Added in API level 1

Blob

interface Blob

java.sql.Blob

The representation (mapping) in the JavaTM programming language of an SQL 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.

Summary

Public methods
abstract Unit	free() This method frees the Blob object and releases the resources that it holds.
abstract InputStream!	getBinaryStream() Retrieves the BLOB value designated by this Blob instance as a stream.
abstract InputStream!	getBinaryStream(pos: Long, length: Long) Returns an InputStream object that contains a partial Blob value, starting with the byte specified by pos, which is length bytes in length.
abstract ByteArray!	getBytes(pos: Long, length: Int) Retrieves all or part of the BLOB value that this Blob object represents, as an array of bytes.
abstract Long	length() Returns the number of bytes in the BLOB value designated by this Blob object.
abstract Long	position(pattern: ByteArray!, start: Long) Retrieves the byte position at which the specified byte array pattern begins within the BLOB value that this Blob object represents.
abstract Long	position(pattern: Blob!, start: Long) Retrieves the byte position in the BLOB value designated by this Blob object at which pattern begins.
abstract OutputStream!	setBinaryStream(pos: Long) Retrieves a stream that can be used to write to the BLOB value that this Blob object represents.
abstract Int	setBytes(pos: Long, bytes: ByteArray!) 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.
abstract Int	setBytes(pos: Long, bytes: ByteArray!, offset: Int, len: Int) 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.
abstract Unit	truncate(len: Long) Truncates the BLOB value that this Blob object represents to be len bytes in length.

Public methods

free

Added in API level 9

abstract fun free(): Unit

This method frees the 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 a SQLException being thrown. If free is called multiple times, the subsequent calls to free are treated as a no-op.

Exceptions
java.sql.SQLException	if an error occurs releasing the Blob's resources
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

getBinaryStream

Added in API level 1

abstract fun getBinaryStream(): InputStream!

Retrieves the BLOB value designated by this Blob instance as a stream.

Return
InputStream!	a stream containing the BLOB data

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

See Also

• #setBinaryStream

getBinaryStream

Added in API level 9

abstract fun getBinaryStream(
    pos: Long, 
    length: Long
): InputStream!

Returns an InputStream object that contains a partial Blob value, starting with the byte specified by pos, which is length bytes in length.

Parameters
pos	Long: the offset to the first byte of the partial value to be retrieved. The first byte in the Blob is at position 1
length	Long: the length in bytes of the partial value to be retrieved

Return
InputStream!	InputStream through which the partial Blob value can be read.

Exceptions
java.sql.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
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

getBytes

Added in API level 1

abstract fun getBytes(
    pos: Long, 
    length: Int
): ByteArray!

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.

Parameters
pos	Long: the ordinal position of the first byte in the BLOB value to be extracted; the first byte is at position 1
length	Int: the number of consecutive bytes to be copied; the value for length must be 0 or greater

Return
ByteArray!	a byte array containing up to length consecutive bytes from the BLOB value designated by this Blob object, starting with the byte at position pos

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value; if pos is less than 1 or length is less than 0
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

See Also

length

Added in API level 1

abstract fun length(): Long

Returns the number of bytes in the BLOB value designated by this Blob object.

Return
Long	length of the BLOB in bytes

Exceptions
java.sql.SQLException	if there is an error accessing the length of the BLOB
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

position

Added in API level 1

abstract fun position(
    pattern: ByteArray!, 
    start: Long
): Long

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	ByteArray!: the byte array for which to search
start	Long: the position at which to begin searching; the first position is 1

Return
Long	the position at which the pattern appears, else -1

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB or if start is less than 1
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

position

Added in API level 1

abstract fun position(
    pattern: Blob!, 
    start: Long
): Long

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	Blob!: the Blob object designating the BLOB value for which to search
start	Long: the position in the BLOB value at which to begin searching; the first position is 1

Return
Long	the position at which the pattern begins, else -1

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value or if start is less than 1
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

setBinaryStream

Added in API level 1

abstract fun setBinaryStream(pos: Long): OutputStream!

Retrieves a stream that can be used to write to the 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 accomodate the extra bytes.

Note: If the value specified for pos is greater then the length+1 of the BLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.

Parameters
pos	Long: the position in the BLOB value at which to start writing; the first position is 1

Return
OutputStream!	a java.io.OutputStream object to which data can be written

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value or if pos is less than 1
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

See Also

setBytes

Added in API level 1

abstract fun setBytes(
    pos: Long, 
    bytes: ByteArray!
): Int

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. 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 accomodate the extra bytes.

Note: If the value specified for pos is greater then the length+1 of the BLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.

Parameters
pos	Long: the position in the BLOB object at which to start writing; the first position is 1
bytes	ByteArray!: the array of bytes to be written to the BLOB value that this Blob object represents

Return
Int	the number of bytes written

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value or if pos is less than 1
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

See Also

• #getBytes

setBytes

Added in API level 1

abstract fun setBytes(
    pos: Long, 
    bytes: ByteArray!, 
    offset: Int, 
    len: Int
): Int

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. 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 accomodate the extra bytes.

Note: If the value specified for pos is greater then the length+1 of the BLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.

Parameters
pos	Long: the position in the BLOB object at which to start writing; the first position is 1
bytes	ByteArray!: the array of bytes to be written to this BLOB object
offset	Int: the offset into the array bytes at which to start reading the bytes to be set
len	Int: the number of bytes to be written to the BLOB value from the array of bytes bytes

Return
Int	the number of bytes written

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value or if pos is less than 1
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method

See Also

• #getBytes

truncate

Added in API level 1

abstract fun truncate(len: Long): Unit

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

Note: If the value specified for pos is greater then the length+1 of the BLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.

Parameters
len	Long: the length, in bytes, to which the BLOB value that this Blob object represents should be truncated

Exceptions
java.sql.SQLException	if there is an error accessing the BLOB value or if len is less than 0
java.sql.SQLFeatureNotSupportedException	if the JDBC driver does not support this method