1 /* 2 * Copyright (c) 1998, 2006, 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<sup><font size=-2>TM</font></sup> 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 accomodate 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 accomodate 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 accomodate 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 } 305
