1 /*
2 * Copyright (c) 1998, 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 java.sql;
27
28 import java.io.InputStream;
29
30 /**
31 * The representation (mapping) in
32 * the Java™ programming
33 * language of an SQL
34 * <code>BLOB</code> value. An SQL <code>BLOB</code> is a built-in type
35 * that stores a Binary Large Object as a column value in a row of
36 * a database table. By default drivers implement <code>Blob</code> using
37 * an SQL <code>locator(BLOB)</code>, which means that a
38 * <code>Blob</code> object contains a logical pointer to the
39 * SQL <code>BLOB</code> data rather than the data itself.
40 * A <code>Blob</code> object is valid for the duration of the
41 * transaction in which is was created.
42 *
43 * <P>Methods in the interfaces {@link ResultSet},
44 * {@link CallableStatement}, and {@link PreparedStatement}, such as
45 * <code>getBlob</code> and <code>setBlob</code> allow a programmer to
46 * access an SQL <code>BLOB</code> value.
47 * The <code>Blob</code> interface provides methods for getting the
48 * length of an SQL <code>BLOB</code> (Binary Large Object) value,
49 * for materializing a <code>BLOB</code> value on the client, and for
50 * determining the position of a pattern of bytes within a
51 * <code>BLOB</code> value. In addition, this interface has methods for updating
52 * a <code>BLOB</code> value.
53 * <p>
54 * All methods on the <code>Blob</code> interface must be fully implemented if the
55 * JDBC driver supports the data type.
56 *
57 * @since 1.2
58 */
59
60 public interface Blob {
61
62 /**
63 * Returns the number of bytes in the <code>BLOB</code> value
64 * designated by this <code>Blob</code> object.
65 * @return length of the <code>BLOB</code> in bytes
66 * @exception SQLException if there is an error accessing the
67 * length of the <code>BLOB</code>
68 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
69 * this method
70 * @since 1.2
71 */
72 long length() throws SQLException;
73
74 /**
75 * Retrieves all or part of the <code>BLOB</code>
76 * value that this <code>Blob</code> object represents, as an array of
77 * bytes. This <code>byte</code> array contains up to <code>length</code>
78 * consecutive bytes starting at position <code>pos</code>.
79 *
80 * @param pos the ordinal position of the first byte in the
81 * <code>BLOB</code> value to be extracted; the first byte is at
82 * position 1
83 * @param length the number of consecutive bytes to be copied; the value
84 * for length must be 0 or greater
85 * @return a byte array containing up to <code>length</code>
86 * consecutive bytes from the <code>BLOB</code> value designated
87 * by this <code>Blob</code> object, starting with the
88 * byte at position <code>pos</code>
89 * @exception SQLException if there is an error accessing the
90 * <code>BLOB</code> value; if pos is less than 1 or length is
91 * less than 0
92 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
93 * this method
94 * @see #setBytes
95 * @since 1.2
96 */
97 byte[] getBytes(long pos, int length) throws SQLException;
98
99 /**
100 * Retrieves the <code>BLOB</code> value designated by this
101 * <code>Blob</code> instance as a stream.
102 *
103 * @return a stream containing the <code>BLOB</code> data
104 * @exception SQLException if there is an error accessing the
105 * <code>BLOB</code> value
106 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
107 * this method
108 * @see #setBinaryStream
109 * @since 1.2
110 */
111 java.io.InputStream getBinaryStream () throws SQLException;
112
113 /**
114 * Retrieves the byte position at which the specified byte array
115 * <code>pattern</code> begins within the <code>BLOB</code>
116 * value that this <code>Blob</code> object represents. The
117 * search for <code>pattern</code> begins at position
118 * <code>start</code>.
119 *
120 * @param pattern the byte array for which to search
121 * @param start the position at which to begin searching; the
122 * first position is 1
123 * @return the position at which the pattern appears, else -1
124 * @exception SQLException if there is an error accessing the
125 * <code>BLOB</code> or if start is less than 1
126 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
127 * this method
128 * @since 1.2
129 */
130 long position(byte pattern[], long start) throws SQLException;
131
132 /**
133 * Retrieves the byte position in the <code>BLOB</code> value
134 * designated by this <code>Blob</code> object at which
135 * <code>pattern</code> begins. The search begins at position
136 * <code>start</code>.
137 *
138 * @param pattern the <code>Blob</code> object designating
139 * the <code>BLOB</code> value for which to search
140 * @param start the position in the <code>BLOB</code> value
141 * at which to begin searching; the first position is 1
142 * @return the position at which the pattern begins, else -1
143 * @exception SQLException if there is an error accessing the
144 * <code>BLOB</code> value or if start is less than 1
145 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
146 * this method
147 * @since 1.2
148 */
149 long position(Blob pattern, long start) throws SQLException;
150
151 // -------------------------- JDBC 3.0 -----------------------------------
152
153 /**
154 * Writes the given array of bytes to the <code>BLOB</code> value that
155 * this <code>Blob</code> object represents, starting at position
156 * <code>pos</code>, and returns the number of bytes written.
157 * The array of bytes will overwrite the existing bytes
158 * in the <code>Blob</code> object starting at the position
159 * <code>pos</code>. If the end of the <code>Blob</code> value is reached
160 * while writing the array of bytes, then the length of the <code>Blob</code>
161 * value will be increased to accommodate the extra bytes.
162 * <p>
163 * <b>Note:</b> If the value specified for <code>pos</code>
164 * is greater then the length+1 of the <code>BLOB</code> value then the
165 * behavior is undefined. Some JDBC drivers may throw a
166 * <code>SQLException</code> while other drivers may support this
167 * operation.
168 *
169 * @param pos the position in the <code>BLOB</code> object at which
170 * to start writing; the first position is 1
171 * @param bytes the array of bytes to be written to the <code>BLOB</code>
172 * value that this <code>Blob</code> object represents
173 * @return the number of bytes written
174 * @exception SQLException if there is an error accessing the
175 * <code>BLOB</code> value or if pos is less than 1
176 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
177 * this method
178 * @see #getBytes
179 * @since 1.4
180 */
181 int setBytes(long pos, byte[] bytes) throws SQLException;
182
183 /**
184 * Writes all or part of the given <code>byte</code> array to the
185 * <code>BLOB</code> value that this <code>Blob</code> object represents
186 * and returns the number of bytes written.
187 * Writing starts at position <code>pos</code> in the <code>BLOB</code>
188 * value; <code>len</code> bytes from the given byte array are written.
189 * The array of bytes will overwrite the existing bytes
190 * in the <code>Blob</code> object starting at the position
191 * <code>pos</code>. If the end of the <code>Blob</code> value is reached
192 * while writing the array of bytes, then the length of the <code>Blob</code>
193 * value will be increased to accommodate the extra bytes.
194 * <p>
195 * <b>Note:</b> If the value specified for <code>pos</code>
196 * is greater then the length+1 of the <code>BLOB</code> value then the
197 * behavior is undefined. Some JDBC drivers may throw a
198 * <code>SQLException</code> while other drivers may support this
199 * operation.
200 *
201 * @param pos the position in the <code>BLOB</code> object at which
202 * to start writing; the first position is 1
203 * @param bytes the array of bytes to be written to this <code>BLOB</code>
204 * object
205 * @param offset the offset into the array <code>bytes</code> at which
206 * to start reading the bytes to be set
207 * @param len the number of bytes to be written to the <code>BLOB</code>
208 * value from the array of bytes <code>bytes</code>
209 * @return the number of bytes written
210 * @exception SQLException if there is an error accessing the
211 * <code>BLOB</code> value or if pos is less than 1
212 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
213 * this method
214 * @see #getBytes
215 * @since 1.4
216 */
217 int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException;
218
219 /**
220 * Retrieves a stream that can be used to write to the <code>BLOB</code>
221 * value that this <code>Blob</code> object represents. The stream begins
222 * at position <code>pos</code>.
223 * The bytes written to the stream will overwrite the existing bytes
224 * in the <code>Blob</code> object starting at the position
225 * <code>pos</code>. If the end of the <code>Blob</code> value is reached
226 * while writing to the stream, then the length of the <code>Blob</code>
227 * value will be increased to accommodate the extra bytes.
228 * <p>
229 * <b>Note:</b> If the value specified for <code>pos</code>
230 * is greater then the length+1 of the <code>BLOB</code> value then the
231 * behavior is undefined. Some JDBC drivers may throw a
232 * <code>SQLException</code> while other drivers may support this
233 * operation.
234 *
235 * @param pos the position in the <code>BLOB</code> value at which
236 * to start writing; the first position is 1
237 * @return a <code>java.io.OutputStream</code> object to which data can
238 * be written
239 * @exception SQLException if there is an error accessing the
240 * <code>BLOB</code> value or if pos is less than 1
241 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
242 * this method
243 * @see #getBinaryStream
244 * @since 1.4
245 */
246 java.io.OutputStream setBinaryStream(long pos) throws SQLException;
247
248 /**
249 * Truncates the <code>BLOB</code> value that this <code>Blob</code>
250 * object represents to be <code>len</code> bytes in length.
251 * <p>
252 * <b>Note:</b> If the value specified for <code>pos</code>
253 * is greater then the length+1 of the <code>BLOB</code> value then the
254 * behavior is undefined. Some JDBC drivers may throw a
255 * <code>SQLException</code> while other drivers may support this
256 * operation.
257 *
258 * @param len the length, in bytes, to which the <code>BLOB</code> value
259 * that this <code>Blob</code> object represents should be truncated
260 * @exception SQLException if there is an error accessing the
261 * <code>BLOB</code> value or if len is less than 0
262 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
263 * this method
264 * @since 1.4
265 */
266 void truncate(long len) throws SQLException;
267
268 /**
269 * This method frees the <code>Blob</code> object and releases the resources that
270 * it holds. The object is invalid once the <code>free</code>
271 * method is called.
272 * <p>
273 * After <code>free</code> has been called, any attempt to invoke a
274 * method other than <code>free</code> will result in a <code>SQLException</code>
275 * being thrown. If <code>free</code> is called multiple times, the subsequent
276 * calls to <code>free</code> are treated as a no-op.
277 *
278 * @throws SQLException if an error occurs releasing
279 * the Blob's resources
280 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
281 * this method
282 * @since 1.6
283 */
284 void free() throws SQLException;
285
286 /**
287 * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value,
288 * starting with the byte specified by pos, which is length bytes in length.
289 *
290 * @param pos the offset to the first byte of the partial value to be retrieved.
291 * The first byte in the <code>Blob</code> is at position 1
292 * @param length the length in bytes of the partial value to be retrieved
293 * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.
294 * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes
295 * in the <code>Blob</code> or if pos + length is greater than the number of bytes
296 * in the <code>Blob</code>
297 *
298 * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
299 * this method
300 * @since 1.6
301 */
302 InputStream getBinaryStream(long pos, long length) throws SQLException;
303 }