1 /*
2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.sql.rowset.serial;
27
28 import java.sql.*;
29 import java.io.*;
30 import java.net.URL;
31
32
33 /**
34 * A serialized mapping in the Java programming language of an SQL
35 * <code>DATALINK</code> value. A <code>DATALINK</code> value
36 * references a file outside of the underlying data source that the
37 * data source manages.
38 * <P>
39 * <code>RowSet</code> implementations can use the method <code>RowSet.getURL</code>
40 * to retrieve a <code>java.net.URL</code> object, which can be used
41 * to manipulate the external data.
42 * <pre>
43 * java.net.URL url = rowset.getURL(1);
44 * </pre>
45 */
46 public class SerialDatalink implements Serializable, Cloneable {
47
48 /**
49 * The extracted URL field retrieved from the DATALINK field.
50 * @serial
51 */
52 private URL url;
53
54 /**
55 * The SQL type of the elements in this <code>SerialDatalink</code>
56 * object. The type is expressed as one of the contants from the
57 * class <code>java.sql.Types</code>.
58 * @serial
59 */
60 private int baseType;
61
62 /**
63 * The type name used by the DBMS for the elements in the SQL
64 * <code>DATALINK</code> value that this SerialDatalink object
65 * represents.
66 * @serial
67 */
68 private String baseTypeName;
69
70 /**
71 * Constructs a new <code>SerialDatalink</code> object from the given
72 * <code>java.net.URL</code> object.
73 * <P>
74 * @throws SerialException if url parameter is a null
75 */
76 public SerialDatalink(URL url) throws SerialException {
77 if (url == null) {
78 throw new SerialException("Cannot serialize empty URL instance");
79 }
80 this.url = url;
81 }
82
83 /**
84 * Returns a new URL that is a copy of this <code>SerialDatalink</code>
85 * object.
86 *
87 * @return a copy of this <code>SerialDatalink</code> object as a
88 * <code>URL</code> object in the Java programming language.
89 * @throws SerialException if the <code>URL</code> object cannot be de-serialized
90 */
91 public URL getDatalink() throws SerialException {
92
93 URL aURL = null;
94
95 try {
96 aURL = new URL((this.url).toString());
97 } catch (java.net.MalformedURLException e) {
98 throw new SerialException("MalformedURLException: " + e.getMessage());
99 }
100 return aURL;
101 }
102
103 /**
104 * Compares this {@code SerialDatalink} to the specified object.
105 * The result is {@code true} if and only if the argument is not
106 * {@code null} and is a {@code SerialDatalink} object whose URL is
107 * identical to this object's URL
108 *
109 * @param obj The object to compare this {@code SerialDatalink} against
110 *
111 * @return {@code true} if the given object represents a {@code SerialDatalink}
112 * equivalent to this SerialDatalink, {@code false} otherwise
113 *
114 */
115 public boolean equals(Object obj) {
116 if (this == obj) {
117 return true;
118 }
119 if (obj instanceof SerialDatalink) {
120 SerialDatalink sdl = (SerialDatalink) obj;
121 return url.equals(sdl.url);
122 }
123 return false;
124 }
125
126 /**
127 * Returns a hash code for this {@code SerialDatalink}. The hash code for a
128 * {@code SerialDatalink} object is taken as the hash code of
129 * the {@code URL} it stores
130 *
131 * @return a hash code value for this object.
132 */
133 public int hashCode() {
134 return 31 + url.hashCode();
135 }
136
137 /**
138 * Returns a clone of this {@code SerialDatalink}.
139 *
140 * @return a clone of this SerialDatalink
141 */
142 public Object clone() {
143 try {
144 SerialDatalink sdl = (SerialDatalink) super.clone();
145 return sdl;
146 } catch (CloneNotSupportedException ex) {
147 // this shouldn't happen, since we are Cloneable
148 throw new InternalError();
149 }
150 }
151
152 /**
153 * readObject is called to restore the state of the {@code SerialDatalink}
154 * from a stream.
155 */
156 private void readObject(ObjectInputStream s)
157 throws IOException, ClassNotFoundException {
158 s.defaultReadObject();
159 }
160
161 /**
162 * writeObject is called to save the state of the {@code SerialDatalink}
163 * to a stream.
164 */
165 private void writeObject(ObjectOutputStream s)
166 throws IOException {
167 s.defaultWriteObject();
168 }
169
170 /**
171 * The identifier that assists in the serialization of this <code>SerialDatalink</code>
172 * object.
173 */
174 static final long serialVersionUID = 2826907821828733626L;
175 }