java.sql.Blob

public interface java.sql

Blob

Java SE 6

Implemented by: SerialBlob

The representation (mapping) in the Java^TM 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.

since 1.2

Methods

public void

free() throws SQLException Details

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.

Throws SQLException: if an error occurs releasing the Blob's resources

Throws SQLFeatureNotSupportedException: if the JDBC driver does not support this method

since 1.6

public long

length() throws SQLException Details

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

return	length of the `BLOB` in bytes
Throws	SQLException: if there is an error accessing the length of the `BLOB`
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.2

public long

position(byte[] pattern, long start) throws SQLException Details

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.

pattern	the byte array for which to search
start	the position at which to begin searching; the first position is 1
return	the position at which the pattern appears, else -1
Throws	SQLException: if there is an error accessing the `BLOB` or if start is less than 1
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.2

public long

position(Blob pattern, long start) throws SQLException Details

Retrieves the byte position in the 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 search
start	the position in the `BLOB` value at which to begin searching; the first position is 1
return	the position at which the pattern begins, else -1
Throws	SQLException: if there is an error accessing the `BLOB` value or if start is less than 1
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.2

public void

truncate(long len) throws SQLException Details

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.

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

Throws SQLException: if there is an error accessing the BLOB value or if len is less than 0

Throws SQLFeatureNotSupportedException: if the JDBC driver does not support this method

since 1.4

Properties

public OutputStream

setBinaryStream(long pos) throws SQLException Details

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.

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

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

Throws SQLException: if there is an error accessing the BLOB value or if pos is less than 1

Throws SQLFeatureNotSupportedException: if the JDBC driver does not support this method

since 1.4

See also getBinaryStream

public InputStream

getBinaryStream() throws SQLException Details

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

return	a stream containing the `BLOB` data
Throws	SQLException: if there is an error accessing the `BLOB` value
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.2
See also	setBinaryStream

public InputStream

getBinaryStream(long pos, long length) throws SQLException Details

Returns an 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 retrieved
return	`InputStream` through which the partial `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 `Blob` or if pos + length is greater than the number of bytes in the `Blob`
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.6

public int

setBytes(long pos, byte[] bytes) throws SQLException Details

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.

pos the position in the BLOB object at which to start writing; the first position is 1

bytes the array of bytes to be written to the BLOB value that this Blob object represents

return the number of bytes written

Throws SQLException: if there is an error accessing the BLOB value or if pos is less than 1

Throws SQLFeatureNotSupportedException: if the JDBC driver does not support this method

since 1.4

See also getBytes

public int

setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException Details

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.

pos the position in the BLOB object at which to start writing; the first position is 1

bytes the array of bytes to be written to this BLOB object

offset the offset into the array bytes at which to start reading the bytes to be set

len the number of bytes to be written to the BLOB value from the array of bytes bytes

return the number of bytes written

Throws SQLException: if there is an error accessing the BLOB value or if pos is less than 1

Throws SQLFeatureNotSupportedException: if the JDBC driver does not support this method

since 1.4

See also getBytes

public byte[]

getBytes(long pos, int length) throws SQLException Details

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.

pos	the ordinal position of the first byte in the `BLOB` value to be extracted; the first byte is at position 1
length	the number of consecutive bytes to be copied; the value for length must be 0 or greater
return	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`
Throws	SQLException: if there is an error accessing the `BLOB` value; if pos is less than 1 or length is less than 0
Throws	SQLFeatureNotSupportedException: if the JDBC driver does not support this method
since	1.2
See also	setBytes

About DocWeb · Bundles · Export · Export All

Top 10 · Statistics · Login

About Sun · Contact · Privacy · Terms of Use · Trademarks

Java SE 6