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 language of an SQL
33 * {@code BLOB} value. An SQL {@code BLOB} is a built-in type
34 * that stores a Binary Large Object as a column value in a row of
35 * a database table. By default drivers implement {@code Blob} using
36 * an SQL {@code locator(BLOB)}, which means that a
37 * {@code Blob} object contains a logical pointer to the
38 * SQL {@code BLOB} data rather than the data itself.
39 * A {@code Blob} object is valid for the duration of the
40 * transaction in which is was created.
41 *
42 * <P>Methods in the interfaces {@link ResultSet},
43 * {@link CallableStatement}, and {@link PreparedStatement}, such as
44 * {@code getBlob} and {@code setBlob} allow a programmer to
45 * access an SQL {@code BLOB} value.
46 * The {@code Blob} interface provides methods for getting the
47 * length of an SQL {@code BLOB} (Binary Large Object) value,
48 * for materializing a {@code BLOB} value on the client, and for
49 * determining the position of a pattern of bytes within a
50 * {@code BLOB} value. In addition, this interface has methods for updating
51 * a {@code BLOB} value.
52 * <p>
53 * All methods on the {@code Blob} interface must be fully implemented if the
54 * JDBC driver supports the data type.
55 *
56 * @since 1.2
57 */
58
59 public interface Blob {
60
61 /**
62 * Returns the number of bytes in the {@code BLOB} value
63 * designated by this {@code Blob} object.
64 *
65 * @return length of the {@code BLOB} in bytes
66 * @exception SQLException if there is an error accessing the
67 * length of the {@code BLOB}
68 * @exception SQLFeatureNotSupportedException if the JDBC driver
69 * does not support this method
70 * @since 1.2
71 */
72 long length() throws SQLException;
73
74 /**
75 * Retrieves all or part of the {@code BLOB}
76 * value that this {@code Blob} object represents, as an array of
77 * bytes. This {@code byte} array contains up to {@code length}
78 * consecutive bytes starting at position {@code pos}.
79 *
80 * @param pos the ordinal position of the first byte in the
81 * {@code BLOB} 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}
86 * consecutive bytes from the {@code BLOB} value designated
87 * by this {@code Blob} object, starting with the
88 * byte at position {@code pos}
89 * @exception SQLException if there is an error accessing the
90 * {@code BLOB} value; if pos is less than 1 or length is
91 * less than 0
92 * @exception SQLFeatureNotSupportedException if the JDBC driver
93 * does not support 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} value designated by this
101 * {@code Blob} instance as a stream.
102 *
103 * @return a stream containing the {@code BLOB} data
104 * @exception SQLException if there is an error accessing the
105 * {@code BLOB} value
106 * @exception SQLFeatureNotSupportedException if the JDBC driver
107 * does not support 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} begins within the {@code BLOB}
116 * value that this {@code Blob} object represents.
117 * The search for {@code pattern} begins at position
118 * {@code start}.
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} or if start is less than 1
126 * @exception SQLFeatureNotSupportedException if the JDBC driver
127 * does not support 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} value
134 * designated by this {@code Blob} object at which
135 * {@code pattern} begins. The search begins at position
136 * {@code start}.
137 *
138 * @param pattern the {@code Blob} object designating
139 * the {@code BLOB} value for which to search
140 * @param start the position in the {@code BLOB} 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} value or if start is less than 1
145 * @exception SQLFeatureNotSupportedException if the JDBC driver
146 * does not support 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} value that
155 * this {@code Blob} object represents, starting at position
156 * {@code pos}, and returns the number of bytes written.
157 * The array of bytes will overwrite the existing bytes
158 * in the {@code Blob} object starting at the position
159 * {@code pos}. If the end of the {@code Blob} value is reached
160 * while writing the array of bytes, then the length of the {@code Blob}
161 * value will be increased to accommodate the extra bytes.
162 * <p>
163 * <b>Note:</b> If the value specified for {@code pos}
164 * is greater than the length+1 of the {@code BLOB} value then the
165 * behavior is undefined. Some JDBC drivers may throw an
166 * {@code SQLException} while other drivers may support this
167 * operation.
168 *
169 * @param pos the position in the {@code BLOB} 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}
172 * value that this {@code Blob} object represents
173 * @return the number of bytes written
174 * @exception SQLException if there is an error accessing the
175 * {@code BLOB} value or if pos is less than 1
176 * @exception SQLFeatureNotSupportedException if the JDBC driver
177 * does not support 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} array to the
185 * {@code BLOB} value that this {@code Blob} object represents
186 * and returns the number of bytes written.
187 * Writing starts at position {@code pos} in the {@code BLOB}
188 * value; {@code len} bytes from the given byte array are written.
189 * The array of bytes will overwrite the existing bytes
190 * in the {@code Blob} object starting at the position
191 * {@code pos}. If the end of the {@code Blob} value is reached
192 * while writing the array of bytes, then the length of the {@code Blob}
193 * value will be increased to accommodate the extra bytes.
194 * <p>
195 * <b>Note:</b> If the value specified for {@code pos}
196 * is greater than the length+1 of the {@code BLOB} value then the
197 * behavior is undefined. Some JDBC drivers may throw an
198 * {@code SQLException} while other drivers may support this
199 * operation.
200 *
201 * @param pos the position in the {@code BLOB} 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}
204 * object
205 * @param offset the offset into the array {@code bytes} 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}
208 * value from the array of bytes {@code bytes}
209 * @return the number of bytes written
210 * @exception SQLException if there is an error accessing the
211 * {@code BLOB} value or if pos is less than 1
212 * @exception SQLFeatureNotSupportedException if the JDBC driver
213 * does not support 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}
221 * value that this {@code Blob} object represents. The stream begins
222 * at position {@code pos}.
223 * The bytes written to the stream will overwrite the existing bytes
224 * in the {@code Blob} object starting at the position
225 * {@code pos}. If the end of the {@code Blob} value is reached
226 * while writing to the stream, then the length of the {@code Blob}
227 * value will be increased to accommodate the extra bytes.
228 * <p>
229 * <b>Note:</b> If the value specified for {@code pos}
230 * is greater than the length+1 of the {@code BLOB} value then the
231 * behavior is undefined. Some JDBC drivers may throw an
232 * {@code SQLException} while other drivers may support this
233 * operation.
234 *
235 * @param pos the position in the {@code BLOB} value at which
236 * to start writing; the first position is 1
237 * @return a {@code java.io.OutputStream} object to which data can
238 * be written
239 * @exception SQLException if there is an error accessing the
240 * {@code BLOB} value or if pos is less than 1
241 * @exception SQLFeatureNotSupportedException if the JDBC driver
242 * does not support 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} value that this {@code Blob}
250 * object represents to be {@code len} bytes in length.
251 * <p>
252 * <b>Note:</b> If the value specified for {@code pos}
253 * is greater than the length+1 of the {@code BLOB} value then the
254 * behavior is undefined. Some JDBC drivers may throw an
255 * {@code SQLException} while other drivers may support this
256 * operation.
257 *
258 * @param len the length, in bytes, to which the {@code BLOB} value
259 * that this {@code Blob} object represents should be truncated
260 * @exception SQLException if there is an error accessing the
261 * {@code BLOB} value or if len is less than 0
262 * @exception SQLFeatureNotSupportedException if the JDBC driver
263 * does not support this method
264 * @since 1.4
265 */
266 void truncate(long len) throws SQLException;
267
268 /**
269 * This method frees the {@code Blob} object and releases the resources that
270 * it holds. The object is invalid once the {@code free}
271 * method is called.
272 * <p>
273 * After {@code free} has been called, any attempt to invoke a
274 * method other than {@code free} will result in an {@code SQLException}
275 * being thrown. If {@code free} is called multiple times, the subsequent
276 * calls to {@code free} 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
281 * does not support this method
282 * @since 1.6
283 */
284 void free() throws SQLException;
285
286 /**
287 * Returns an {@code InputStream} object that contains
288 * a partial {@code Blob} value, starting with the byte
289 * specified by pos, which is length bytes in length.
290 *
291 * @param pos the offset to the first byte of the partial value to be
292 * retrieved. The first byte in the {@code Blob} is at position 1.
293 * @param length the length in bytes of the partial value to be retrieved
294 * @return {@code InputStream} through which
295 * the partial {@code Blob} value can be read.
296 * @throws SQLException if pos is less than 1 or if pos is greater
297 * than the number of bytes in the {@code Blob} or if
298 * pos + length is greater than the number of bytes
299 * in the {@code Blob}
300 *
301 * @exception SQLFeatureNotSupportedException if the JDBC driver
302 * does not support this method
303 * @since 1.6
304 */
305 InputStream getBinaryStream(long pos, long length) throws SQLException;
306 }