| java.lang.Object
 org.hsqldb.jdbc.jdbcBlob
| jdbcBlob | | public class jdbcBlob implements Blob(Code) | | The representation (mapping) in the JavaTM
programming language of an SQL BLOB value.
Provides methods for getting the length of an SQL BLOB (Binary Large Object)
value, for materializing a BLOB value on the client, and for determining the
position of an octet sequence (byte pattern) within a BLOB value.
HSQLDB-Specific Information:
Including 1.8.x, the HSQLDB driver does not implement Blob using an SQL
locator(BLOB). That is, an HSQLDB Blob object does not contain a logical
pointer to SQL BLOB data; rather it directly contains a representation of
the data (a byte array). As a result, an HSQLDB Blob object is itself
valid beyond the duration of the transaction in which is was created,
although it does not necessarily represent a corresponding value
on the database.
Currently, the interface methods for updating a BLOB value are
unsupported. However, the truncate method is supported for local use.
author:
james house jhouse@part.net
author:
boucherb@users
version:
1.7.2
since:
JDK 1.2, HSQLDB 1.7.2 |
| Field Summary | |
| volatile byte[] | data
|
| Constructor Summary | |
| public | jdbcBlob(byte[] data)
Constructs a new jdbcBlob instance wrapping the given octet sequence. |
| Method Summary | |
| public InputStream | getBinaryStream()
Retrieves the BLOB value designated by this
Blob instance as a stream. | | public byte[] | getBytes(long pos, int length)
Retrieves all or part of the BLOB value that this
Blob object represents, as an array of bytes. | | public long | length()
Returns the number of bytes in the BLOB value
designated by this Blob object. | | public long | position(byte[] pattern, long start)
Retrieves the byte position at which the specified byte array
pattern begins within the BLOB
value that this Blob object represents. | | public long | position(Blob pattern, long start)
Retrieves the byte position in the BLOB value
designated by this Blob object at which
pattern begins. | | public OutputStream | setBinaryStream(long pos)
Retrieves a stream that can be used to write to the BLOB
value that this Blob object represents. | | public int | setBytes(long pos, byte[] bytes)
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. | | public int | setBytes(long pos, byte[] bytes, int offset, int len)
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. | | public void | truncate(long len)
Truncates the BLOB value that this Blob
object represents to be len bytes in length. |
| data | | volatile byte[] data(Code) | | |
| jdbcBlob | | public jdbcBlob(byte[] data) throws SQLException(Code) | | Constructs a new jdbcBlob instance wrapping the given octet sequence.
This constructor is used internally to retrieve result set values as
Blob objects, yet it must be public to allow access from other packages.
As such (in the interest of efficiency) this object maintains a reference
to the given octet sequence rather than making a copy; special care
should be taken by extenal clients never to use this constructor with a
byte array object that may later be modified extenally.
Parameters:
data - the octet sequence representing the Blob value
throws:
SQLException - if the argument is null |
| getBytes | | public byte[] getBytes(long pos, int length) throws SQLException(Code) | | Retrieves all or part of the BLOB value that this
Blob object represents, as an array of bytes. This
byte array contains up to length
consecutive bytes starting at position pos.
HSQLDB-Specific Information:
The official specification above is ambiguous in that it does not
precisely indicate the policy to be observed when
pos > this.length() - length. One policy would be to retrieve the
octets from pos to this.length(). Another would be to throw an
exception. HSQLDB observes the later policy.
Parameters:
pos - the ordinal position of the first byte in theBLOB value to be extracted; the first byte is atposition 1
Parameters:
length - the number of consecutive bytes to be copied a byte array containing up to lengthconsecutive bytes from the BLOB value designatedby this Blob object, starting with thebyte at position pos
exception:
SQLException - if there is an error accessing theBLOB value
See Also: jdbcBlob.setBytes
since:
JDK 1.2, HSQLDB 1.7.2 |
| length | | public long length() throws SQLException(Code) | | Returns the number of bytes in the BLOB value
designated by this Blob object.
length of the BLOB in bytes
exception:
SQLException - if there is an error accessing thelength of the BLOB
since:
JDK 1.2, HSQLDB 1.7.2 |
| position | | public long position(byte[] pattern, long start) throws SQLException(Code) | | Retrieves the byte position at which the specified byte array
pattern begins within the BLOB
value that this Blob object represents. The
search for pattern begins at position
start.
Parameters:
pattern - the byte array for which to search
Parameters:
start - the position at which to begin searching; thefirst position is 1 the position at which the pattern appears, else -1
exception:
SQLException - if there is an error accessing theBLOB
since:
JDK 1.2, HSQLDB 1.7.2 |
| position | | public long position(Blob pattern, long start) throws SQLException(Code) | | Retrieves the byte position in the BLOB value
designated by this Blob object at which
pattern begins. The search begins at position
start.
Parameters:
pattern - the Blob object designatingthe BLOB value for which to search
Parameters:
start - the position in the BLOB valueat which to begin searching; the first position is 1 the position at which the pattern begins, else -1
exception:
SQLException - if there is an error accessing theBLOB value
since:
JDK 1.2, HSQLDB 1.7.2 |
| setBinaryStream | | public OutputStream setBinaryStream(long pos) throws SQLException(Code) | | Retrieves a stream that can be used to write to the BLOB
value that this Blob object represents. The stream begins
at position pos.
HSQLDB-Specific Information:
HSQLDB 1.7.2 does not support this feature.
Calling this method always throws an SQLException.
Parameters:
pos - the position in the BLOB value at whichto start writing a java.io.OutputStream object to which data canbe written
exception:
SQLException - if there is an error accessing theBLOB value
See Also: jdbcBlob.getBinaryStream
since:
JDK 1.4, HSQLDB 1.7.2 |
| setBytes | | public int setBytes(long pos, byte[] bytes) throws SQLException(Code) | | 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.
HSQLDB-Specific Information:
HSLQDB 1.7.2 does not support this feature.
Calling this method always throws an SQLException.
Parameters:
pos - the position in the BLOB object at whichto start writing
Parameters:
bytes - the array of bytes to be written to the BLOBvalue that this Blob object represents the number of bytes written
exception:
SQLException - if there is an error accessing theBLOB value
See Also: jdbcBlob.getBytes
since:
JDK 1.4, HSQLDB 1.7.2 |
| setBytes | | public int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException(Code) | | 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.
HSQLDB-Specific Information:
HSLQDB 1.7.2 does not support this feature.
Calling this method always throws an SQLException.
Parameters:
pos - the position in the BLOB object at whichto start writing
Parameters:
bytes - the array of bytes to be written to this BLOBobject
Parameters:
offset - the offset into the array bytes at whichto start reading the bytes to be set
Parameters:
len - the number of bytes to be written to the BLOBvalue from the array of bytes bytes the number of bytes written
exception:
SQLException - if there is an error accessing theBLOB value
See Also: jdbcBlob.getBytes
since:
JDK 1.4, HSQLDB 1.7.2 |
| truncate | | public void truncate(long len) throws SQLException(Code) | | Truncates the BLOB value that this Blob
object represents to be len bytes in length.
HSQLDB-Specific Information:
This operation affects only the client-side value; it has no effect upon
the value as it is stored in the database.
Parameters:
len - the length, in bytes, to which the BLOB valuethat this Blob object represents should be truncated
exception:
SQLException - if there is an error accessing theBLOB value
since:
JDK 1.4, HSQLDB 1.7.2 |
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