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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
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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
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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      *<p>
278      *
279      * @throws SQLException if an error occurs releasing
280      * the Blob's resources
281      * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
282      * this method
283      * @since 1.6
284      */
285     void free() throws SQLException;
286 
287     /**
288      * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value,
289      * starting  with the byte 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 retrieved.
292      *  The first byte in the <code>Blob</code> is at position 1
293      * @param length the length in bytes of the partial value to be retrieved
294      * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.
295      * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes
296      * in the <code>Blob</code> or if pos + length is greater than the number of bytes
297      * in the <code>Blob</code>
298      *
299      * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
300      * this method
301      * @since 1.6
302      */
303     InputStream getBinaryStream(long pos, long length) throws SQLException;
304 }