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 26package java.sql; 27 28import 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 59public 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} 307