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package javax.sql.rowset.serial;

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


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.

Author:Jonathan Bruce
/** * 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. * * @author Jonathan Bruce */
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. */
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 orginal number of bytes in this SerialBlob object's array of bytes when it was first established.
@serial
/** * The orginal 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; //if ( len < 10240000) // len = 10240000; 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:
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 */
public byte[] getBytes(long pos, int length) throws SerialException { if (length > len) { length = (int)len; } if (pos < 1 || length - pos < 0 ) { throw new SerialException("Invalid arguments: position cannot be less that 1"); } 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:
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 */
public long length() throws SerialException { 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:
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 * @see #setBinaryStream */
public java.io.InputStream getBinaryStream() throws SerialException { InputStream stream = new ByteArrayInputStream(buf); return (java.io.InputStream)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
  • 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 * @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 { 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
  • 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 * @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 { 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
  • 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 * @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
  • 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 * @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 { 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()
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> * @see #getBinaryStream */
public java.io.OutputStream setBinaryStream(long pos) throws SerialException, SQLException { if (this.blob.setBinaryStream(pos) != 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
/** * 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 */
public void truncate(long length) throws SerialException { 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
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</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> * * @since 1.6 */
public InputStream getBinaryStream(long pos,long length) throws SQLException { throw new java.lang.UnsupportedOperationException("Not supported"); }
This method frees the Blob object and releases the resources that it holds. Blob object. 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>Blob</code> object and releases the resources that it holds. * <code>Blob</code> object. The object is invalid once the <code>free</code> * method is called. If <code>free</code> is called multiple times, the subsequent * calls to <code>free</code> are treated as a no-op. * * @throws SQLException if an error occurs releasing * the Blob's resources * @since 1.6 */
public void free() throws SQLException { throw new java.lang.UnsupportedOperationException("Not supported"); }
The identifier that assists in the serialization of this SerialBlob object.
/** * The identifier that assists in the serialization of this <code>SerialBlob</code> * object. */
static final long serialVersionUID = -8144641928112860441L; }