder __headerFields;
054    private int __newsgroupCount;
055
056    /***
057     * Creates a new SimpleNNTPHeader instance initialized with the given
058     * from and subject header field values.
059     * <p>
060     * @param from  The value of the <code>From:</code> header field.  This
061     *              should be the article poster's email address.
062     * @param subject  The value of the <code>Subject:</code> header field.
063     *              This should be the subject of the article.
064     ***/
065    public SimpleNNTPHeader(String from, String subject)
066    {
067        __from = from;
068        __subject = subject;
069        __newsgroups = new StringBuilder();
070        __headerFields = new StringBuilder();
071        __newsgroupCount = 0;
072    }
073
074    /***
075     * Adds a newsgroup to the article <code>Newsgroups:</code> field.
076     * <p>
077     * @param newsgroup  The newsgroup to add to the article's newsgroup
078     *                   distribution list.
079     ***/
080    public void addNewsgroup(String newsgroup)
081    {
082        if (__newsgroupCount++ > 0)
083            __newsgroups.append(',');
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        StringBuffer header = new StringBuffer();
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        header.append('\n');
161
162        return header.toString();
163    }
164}