SerialBlob
public interface Blob
BLOB
value. An SQL BLOB
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 Blob
using an SQL locator(BLOB)
, which means that a Blob
object contains a logical pointer to the SQL BLOB
data rather than the data itself. A Blob
object is valid for the duration of the transaction in which is was created. Methods in the interfaces ResultSet
, CallableStatement
, and PreparedStatement
, such as getBlob
and setBlob
allow a programmer to access an SQL BLOB
value. The Blob
interface 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 a pattern of bytes within a BLOB
value. In addition, this interface has methods for updating a BLOB
value.
All methods on the Blob
interface must be fully implemented if the JDBC driver supports the data type.
Modifier and Type | Method | Description |
---|---|---|
void |
free() |
This method frees the Blob object and releases the resources that it holds. |
InputStream |
getBinaryStream() |
Retrieves the BLOB value designated by this Blob instance as a stream. |
InputStream |
getBinaryStream |
Returns an InputStream object that contains a partial Blob value, starting with the byte specified by pos, which is length bytes in length. |
byte[] |
getBytes |
Retrieves all or part of the BLOB value that this Blob object represents, as an array of bytes. |
long |
length() |
Returns the number of bytes in the BLOB value designated by this Blob object. |
long |
position |
Retrieves the byte position at which the specified byte array pattern begins within the BLOB value that this Blob object represents. |
long |
position |
Retrieves the byte position in the BLOB value designated by this Blob object at which pattern begins. |
OutputStream |
setBinaryStream |
Retrieves a stream that can be used to write to the BLOB value that this Blob object represents. |
int |
setBytes |
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. |
int |
setBytes |
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. |
void |
truncate |
Truncates the BLOB value that this Blob object represents to be len bytes in length. |
long length() throws SQLException
BLOB
value designated by this Blob
object.BLOB
in bytesSQLException
- if there is an error accessing the length of the BLOB
SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodbyte[] getBytes(long pos, int length) throws SQLException
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
.pos
- the ordinal position of the first byte in the BLOB
value to be extracted; the first byte is at position 1length
- the number of consecutive bytes to be copied; the value for length must be 0 or greaterlength
consecutive bytes from the BLOB
value designated by this Blob
object, starting with the byte at position pos
SQLException
- if there is an error accessing the BLOB
value; if pos is less than 1 or length is less than 0SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodInputStream getBinaryStream() throws SQLException
BLOB
value designated by this Blob
instance as a stream.BLOB
dataSQLException
- if there is an error accessing the BLOB
valueSQLFeatureNotSupportedException
- if the JDBC driver does not support this methodlong position(byte[] pattern, long start) throws SQLException
pattern
begins within the BLOB
value that this Blob
object represents. The search for pattern
begins at position start
.pattern
- the byte array for which to searchstart
- the position at which to begin searching; the first position is 1SQLException
- if there is an error accessing the BLOB
or if start is less than 1SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodlong position(Blob pattern, long start) throws SQLException
BLOB
value designated by this Blob
object at which pattern
begins. The search begins at position start
.pattern
- the Blob
object designating the BLOB
value for which to searchstart
- the position in the BLOB
value at which to begin searching; the first position is 1SQLException
- if there is an error accessing the BLOB
value or if start is less than 1SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodint setBytes(long pos, byte[] bytes) throws SQLException
BLOB
value that this Blob
object represents, starting at position pos
, and returns the number of bytes written. The array of bytes will overwrite the existing bytes in the Blob
object starting at the position pos
. If the end of the Blob
value is reached while writing the array of bytes, then the length of the Blob
value will be increased to accommodate the extra bytes. Note: If the value specified for pos
is greater than the length+1 of the BLOB
value then the behavior is undefined. Some JDBC drivers may throw an SQLException
while other drivers may support this operation.
pos
- the position in the BLOB
object at which to start writing; the first position is 1bytes
- the array of bytes to be written to the BLOB
value that this Blob
object representsSQLException
- if there is an error accessing the BLOB
value or if pos is less than 1SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodint setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException
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. The array of bytes will overwrite the existing bytes in the Blob
object starting at the position pos
. If the end of the Blob
value is reached while writing the array of bytes, then the length of the Blob
value will be increased to accommodate the extra bytes. Note: If the value specified for pos
is greater than the length+1 of the BLOB
value then the behavior is undefined. Some JDBC drivers may throw an SQLException
while other drivers may support this operation.
pos
- the position in the BLOB
object at which to start writing; the first position is 1bytes
- the array of bytes to be written to this BLOB
objectoffset
- the offset into the array bytes
at which to start reading the bytes to be setlen
- the number of bytes to be written to the BLOB
value from the array of bytes bytes
SQLException
- if there is an error accessing the BLOB
value or if pos is less than 1SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodOutputStream setBinaryStream(long pos) throws SQLException
BLOB
value that this Blob
object represents. The stream begins at position pos
. The bytes written to the stream will overwrite the existing bytes in the Blob
object starting at the position pos
. If the end of the Blob
value is reached while writing to the stream, then the length of the Blob
value will be increased to accommodate the extra bytes. Note: If the value specified for pos
is greater than the length+1 of the BLOB
value then the behavior is undefined. Some JDBC drivers may throw an SQLException
while other drivers may support this operation.
pos
- the position in the BLOB
value at which to start writing; the first position is 1java.io.OutputStream
object to which data can be writtenSQLException
- if there is an error accessing the BLOB
value or if pos is less than 1SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodvoid truncate(long len) throws SQLException
BLOB
value that this Blob
object represents to be len
bytes in length. Note: If the value specified for pos
is greater than the length+1 of the BLOB
value then the behavior is undefined. Some JDBC drivers may throw an SQLException
while other drivers may support this operation.
len
- the length, in bytes, to which the BLOB
value that this Blob
object represents should be truncatedSQLException
- if there is an error accessing the BLOB
value or if len is less than 0SQLFeatureNotSupportedException
- if the JDBC driver does not support this methodvoid free() throws SQLException
Blob
object and releases the resources that it holds. The object is invalid once the free
method is called. After free
has been called, any attempt to invoke a method other than free
will result in an SQLException
being thrown. If free
is called multiple times, the subsequent calls to free
are treated as a no-op.
SQLException
- if an error occurs releasing the Blob's resourcesSQLFeatureNotSupportedException
- if the JDBC driver does not support this methodInputStream getBinaryStream(long pos, long length) throws SQLException
InputStream
object that contains a partial Blob
value, starting with the byte specified by pos, which is length bytes in length.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 retrievedInputStream
through which the partial Blob
value can be read.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
SQLFeatureNotSupportedException
- if the JDBC driver does not support this method
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Documentation extracted from Debian's OpenJDK Development Kit package.
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