https://openjdk.java.net/ 
/*
 * Copyright (c) 2003, 2019, 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,
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 *
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package javax.sql.rowset.serial;

import java.sql.*;
import java.io.*;
import java.lang.reflect.*;
import java.util.Arrays;



A serialized mapping in the Java programming language of an SQL
BLOB value.


The SerialBlob class provides a constructor for creating
an instance from a Blob object.  Note that the
Blob
object should have brought the SQL BLOB value's data over
to the client before a SerialBlob object
is constructed from it.  The data of an SQL BLOB value can
be materialized on the client as an array of bytes (using the method
Blob.getBytes) or as a stream of uninterpreted bytes
(using the method Blob.getBinaryStream).


SerialBlob methods make it possible to make a copy of a
SerialBlob object as an array of bytes or as a stream.
They also make it possible to locate a given pattern of bytes or a
Blob object within a SerialBlob object
and to update or truncate a Blob object.

 Thread safety 


 A SerialBlob is not safe for use by multiple concurrent threads.  If a
SerialBlob is to be used by more than one thread then access to the SerialBlob
should be controlled by appropriate synchronization.

Author:Jonathan Bruce
Since:1.5
/**
 * A serialized mapping in the Java programming language of an SQL
 * <code>BLOB</code> value.
 * <P>
 * The <code>SerialBlob</code> class provides a constructor for creating
 * an instance from a <code>Blob</code> object.  Note that the
 * <code>Blob</code>
 * object should have brought the SQL <code>BLOB</code> value's data over
 * to the client before a <code>SerialBlob</code> object
 * is constructed from it.  The data of an SQL <code>BLOB</code> value can
 * be materialized on the client as an array of bytes (using the method
 * <code>Blob.getBytes</code>) or as a stream of uninterpreted bytes
 * (using the method <code>Blob.getBinaryStream</code>).
 * <P>
 * <code>SerialBlob</code> methods make it possible to make a copy of a
 * <code>SerialBlob</code> object as an array of bytes or as a stream.
 * They also make it possible to locate a given pattern of bytes or a
 * <code>Blob</code> object within a <code>SerialBlob</code> object
 * and to update or truncate a <code>Blob</code> object.
 *
 * <h2> Thread safety </h2>
 *
 * <p> A SerialBlob is not safe for use by multiple concurrent threads.  If a
 * SerialBlob is to be used by more than one thread then access to the SerialBlob
 * should be controlled by appropriate synchronization.
 *
 * @author Jonathan Bruce
 * @since 1.5
 */
public class SerialBlob implements Blob, Serializable, Cloneable {

    
A serialized array of uninterpreted bytes representing the
value of this SerialBlob object.

@serial
/**
     * A serialized array of uninterpreted bytes representing the
     * value of this <code>SerialBlob</code> object.
     * @serial
     */
    private byte[] buf;

    
The internal representation of the Blob object on which this
SerialBlob object is based.

/**
     * The internal representation of the <code>Blob</code> object on which this
     * <code>SerialBlob</code> object is based.
     */
    @SuppressWarnings("serial") // Not statically typed as Serializable; checked in writeObject
    private Blob blob;

    
The number of bytes in this SerialBlob object's
array of bytes.

@serial
/**
     * The number of bytes in this <code>SerialBlob</code> object's
     * array of bytes.
     * @serial
     */
    private long len;

    
The original number of bytes in this SerialBlob object's
array of bytes when it was first established.

@serial
/**
     * The original number of bytes in this <code>SerialBlob</code> object's
     * array of bytes when it was first established.
     * @serial
     */
    private long origLen;

    
Constructs a SerialBlob object that is a serialized version of
the given byte array.


The new SerialBlob object is initialized with the data from the
byte array, thus allowing disconnected RowSet
objects to establish serialized Blob objects without
touching the data source.

Params:
  • b – the byte array containing the data for the
       Blob object to be serialized
Throws:
/**
     * Constructs a <code>SerialBlob</code> object that is a serialized version of
     * the given <code>byte</code> array.
     * <p>
     * The new <code>SerialBlob</code> object is initialized with the data from the
     * <code>byte</code> array, thus allowing disconnected <code>RowSet</code>
     * objects to establish serialized <code>Blob</code> objects without
     * touching the data source.
     *
     * @param b the <code>byte</code> array containing the data for the
     *        <code>Blob</code> object to be serialized
     * @throws SerialException if an error occurs during serialization
     * @throws SQLException if a SQL errors occurs
     */
    public SerialBlob(byte[] b)
            throws SerialException, SQLException {

        len = b.length;
        buf = new byte[(int)len];
        for(int i = 0; i < len; i++) {
            buf[i] = b[i];
        }
        origLen = len;
    }


    
Constructs a SerialBlob object that is a serialized
version of the given Blob object.


The new SerialBlob object is initialized with the
data from the Blob object; therefore, the
Blob object should have previously brought the
SQL BLOB value's data over to the client from
the database. Otherwise, the new SerialBlob object
will contain no data.

Params:
  • blob – the Blob object from which this
    SerialBlob object is to be constructed;
    cannot be null.
Throws:
See Also:
/**
     * Constructs a <code>SerialBlob</code> object that is a serialized
     * version of the given <code>Blob</code> object.
     * <P>
     * The new <code>SerialBlob</code> object is initialized with the
     * data from the <code>Blob</code> object; therefore, the
     * <code>Blob</code> object should have previously brought the
     * SQL <code>BLOB</code> value's data over to the client from
     * the database. Otherwise, the new <code>SerialBlob</code> object
     * will contain no data.
     *
     * @param blob the <code>Blob</code> object from which this
     *     <code>SerialBlob</code> object is to be constructed;
     *     cannot be null.
     * @throws SerialException if an error occurs during serialization
     * @throws SQLException if the <code>Blob</code> passed to this
     *     to this constructor is a <code>null</code>.
     * @see java.sql.Blob
     */
    public SerialBlob (Blob blob)
            throws SerialException, SQLException {

        if (blob == null) {
            throw new SQLException(
                    "Cannot instantiate a SerialBlob object with a null Blob object");
        }

        len = blob.length();
        buf = blob.getBytes(1, (int)len );
        this.blob = blob;
        origLen = len;
    }

    
Copies the specified number of bytes, starting at the given
position, from this SerialBlob object to
another array of bytes.


Note that if the given number of bytes to be copied is larger than
the length of this SerialBlob object's array of
bytes, the given number will be shortened to the array's length.

Params:
  • pos – the ordinal position of the first byte in this
           SerialBlob object to be copied;
           numbering starts at 1; must not be less
           than 1 and must be less than or equal
           to the length of this SerialBlob object
  • length – the number of bytes to be copied
Throws:
  • SerialException – if the given starting position is out of bounds; if free had previously been called on this object
Returns:an array of bytes that is a copy of a region of this
        SerialBlob object, starting at the given
        position and containing the given number of consecutive bytes
/**
     * Copies the specified number of bytes, starting at the given
     * position, from this <code>SerialBlob</code> object to
     * another array of bytes.
     * <P>
     * Note that if the given number of bytes to be copied is larger than
     * the length of this <code>SerialBlob</code> object's array of
     * bytes, the given number will be shortened to the array's length.
     *
     * @param pos the ordinal position of the first byte in this
     *            <code>SerialBlob</code> object to be copied;
     *            numbering starts at <code>1</code>; must not be less
     *            than <code>1</code> and must be less than or equal
     *            to the length of this <code>SerialBlob</code> object
     * @param length the number of bytes to be copied
     * @return an array of bytes that is a copy of a region of this
     *         <code>SerialBlob</code> object, starting at the given
     *         position and containing the given number of consecutive bytes
     * @throws SerialException if the given starting position is out of bounds;
     * if {@code free} had previously been called on this object
     */
    public byte[] getBytes(long pos, int length) throws SerialException {
        isValid();
        if (length > len) {
            length = (int)len;
        }

        if (pos < 1 || len - pos < 0 ) {
            throw new SerialException("Invalid arguments: position cannot be "
                    + "less than 1 or greater than the length of the SerialBlob");
        }

        pos--; // correct pos to array index

        byte[] b = new byte[length];

        for (int i = 0; i < length; i++) {
            b[i] = this.buf[(int)pos];
            pos++;
        }
        return b;
    }

    
Retrieves the number of bytes in this SerialBlob
object's array of bytes.

Throws:
  • SerialException – if an error occurs; if free had previously been called on this object
Returns:a long indicating the length in bytes of this
        SerialBlob object's array of bytes
/**
     * Retrieves the number of bytes in this <code>SerialBlob</code>
     * object's array of bytes.
     *
     * @return a <code>long</code> indicating the length in bytes of this
     *         <code>SerialBlob</code> object's array of bytes
     * @throws SerialException if an error occurs;
     * if {@code free} had previously been called on this object
     */
    public long length() throws SerialException {
        isValid();
        return len;
    }

    
Returns this SerialBlob object as an input stream.
Unlike the related method, setBinaryStream,
a stream is produced regardless of whether the SerialBlob
was created with a Blob object or a byte array.

Throws:
  • SerialException – if an error occurs; if free had previously been called on this object
See Also:
Returns:a java.io.InputStream object that contains
        this SerialBlob object's array of bytes
/**
     * Returns this <code>SerialBlob</code> object as an input stream.
     * Unlike the related method, <code>setBinaryStream</code>,
     * a stream is produced regardless of whether the <code>SerialBlob</code>
     * was created with a <code>Blob</code> object or a <code>byte</code> array.
     *
     * @return a <code>java.io.InputStream</code> object that contains
     *         this <code>SerialBlob</code> object's array of bytes
     * @throws SerialException if an error occurs;
     * if {@code free} had previously been called on this object
     * @see #setBinaryStream
     */
    public java.io.InputStream getBinaryStream() throws SerialException {
        isValid();
        InputStream stream = new ByteArrayInputStream(buf);
        return stream;
    }

    
Returns the position in this SerialBlob object where
the given pattern of bytes begins, starting the search at the
specified position.

Params:
  • pattern – the pattern of bytes for which to search
  • start – the position of the byte in this
             SerialBlob object from which to begin
             the search; the first position is 1;
             must not be less than 1 nor greater than
             the length of this SerialBlob object
Throws:
  • SerialException – if an error occurs when serializing the blob; if free had previously been called on this object
  • SQLException – if there is an error accessing the BLOB
        value from the database
Returns:the position in this SerialBlob object
        where the given pattern begins, starting at the specified
        position; -1 if the pattern is not found
        or the given starting position is out of bounds; position
        numbering for the return value starts at 1
/**
     * Returns the position in this <code>SerialBlob</code> object where
     * the given pattern of bytes begins, starting the search at the
     * specified position.
     *
     * @param pattern the pattern of bytes for which to search
     * @param start the position of the byte in this
     *              <code>SerialBlob</code> object from which to begin
     *              the search; the first position is <code>1</code>;
     *              must not be less than <code>1</code> nor greater than
     *              the length of this <code>SerialBlob</code> object
     * @return the position in this <code>SerialBlob</code> object
     *         where the given pattern begins, starting at the specified
     *         position; <code>-1</code> if the pattern is not found
     *         or the given starting position is out of bounds; position
     *         numbering for the return value starts at <code>1</code>
     * @throws SerialException if an error occurs when serializing the blob;
     * if {@code free} had previously been called on this object
     * @throws SQLException if there is an error accessing the <code>BLOB</code>
     *         value from the database
     */
    public long position(byte[] pattern, long start)
            throws SerialException, SQLException {

        isValid();
        if (start < 1 || start > len) {
            return -1;
        }

        int pos = (int)start-1; // internally Blobs are stored as arrays.
        int i = 0;
        long patlen = pattern.length;

        while (pos < len) {
            if (pattern[i] == buf[pos]) {
                if (i + 1 == patlen) {
                    return (pos + 1) - (patlen - 1);
                }
                i++; pos++; // increment pos, and i
            } else if (pattern[i] != buf[pos]) {
                pos++; // increment pos only
            }
        }
        return -1; // not found
    }

    
Returns the position in this SerialBlob object where
the given Blob object begins, starting the search at the
specified position.

Params:
  • pattern – the Blob object for which to search;
  • start – the position of the byte in this
             SerialBlob object from which to begin
             the search; the first position is 1;
             must not be less than 1 nor greater than
             the length of this SerialBlob object
Throws:
  • SerialException – if an error occurs when serializing the blob; if free had previously been called on this object
  • SQLException – if there is an error accessing the BLOB
        value from the database
Returns:the position in this SerialBlob object
        where the given Blob object begins, starting
        at the specified position; -1 if the pattern is
        not found or the given starting position is out of bounds;
        position numbering for the return value starts at 1
/**
     * Returns the position in this <code>SerialBlob</code> object where
     * the given <code>Blob</code> object begins, starting the search at the
     * specified position.
     *
     * @param pattern the <code>Blob</code> object for which to search;
     * @param start the position of the byte in this
     *              <code>SerialBlob</code> object from which to begin
     *              the search; the first position is <code>1</code>;
     *              must not be less than <code>1</code> nor greater than
     *              the length of this <code>SerialBlob</code> object
     * @return the position in this <code>SerialBlob</code> object
     *         where the given <code>Blob</code> object begins, starting
     *         at the specified position; <code>-1</code> if the pattern is
     *         not found or the given starting position is out of bounds;
     *         position numbering for the return value starts at <code>1</code>
     * @throws SerialException if an error occurs when serializing the blob;
     * if {@code free} had previously been called on this object
     * @throws SQLException if there is an error accessing the <code>BLOB</code>
     *         value from the database
     */
    public long position(Blob pattern, long start)
            throws SerialException, SQLException {
        isValid();
        return position(pattern.getBytes(1, (int)(pattern.length())), start);
    }

    
Writes the given array of bytes to the BLOB value that
this Blob object represents, starting at position
pos, and returns the number of bytes written.

Params:
  • pos – the position in the SQL BLOB value at which
    to start writing. The first position is 1;
    must not be less than 1 nor greater than
    the length of this SerialBlob object.
  • bytes – the array of bytes to be written to the BLOB
       value that this Blob object represents
Throws:
  • SerialException – if there is an error accessing the
    BLOB value; or if an invalid position is set; if an invalid offset value is set; if free had previously been called on this object
  • SQLException – if there is an error accessing the BLOB
        value from the database
See Also:
Returns:the number of bytes written
/**
     * 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.
     *
     * @param pos the position in the SQL <code>BLOB</code> value at which
     *     to start writing. The first position is <code>1</code>;
     *     must not be less than <code>1</code> nor greater than
     *     the length of this <code>SerialBlob</code> object.
     * @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
     * @throws SerialException if there is an error accessing the
     *     <code>BLOB</code> value; or if an invalid position is set; if an
     *     invalid offset value is set;
     * if {@code free} had previously been called on this object
     * @throws SQLException if there is an error accessing the <code>BLOB</code>
     *         value from the database
     * @see #getBytes
     */
    public int setBytes(long pos, byte[] bytes)
            throws SerialException, SQLException {
        return setBytes(pos, bytes, 0, bytes.length);
    }

    
Writes all or part of the given byte array to the
BLOB value that this Blob object represents
and returns the number of bytes written.
Writing starts at position pos in the BLOB
value; len bytes from the given byte array are written.

Params:
  • pos – the position in the BLOB object at which
    to start writing. The first position is 1;
    must not be less than 1 nor greater than
    the length of this SerialBlob object.
  • bytes – the array of bytes to be written to the BLOB
    value
  • offset – the offset in the byte array at which
    to start reading the bytes. The first offset position is
    0; must not be less than 0 nor greater
    than the length of the byte array
  • length – the number of bytes to be written to the
    BLOB value from the array of bytes bytes.
Throws:
  • SerialException – if there is an error accessing the
    BLOB value; if an invalid position is set; if an
    invalid offset value is set; if number of bytes to be written
    is greater than the SerialBlob length; or the combined values of the length and offset is greater than the Blob buffer; if free had previously been called on this object
  • SQLException – if there is an error accessing the BLOB
        value from the database.
See Also:
Returns:the number of bytes written
/**
     * 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; <i>len</i> bytes from the given byte array are written.
     *
     * @param pos the position in the <code>BLOB</code> object at which
     *     to start writing. The first position is <code>1</code>;
     *     must not be less than <code>1</code> nor greater than
     *     the length of this <code>SerialBlob</code> object.
     * @param bytes the array of bytes to be written to the <code>BLOB</code>
     *     value
     * @param offset the offset in the <code>byte</code> array at which
     *     to start reading the bytes. The first offset position is
     *     <code>0</code>; must not be less than <code>0</code> nor greater
     *     than the length of the <code>byte</code> array
     * @param length the number of bytes to be written to the
     *     <code>BLOB</code> value from the array of bytes <i>bytes</i>.
     *
     * @return the number of bytes written
     * @throws SerialException if there is an error accessing the
     *     <code>BLOB</code> value; if an invalid position is set; if an
     *     invalid offset value is set; if number of bytes to be written
     *     is greater than the <code>SerialBlob</code> length; or the combined
     *     values of the length and offset is greater than the Blob buffer;
     * if {@code free} had previously been called on this object
     * @throws SQLException if there is an error accessing the <code>BLOB</code>
     *         value from the database.
     * @see #getBytes
     */
    public int setBytes(long pos, byte[] bytes, int offset, int length)
            throws SerialException, SQLException {

        isValid();
        if (offset < 0 || offset > bytes.length) {
            throw new SerialException("Invalid offset in byte array set");
        }

        if (pos < 1 || pos > this.length()) {
            throw new SerialException("Invalid position in BLOB object set");
        }

        if ((long)(length) > origLen) {
            throw new SerialException("Buffer is not sufficient to hold the value");
        }

        if ((length + offset) > bytes.length) {
            throw new SerialException("Invalid OffSet. Cannot have combined offset " +
                    "and length that is greater that the Blob buffer");
        }

        int i = 0;
        pos--; // correct to array indexing
        while ( i < length || (offset + i +1) < (bytes.length-offset) ) {
            this.buf[(int)pos + i] = bytes[offset + i ];
            i++;
        }
        return i;
    }

    
Retrieves a stream that can be used to write to the BLOB
value that this Blob object represents.  The stream begins
at position pos. This method forwards the
setBinaryStream() call to the underlying Blob in
the event that this SerialBlob object is instantiated with a
Blob. If this SerialBlob is instantiated with
a byte array, a SerialException is thrown.

Params:
  • pos – the position in the BLOB value at which
       to start writing
Throws:
  • SQLException – if there is an error accessing the
           BLOB value
  • SerialException – if the SerialBlob in not instantiated with a
    Blob object that supports setBinaryStream(); if free had previously been called on this object
See Also:
Returns:a java.io.OutputStream object to which data can
        be written
/**
     * 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>. This method forwards the
     * <code>setBinaryStream()</code> call to the underlying <code>Blob</code> in
     * the event that this <code>SerialBlob</code> object is instantiated with a
     * <code>Blob</code>. If this <code>SerialBlob</code> is instantiated with
     * a <code>byte</code> array, a <code>SerialException</code> is thrown.
     *
     * @param pos the position in the <code>BLOB</code> value at which
     *        to start writing
     * @return a <code>java.io.OutputStream</code> object to which data can
     *         be written
     * @throws SQLException if there is an error accessing the
     *            <code>BLOB</code> value
     * @throws SerialException if the SerialBlob in not instantiated with a
     *     <code>Blob</code> object that supports <code>setBinaryStream()</code>;
     * if {@code free} had previously been called on this object
     * @see #getBinaryStream
     */
    public java.io.OutputStream setBinaryStream(long pos)
            throws SerialException, SQLException {

        isValid();
        if (this.blob != null) {
            return this.blob.setBinaryStream(pos);
        } else {
            throw new SerialException("Unsupported operation. SerialBlob cannot " +
                "return a writable binary stream, unless instantiated with a Blob object " +
                "that provides a setBinaryStream() implementation");
        }
    }

    
Truncates the BLOB value that this Blob
object represents to be len bytes in length.

Params:
  • length – the length, in bytes, to which the BLOB
       value that this Blob object represents should be
       truncated
Throws:
  • SerialException – if there is an error accessing the Blob value; or the length to truncate is greater that the SerialBlob length; if free had previously been called on this object
/**
     * Truncates the <code>BLOB</code> value that this <code>Blob</code>
     * object represents to be <code>len</code> bytes in length.
     *
     * @param length the length, in bytes, to which the <code>BLOB</code>
     *        value that this <code>Blob</code> object represents should be
     *        truncated
     * @throws SerialException if there is an error accessing the Blob value;
     *     or the length to truncate is greater that the SerialBlob length;
     * if {@code free} had previously been called on this object
     */
    public void truncate(long length) throws SerialException {
        isValid();
        if (length > len) {
            throw new SerialException(
                    "Length more than what can be truncated");
        } else if((int)length == 0) {
            buf = new byte[0];
            len = length;
        } else {
            len = length;
            buf = this.getBytes(1, (int)len);
        }
    }


    
Returns an
InputStream object that contains a partial Blob value, starting with the byte specified by pos, which is length bytes in length. 
Params:
  • pos – the offset to the first byte of the partial value to be retrieved. The first byte in the Blob is at position 1
  • length – the length in bytes of the partial value to be retrieved
Throws:
  • SQLException – if pos is less than 1 or if pos is greater than the number of bytes in the Blob or if pos + length is greater than the number of bytes in the Blob
  • SerialException – if the free method had been previously called on this object
Returns:
InputStream through which the partial Blob value can be read.
Since:1.6
/**
     * Returns an
     * <code>InputStream</code> object that contains a partial
     * {@code Blob} 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} 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} 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} or if pos + length is greater than
     * the number of bytes in the {@code Blob}
     * @throws SerialException if the {@code free} method had been previously
     * called on this object
     *
     * @since 1.6
     */
    public InputStream getBinaryStream(long pos, long length) throws SQLException {
        isValid();
        if (pos < 1 || pos > this.length()) {
            throw new SerialException("Invalid position in BLOB object set");
        }
        if (length < 1 || length > len - pos + 1) {
            throw new SerialException(
                    "length is < 1 or pos + length > total number of bytes");
        }
        return new ByteArrayInputStream(buf, (int) pos - 1, (int) length);
    }


    
This method frees the SerialBlob object and releases the resources that it holds. The object is invalid once the free method is called. 
 If free is called multiple times, the subsequent calls to free are treated as a no-op. 


Throws:
  • SQLException – if an error occurs releasing the Blob's resources
Since:1.6
/**
     * This method frees the {@code SerialBlob} object and releases the
     * resources that it holds. The object is invalid once the {@code free}
     * method is called. <p> If {@code free} is called multiple times, the
     * subsequent calls to {@code free} are treated as a no-op. </P>
     *
     * @throws SQLException if an error occurs releasing the Blob's resources
     * @since 1.6
     */
    public void free() throws SQLException {
        if (buf != null) {
            buf = null;
            if (blob != null) {
                blob.free();
            }
            blob = null;
        }
    }

    
Compares this SerialBlob to the specified object. The result is 
true if and only if the argument is not null and is a 
SerialBlob object that represents the same sequence of bytes as this object. 
Params:
  • obj – The object to compare this SerialBlob against
Returns:true if the given object represents a SerialBlob equivalent to this SerialBlob, false otherwise
/**
     * Compares this SerialBlob to the specified object.  The result is {@code
     * true} if and only if the argument is not {@code null} and is a {@code
     * SerialBlob} object that represents the same sequence of bytes as this
     * object.
     *
     * @param  obj The object to compare this {@code SerialBlob} against
     *
     * @return {@code true} if the given object represents a {@code SerialBlob}
     *          equivalent to this SerialBlob, {@code false} otherwise
     *
     */
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof SerialBlob) {
            SerialBlob sb = (SerialBlob)obj;
            if (this.len == sb.len) {
                return Arrays.equals(buf, sb.buf);
            }
        }
        return false;
    }

    
Returns a hash code for this SerialBlob. 
Returns: a hash code value for this object.
/**
     * Returns a hash code for this {@code SerialBlob}.
     * @return  a hash code value for this object.
     */
    public int hashCode() {
       return ((31 + Arrays.hashCode(buf)) * 31 + (int)len) * 31 + (int)origLen;
    }

    
Returns a clone of this SerialBlob. The copy will contain a reference to a clone of the internal byte array, not a reference to the original internal byte array of this SerialBlob object. The underlying Blob object will be set to null. 
Returns: a clone of this SerialBlob
/**
     * Returns a clone of this {@code SerialBlob}. The copy will contain a
     * reference to a clone of the internal byte array, not a reference
     * to the original internal byte array of this {@code SerialBlob} object.
     * The underlying {@code Blob} object will be set to null.
     *
     * @return  a clone of this SerialBlob
     */
    public Object clone() {
        try {
            SerialBlob sb = (SerialBlob) super.clone();
            sb.buf = (buf != null) ? Arrays.copyOf(buf, (int)len) : null;
            sb.blob = null;
            return sb;
        } catch (CloneNotSupportedException ex) {
            // this shouldn't happen, since we are Cloneable
            throw new InternalError();
        }
    }

    
readObject is called to restore the state of the SerialBlob from
a stream.

/**
     * readObject is called to restore the state of the SerialBlob from
     * a stream.
     */
    private void readObject(ObjectInputStream s)
            throws IOException, ClassNotFoundException {

        ObjectInputStream.GetField fields = s.readFields();
        byte[] tmp = (byte[])fields.get("buf", null);
        if (tmp == null)
            throw new InvalidObjectException("buf is null and should not be!");
        buf = tmp.clone();
        len = fields.get("len", 0L);
        if (buf.length != len)
            throw new InvalidObjectException("buf is not the expected size");
        origLen = fields.get("origLen", 0L);
        blob = (Blob) fields.get("blob", null);
    }

    
writeObject is called to save the state of the SerialBlob
to a stream.

/**
     * writeObject is called to save the state of the SerialBlob
     * to a stream.
     */
    private void writeObject(ObjectOutputStream s)
            throws IOException {

        ObjectOutputStream.PutField fields = s.putFields();
        fields.put("buf", buf);
        fields.put("len", len);
        fields.put("origLen", origLen);
        // Note: this check to see if it is an instance of Serializable
        // is for backwards compatibility
        fields.put("blob", blob instanceof Serializable ? blob : null);
        s.writeFields();
    }

    
Check to see if this object had previously had its free method called 
Throws:
/**
     * Check to see if this object had previously had its {@code free} method
     * called
     *
     * @throws SerialException
     */
    private void isValid() throws SerialException {
        if (buf == null) {
            throw new SerialException("Error: You cannot call a method on a " +
                    "SerialBlob instance once free() has been called.");
        }
    }

    
The identifier that assists in the serialization of this SerialBlob object. 
/**
     * The identifier that assists in the serialization of this
     * {@code SerialBlob} object.
     */
    static final long serialVersionUID = -8144641928112860441L;
}