/*

 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.sql;

import java.io.InputStream;

/**

 * The representation (mapping) in

 * the Java™ programming

 * language of an SQL

 * <code>BLOB</code> value.  An SQL <code>BLOB</code> is a built-in type

 * that stores a Binary Large Object as a column value in a row of

 * a database table. By default drivers implement <code>Blob</code> using

 * an SQL <code>locator(BLOB)</code>, which means that a

 * <code>Blob</code> object contains a logical pointer to the

 * SQL <code>BLOB</code> data rather than the data itself.

 * A <code>Blob</code> object is valid for the duration of the

 * transaction in which is was created.

 *

 * <P>Methods in the interfaces {@link ResultSet},

 * {@link CallableStatement}, and {@link PreparedStatement}, such as

 * <code>getBlob</code> and <code>setBlob</code> allow a programmer to

 * access an SQL <code>BLOB</code> value.

 * The <code>Blob</code> interface provides methods for getting the

 * length of an SQL <code>BLOB</code> (Binary Large Object) value,

 * for materializing a <code>BLOB</code> value on the client, and for

 * determining the position of a pattern of bytes within a

 * <code>BLOB</code> value. In addition, this interface has methods for updating

 * a <code>BLOB</code> value.

 * <p>

 * All methods on the <code>Blob</code> interface must be fully implemented if the

 * JDBC driver supports the data type.

 *

 * @since 1.2

 */

public interface Blob {

  /**

   * Returns the number of bytes in the <code>BLOB</code> value

   * designated by this <code>Blob</code> object.

   * @return length of the <code>BLOB</code> in bytes

   * @exception SQLException if there is an error accessing the

   * length of the <code>BLOB</code>

   * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

   * this method

   * @since 1.2

   */

  long length() throws SQLException;

  /**

   * Retrieves all or part of the <code>BLOB</code>

   * value that this <code>Blob</code> object represents, as an array of

   * bytes.  This <code>byte</code> array contains up to <code>length</code>

   * consecutive bytes starting at position <code>pos</code>.

   *

   * @param pos the ordinal position of the first byte in the

   *        <code>BLOB</code> value to be extracted; the first byte is at

   *        position 1

   * @param length the number of consecutive bytes to be copied; the value

   * for length must be 0 or greater

   * @return a byte array containing up to <code>length</code>

   *         consecutive bytes from the <code>BLOB</code> value designated

   *         by this <code>Blob</code> object, starting with the

   *         byte at position <code>pos</code>

   * @exception SQLException if there is an error accessing the

   *            <code>BLOB</code> value; if pos is less than 1 or length is

   * less than 0

   * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

   * this method

   * @see #setBytes

   * @since 1.2

   */

  byte[] getBytes(long pos, int length) throws SQLException;

  /**

   * Retrieves the <code>BLOB</code> value designated by this

   * <code>Blob</code> instance as a stream.

   *

   * @return a stream containing the <code>BLOB</code> data

   * @exception SQLException if there is an error accessing the

   *            <code>BLOB</code> value

   * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

   * this method

   * @see #setBinaryStream

   * @since 1.2

   */

  java.io.InputStream getBinaryStream () throws SQLException;

  /**

   * Retrieves the byte position at which the specified byte array

   * <code>pattern</code> begins within the <code>BLOB</code>

   * value that this <code>Blob</code> object represents.  The

   * search for <code>pattern</code> begins at position

   * <code>start</code>.

   *

   * @param pattern the byte array for which to search

   * @param start the position at which to begin searching; the

   *        first position is 1

   * @return the position at which the pattern appears, else -1

   * @exception SQLException if there is an error accessing the

   * <code>BLOB</code> or if start is less than 1

   * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

   * this method

   * @since 1.2

   */

  long position(byte pattern[], long start) throws SQLException;

  /**

   * Retrieves the byte position in the <code>BLOB</code> value

   * designated by this <code>Blob</code> object at which

   * <code>pattern</code> begins.  The search begins at position

   * <code>start</code>.

   *

   * @param pattern the <code>Blob</code> object designating

   * the <code>BLOB</code> value for which to search

   * @param start the position in the <code>BLOB</code> value

   *        at which to begin searching; the first position is 1

   * @return the position at which the pattern begins, else -1

   * @exception SQLException if there is an error accessing the

   *            <code>BLOB</code> value or if start is less than 1

   * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

   * this method

   * @since 1.2

   */

  long position(Blob pattern, long start) throws SQLException;

    // -------------------------- JDBC 3.0 -----------------------------------

    /**

     * Writes the given array of bytes to the <code>BLOB</code> value that

     * this <code>Blob</code> object represents, starting at position

     * <code>pos</code>, and returns the number of bytes written.

     * The array of bytes will overwrite the existing bytes

     * in the <code>Blob</code> object starting at the position

     * <code>pos</code>.  If the end of the <code>Blob</code> value is reached

     * while writing the array of bytes, then the length of the <code>Blob</code>

     * <p>

     * <b>Note:</b> If the value specified for <code>pos</code>

     * is greater then the length+1 of the <code>BLOB</code> value then the

     * behavior is undefined. Some JDBC drivers may throw a

     * <code>SQLException</code> while other drivers may support this

     * operation.

     *

     * @param pos the position in the <code>BLOB</code> object at which

     *        to start writing; the first position is 1

     * @param bytes the array of bytes to be written to the <code>BLOB</code>

     *        value that this <code>Blob</code> object represents

     * @return the number of bytes written

     * @exception SQLException if there is an error accessing the

     *            <code>BLOB</code> value or if pos is less than 1

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @see #getBytes

     * @since 1.4

     */

    int setBytes(long pos, byte[] bytes) throws SQLException;

    /**

     * Writes all or part of the given <code>byte</code> array to the

     * <code>BLOB</code> value that this <code>Blob</code> object represents

     * and returns the number of bytes written.

     * Writing starts at position <code>pos</code> in the <code>BLOB</code>

     * value; <code>len</code> bytes from the given byte array are written.

     * The array of bytes will overwrite the existing bytes

     * in the <code>Blob</code> object starting at the position

     * <code>pos</code>.  If the end of the <code>Blob</code> value is reached

     * while writing the array of bytes, then the length of the <code>Blob</code>

     * <p>

     * <b>Note:</b> If the value specified for <code>pos</code>

     * is greater then the length+1 of the <code>BLOB</code> value then the

     * behavior is undefined. Some JDBC drivers may throw a

     * <code>SQLException</code> while other drivers may support this

     * operation.

     *

     * @param pos the position in the <code>BLOB</code> object at which

     *        to start writing; the first position is 1

     * @param bytes the array of bytes to be written to this <code>BLOB</code>

     *        object

     * @param offset the offset into the array <code>bytes</code> at which

     *        to start reading the bytes to be set

     * @param len the number of bytes to be written to the <code>BLOB</code>

     *        value from the array of bytes <code>bytes</code>

     * @return the number of bytes written

     * @exception SQLException if there is an error accessing the

     *            <code>BLOB</code> value or if pos is less than 1

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @see #getBytes

     * @since 1.4

     */

    int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException;

    /**

     * Retrieves a stream that can be used to write to the <code>BLOB</code>

     * value that this <code>Blob</code> object represents.  The stream begins

     * at position <code>pos</code>.

     * The  bytes written to the stream will overwrite the existing bytes

     * in the <code>Blob</code> object starting at the position

     * <code>pos</code>.  If the end of the <code>Blob</code> value is reached

     * while writing to the stream, then the length of the <code>Blob</code>

     * <p>

     * <b>Note:</b> If the value specified for <code>pos</code>

     * is greater then the length+1 of the <code>BLOB</code> value then the

     * behavior is undefined. Some JDBC drivers may throw a

     * <code>SQLException</code> while other drivers may support this

     * operation.

     *

     * @param pos the position in the <code>BLOB</code> value at which

     *        to start writing; the first position is 1

     * @return a <code>java.io.OutputStream</code> object to which data can

     *         be written

     * @exception SQLException if there is an error accessing the

     *            <code>BLOB</code> value or if pos is less than 1

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @see #getBinaryStream

     * @since 1.4

     */

    java.io.OutputStream setBinaryStream(long pos) throws SQLException;

    /**

     * Truncates the <code>BLOB</code> value that this <code>Blob</code>

     * object represents to be <code>len</code> bytes in length.

     * <p>

     * <b>Note:</b> If the value specified for <code>pos</code>

     * is greater then the length+1 of the <code>BLOB</code> value then the

     * behavior is undefined. Some JDBC drivers may throw a

     * <code>SQLException</code> while other drivers may support this

     * operation.

     *

     * @param len the length, in bytes, to which the <code>BLOB</code> value

     *        that this <code>Blob</code> object represents should be truncated

     * @exception SQLException if there is an error accessing the

     *            <code>BLOB</code> value or if len is less than 0

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @since 1.4

     */

    void truncate(long len) throws SQLException;

    /**

     * This method frees the <code>Blob</code> object and releases the resources that

     * it holds. The object is invalid once the <code>free</code>

     * method is called.

     *<p>

     * After <code>free</code> has been called, any attempt to invoke a

     * method other than <code>free</code> will result in a <code>SQLException</code>

     * being thrown.  If <code>free</code> is called multiple times, the subsequent

     * calls to <code>free</code> are treated as a no-op.

     *<p>

     *

     * @throws SQLException if an error occurs releasing

     * the Blob's resources

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @since 1.6

     */

    void free() throws SQLException;

    /**

     * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value,

     * starting  with the byte specified by pos, which is length bytes in length.

     *

     * @param pos the offset to the first byte of the partial value to be retrieved.

     *  The first byte in the <code>Blob</code> is at position 1

     * @param length the length in bytes of the partial value to be retrieved

     * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.

     * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes

     * in the <code>Blob</code> or if pos + length is greater than the number of bytes

     * in the <code>Blob</code>

     *

     * @exception SQLFeatureNotSupportedException if the JDBC driver does not support

     * this method

     * @since 1.6

     */

    InputStream getBinaryStream(long pos, long length) throws SQLException;

}