1 /*
2 * Copyright (c) 2003, 2013, 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 javax.sql.*;
30 import java.io.*;
31 import java.math.*;
32 import java.util.Arrays;
33 import java.util.Map;
34 import java.util.Vector;
35
36 import javax.sql.rowset.*;
37
38 /**
39 * A serialized mapping in the Java programming language of an SQL
40 * structured type. Each attribute that is not already serialized
41 * is mapped to a serialized form, and if an attribute is itself
42 * a structured type, each of its attributes that is not already
43 * serialized is mapped to a serialized form.
44 * <P>
45 * In addition, the structured type is custom mapped to a class in the
46 * Java programming language if there is such a mapping, as are
47 * its attributes, if appropriate.
48 * <P>
49 * The <code>SerialStruct</code> class provides a constructor for creating
50 * an instance from a <code>Struct</code> object, a method for retrieving
51 * the SQL type name of the SQL structured type in the database, and methods
52 * for retrieving its attribute values.
53 *
54 * <h3> Thread safety </h3>
55 *
56 * A SerialStruct is not safe for use by multiple concurrent threads. If a
57 * SerialStruct is to be used by more than one thread then access to the
58 * SerialStruct should be controlled by appropriate synchronization.
59 *
60 * @since 1.5
61 */
62 public class SerialStruct implements Struct, Serializable, Cloneable {
63
64
65 /**
66 * The SQL type name for the structured type that this
67 * <code>SerialStruct</code> object represents. This is the name
68 * used in the SQL definition of the SQL structured type.
69 *
70 * @serial
71 */
72 private String SQLTypeName;
73
74 /**
75 * An array of <code>Object</code> instances in which each
76 * element is an attribute of the SQL structured type that this
77 * <code>SerialStruct</code> object represents. The attributes are
78 * ordered according to their order in the definition of the
79 * SQL structured type.
80 *
81 * @serial
82 */
83 private Object attribs[];
84
85 /**
86 * Constructs a <code>SerialStruct</code> object from the given
87 * <code>Struct</code> object, using the given <code>java.util.Map</code>
88 * object for custom mapping the SQL structured type or any of its
89 * attributes that are SQL structured types.
90 *
91 * @param in an instance of {@code Struct}
92 * @param map a <code>java.util.Map</code> object in which
93 * each entry consists of 1) a <code>String</code> object
94 * giving the fully qualified name of a UDT and 2) the
95 * <code>Class</code> object for the <code>SQLData</code> implementation
96 * that defines how the UDT is to be mapped
97 * @throws SerialException if an error occurs
98 * @see java.sql.Struct
99 */
100 public SerialStruct(Struct in, Map<String,Class<?>> map)
101 throws SerialException
102 {
103
104 try {
105
106 // get the type name
107 SQLTypeName = in.getSQLTypeName();
108 System.out.println("SQLTypeName: " + SQLTypeName);
109
110 // get the attributes of the struct
111 attribs = in.getAttributes(map);
112
113 /*
114 * the array may contain further Structs
115 * and/or classes that have been mapped,
116 * other types that we have to serialize
117 */
118 mapToSerial(map);
119
120 } catch (SQLException e) {
121 throw new SerialException(e.getMessage());
122 }
123 }
124
125 /**
126 * Constructs a <code>SerialStruct</code> object from the
127 * given <code>SQLData</code> object, using the given type
128 * map to custom map it to a class in the Java programming
129 * language. The type map gives the SQL type and the class
130 * to which it is mapped. The <code>SQLData</code> object
131 * defines the class to which the SQL type will be mapped.
132 *
133 * @param in an instance of the <code>SQLData</code> class
134 * that defines the mapping of the SQL structured
135 * type to one or more objects in the Java programming language
136 * @param map a <code>java.util.Map</code> object in which
137 * each entry consists of 1) a <code>String</code> object
138 * giving the fully qualified name of a UDT and 2) the
139 * <code>Class</code> object for the <code>SQLData</code> implementation
140 * that defines how the UDT is to be mapped
141 * @throws SerialException if an error occurs
142 */
143 public SerialStruct(SQLData in, Map<String,Class<?>> map)
144 throws SerialException
145 {
146
147 try {
148
149 //set the type name
150 SQLTypeName = in.getSQLTypeName();
151
152 Vector<Object> tmp = new Vector<>();
153 in.writeSQL(new SQLOutputImpl(tmp, map));
154 attribs = tmp.toArray();
155
156 } catch (SQLException e) {
157 throw new SerialException(e.getMessage());
158 }
159 }
160
161
162 /**
163 * Retrieves the SQL type name for this <code>SerialStruct</code>
164 * object. This is the name used in the SQL definition of the
165 * structured type
166 *
167 * @return a <code>String</code> object representing the SQL
168 * type name for the SQL structured type that this
169 * <code>SerialStruct</code> object represents
170 * @throws SerialException if an error occurs
171 */
172 public String getSQLTypeName() throws SerialException {
173 return SQLTypeName;
174 }
175
176 /**
177 * Retrieves an array of <code>Object</code> values containing the
178 * attributes of the SQL structured type that this
179 * <code>SerialStruct</code> object represents.
180 *
181 * @return an array of <code>Object</code> values, with each
182 * element being an attribute of the SQL structured type
183 * that this <code>SerialStruct</code> object represents
184 * @throws SerialException if an error occurs
185 */
186 public Object[] getAttributes() throws SerialException {
187 Object[] val = this.attribs;
188 return (val == null) ? null : Arrays.copyOf(val, val.length);
189 }
190
191 /**
192 * Retrieves the attributes for the SQL structured type that
193 * this <code>SerialStruct</code> represents as an array of
194 * <code>Object</code> values, using the given type map for
195 * custom mapping if appropriate.
196 *
197 * @param map a <code>java.util.Map</code> object in which
198 * each entry consists of 1) a <code>String</code> object
199 * giving the fully qualified name of a UDT and 2) the
200 * <code>Class</code> object for the <code>SQLData</code> implementation
201 * that defines how the UDT is to be mapped
202 * @return an array of <code>Object</code> values, with each
203 * element being an attribute of the SQL structured
204 * type that this <code>SerialStruct</code> object
205 * represents
206 * @throws SerialException if an error occurs
207 */
208 public Object[] getAttributes(Map<String,Class<?>> map)
209 throws SerialException
210 {
211 Object[] val = this.attribs;
212 return (val == null) ? null : Arrays.copyOf(val, val.length);
213 }
214
215
216 /**
217 * Maps attributes of an SQL structured type that are not
218 * serialized to a serialized form, using the given type map
219 * for custom mapping when appropriate. The following types
220 * in the Java programming language are mapped to their
221 * serialized forms: <code>Struct</code>, <code>SQLData</code>,
222 * <code>Ref</code>, <code>Blob</code>, <code>Clob</code>, and
223 * <code>Array</code>.
224 * <P>
225 * This method is called internally and is not used by an
226 * application programmer.
227 *
228 * @param map a <code>java.util.Map</code> object in which
229 * each entry consists of 1) a <code>String</code> object
230 * giving the fully qualified name of a UDT and 2) the
231 * <code>Class</code> object for the <code>SQLData</code> implementation
232 * that defines how the UDT is to be mapped
233 * @throws SerialException if an error occurs
234 */
235 private void mapToSerial(Map<String,Class<?>> map) throws SerialException {
236
237 try {
238
239 for (int i = 0; i < attribs.length; i++) {
240 if (attribs[i] instanceof Struct) {
241 attribs[i] = new SerialStruct((Struct)attribs[i], map);
242 } else if (attribs[i] instanceof SQLData) {
243 attribs[i] = new SerialStruct((SQLData)attribs[i], map);
244 } else if (attribs[i] instanceof Blob) {
245 attribs[i] = new SerialBlob((Blob)attribs[i]);
246 } else if (attribs[i] instanceof Clob) {
247 attribs[i] = new SerialClob((Clob)attribs[i]);
248 } else if (attribs[i] instanceof Ref) {
249 attribs[i] = new SerialRef((Ref)attribs[i]);
250 } else if (attribs[i] instanceof java.sql.Array) {
251 attribs[i] = new SerialArray((java.sql.Array)attribs[i], map);
252 }
253 }
254
255 } catch (SQLException e) {
256 throw new SerialException(e.getMessage());
257 }
258 return;
259 }
260
261 /**
262 * Compares this SerialStruct to the specified object. The result is
263 * {@code true} if and only if the argument is not {@code null} and is a
264 * {@code SerialStruct} object whose attributes are identical to this
265 * object's attributes
266 *
267 * @param obj The object to compare this {@code SerialStruct} against
268 *
269 * @return {@code true} if the given object represents a {@code SerialStruct}
270 * equivalent to this SerialStruct, {@code false} otherwise
271 *
272 */
273 public boolean equals(Object obj) {
274 if (this == obj) {
275 return true;
276 }
277 if (obj instanceof SerialStruct) {
278 SerialStruct ss = (SerialStruct)obj;
279 return SQLTypeName.equals(ss.SQLTypeName) &&
280 Arrays.equals(attribs, ss.attribs);
281 }
282 return false;
283 }
284
285 /**
286 * Returns a hash code for this {@code SerialStruct}. The hash code for a
287 * {@code SerialStruct} object is computed using the hash codes
288 * of the attributes of the {@code SerialStruct} object and its
289 * {@code SQLTypeName}
290 *
291 * @return a hash code value for this object.
292 */
293 public int hashCode() {
294 return ((31 + Arrays.hashCode(attribs)) * 31) * 31
295 + SQLTypeName.hashCode();
296 }
297
298 /**
299 * Returns a clone of this {@code SerialStruct}. The copy will contain a
300 * reference to a clone of the underlying attribs array, not a reference
301 * to the original underlying attribs array of this {@code SerialStruct} object.
302 *
303 * @return a clone of this SerialStruct
304 */
305 public Object clone() {
306 try {
307 SerialStruct ss = (SerialStruct) super.clone();
308 ss.attribs = Arrays.copyOf(attribs, attribs.length);
309 return ss;
310 } catch (CloneNotSupportedException ex) {
311 // this shouldn't happen, since we are Cloneable
312 throw new InternalError();
313 }
314
315 }
316
317 /**
318 * readObject is called to restore the state of the {@code SerialStruct} from
319 * a stream.
320 */
321 private void readObject(ObjectInputStream s)
322 throws IOException, ClassNotFoundException {
323
324 ObjectInputStream.GetField fields = s.readFields();
325 Object[] tmp = (Object[])fields.get("attribs", null);
326 attribs = tmp == null ? null : tmp.clone();
327 SQLTypeName = (String)fields.get("SQLTypeName", null);
328 }
329
330 /**
331 * writeObject is called to save the state of the {@code SerialStruct}
332 * to a stream.
333 */
334 private void writeObject(ObjectOutputStream s)
335 throws IOException, ClassNotFoundException {
336
337 ObjectOutputStream.PutField fields = s.putFields();
338 fields.put("attribs", attribs);
339 fields.put("SQLTypeName", SQLTypeName);
340 s.writeFields();
341 }
342
343 /**
344 * The identifier that assists in the serialization of this
345 * <code>SerialStruct</code> object.
346 */
347 static final long serialVersionUID = -8322445504027483372L;
348 }