Source code: net/jxta/codat/Codat.java
1 /*
2 * Copyright (c) 2001 Sun Microsystems, Inc. All rights
3 * reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *0
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. The end-user documentation included with the redistribution,
18 * if any, must include the following acknowledgment:
19 * "This product includes software developed by the
20 * Sun Microsystems, Inc. for Project JXTA."
21 * Alternately, this acknowledgment may appear in the software itself,
22 * if and wherever such third-party acknowledgments normally appear.
23 *
24 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
25 * not be used to endorse or promote products derived from this
26 * software without prior written permission. For written
27 * permission, please contact Project JXTA at http://www.jxta.org.
28 *
29 * 5. Products derived from this software may not be called "JXTA",
30 * nor may "JXTA" appear in their name, without prior written
31 * permission of Sun.
32 *
33 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36 * DISCLAIMED. IN NO EVENT SHALL SUN MICROSYSTEMS OR
37 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of Project JXTA. For more
49 * information on Project JXTA, please see
50 * <http://www.jxta.org/>.
51 *
52 * This license is based on the BSD license adopted by the Apache Foundation.
53 *
54 * $Id: Codat.java,v 1.14 2002/10/02 19:07:28 hamada Exp $
55 */
56
57 package net.jxta.codat;
58
59 import java.io.IOException;
60
61 import net.jxta.id.ID;
62 import net.jxta.id.IDFactory;
63 import net.jxta.peergroup.PeerGroupID;
64 import net.jxta.document.Document;
65
66 /**
67 * Codats are container objects that can hold both data or code and are
68 * associated with a JXTA ID. The Codat class is offered as a standard way for
69 * applications and services to exchange any kind of contents via a common API and
70 * associate a unique JXTA id to these contents.
71 *
72 * <p>Codats are containers objects that are used to hold any kinds of
73 * objects or data. A codat can represent a file, a class file, the saved
74 * state of an application, a loadable C library. Codats are handled
75 * transparently by the JXTA platform, and are used as placeholders for
76 * any types of data. Codats hold Document that represent the data that
77 * they hold.</p>
78 *
79 * <p>Codats are published in peer groups. A Codat can belong to only one peer
80 * group. Multiple copies of a codat can be made to be published in multiple
81 * peer groups.</p>
82 *
83 * <p>Codats are uniquely identified via a unique CodatID. This Id
84 * is guaranteed to be unique within the JXTA world.</p>
85 *
86 * <p>The core manipulates two main types of codats:</p>
87 * <ul type-disc>
88 * <li><b>Codat</b> - hold data or code</li>
89 * <li><b>Metadata</b> - hold information about another Codat</li>
90 * </ul>
91 *
92 * <p>The JXTA platform defines Codat as the unit of information shared and
93 * exchanged within a JXTA group. All instances of Codats reside within a
94 * peer group. The PeerGroup content caching service provides storage and retrieval
95 * methods for codats using codatId as index.</p>
96 *
97 * @see net.jxta.codat.CodatID
98 * @see net.jxta.document.Document
99 * @see net.jxta.document.StructuredDocument
100 * @see net.jxta.document.StructuredTextDocument
101 *
102 **/
103 public class Codat {
104
105 /**
106 * Id of this Codat. This is the "address" which may be used to
107 * refer to this Codat. see {@link net.jxta.codat.CodatID}
108 **/
109 protected ID id = ID.nullID;
110
111 /**
112 * Codat Id of a Codat to which this Codat is related. This may be the
113 * Codat Id of another codat in the same Peer Group or nullID
114 **/
115 protected ID metaId = ID.nullID;
116
117 /**
118 * A JXTA Document which contains the data held by this Codat.
119 **/
120 protected Document doc = null;
121
122 /**
123 * Makes a new Codat with a new CodatId given a PeerGroupID and a document.
124 *
125 * @param groupID PeerGroupID the group to which this
126 * codat will belong.
127 * @param about CodatId for which this Codat is metadata
128 * @param document Document held by this codat.
129 * @throws IOException if there is an error accessing the document.
130 **/
131 public Codat( PeerGroupID groupID, ID about, Document document) throws IOException {
132
133 this.id = IDFactory.newCodatID( groupID, document.getStream() );
134
135 this.metaId = about;
136 this.doc = document;
137 }
138
139 /**
140 * Makes a new Codat instance from an existing Codat,
141 * with a given CodatID and a document.
142 *
143 * @param id CodatId of the new codat
144 * @param about CodatID for which this Codat is metadata
145 * @param document Document hold by this codat
146 **/
147 public Codat( CodatID id, CodatID about, Document document) {
148 this.id = id;
149 this.metaId = about;
150 this.doc = document;
151 }
152
153 /**
154 * Returns the CodatId associated with this Codat.
155 *
156 * @return CodateID associated with this codat
157 **/
158 public ID getCodatID() {
159 return id;
160 }
161
162 /**
163 * Returns Codat id of related codat associated with this metadata Codat.
164 *
165 * @return CodateID associated with this codat
166 *
167 **/
168 public ID getMetaID() {
169 return metaId;
170 }
171
172 /**
173 * Returns the Document associated with this Codat.
174 *
175 *
176 * @return Document associated with this Codat
177 **/
178 public Document getDocument() {
179 return doc;
180 }
181 }