Added in API level 1

Blob

public interface Blob

java.sql.Blob

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.

Summary

Public methods
`abstract void`	`free()` This method frees the `Blob` object and releases the resources that it holds.
`abstract InputStream`	`getBinaryStream(long pos, long length)` Returns an `InputStream` object that contains a partial `Blob` value, starting with the byte specified by pos, which is length bytes in length.
`abstract InputStream`	`getBinaryStream()` Retrieves the `BLOB` value designated by this `Blob` instance as a stream.
`abstract byte[]`	`getBytes(long pos, int length)` 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(Blob pattern, long start)` Retrieves the byte position in the `BLOB` value designated by this `Blob` object at which `pattern` begins.
`abstract 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.
`abstract OutputStream`	`setBinaryStream(long pos)` Retrieves a stream that can be used to write to the `BLOB` value that this `Blob` object represents.
`abstract 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.
`abstract 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.
`abstract void`	`truncate(long len)` Truncates the `BLOB` value that this `Blob` object represents to be `len` bytes in length.

Public methods

free

Added in API level 9

public abstract void free ()

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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

getBinaryStream

Added in API level 9

public abstract InputStream getBinaryStream (long pos, 
                long length)

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

Returns
`InputStream`	`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`
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

getBinaryStream

Added in API level 1

public abstract InputStream getBinaryStream ()

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

Returns
`InputStream`	a stream containing the `BLOB` data

Throws
`SQLException`	if there is an error accessing the `BLOB` value
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

See also:

setBinaryStream(long)

getBytes

Added in API level 1

public abstract byte[] getBytes (long pos, 
                int length)

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

Returns
`byte[]`	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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

See also:

setBytes(long, byte)

length

Added in API level 1

public abstract long length ()

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

Returns
`long`	length of the `BLOB` in bytes

Throws
`SQLException`	if there is an error accessing the length of the `BLOB`
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

position

Added in API level 1

public abstract long position (Blob pattern, 
                long start)

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

Returns
`long`	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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

position

Added in API level 1

public abstract 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. The search for pattern begins at position start.

Parameters
`pattern`	`byte`: the byte array for which to search
`start`	`long`: the position at which to begin searching; the first position is 1

Returns
`long`	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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

setBinaryStream

Added in API level 1

public abstract OutputStream setBinaryStream (long pos)

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

Returns
`OutputStream`	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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

See also:

getBinaryStream()

setBytes

Added in API level 1

public abstract 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. 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.

Parameters
`pos`	`long`: the position in the `BLOB` object at which to start writing; the first position is 1
`bytes`	`byte`: 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`

Returns
`int`	the number of bytes written

Throws
`SQLException`	if there is an error accessing the `BLOB` value or if pos is less than 1
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

See also:

getBytes(long, int)

setBytes

Added in API level 1

public abstract 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. 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.

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

Returns
`int`	the number of bytes written

Throws
`SQLException`	if there is an error accessing the `BLOB` value or if pos is less than 1
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method

See also:

getBytes(long, int)

truncate

Added in API level 1

public abstract void truncate (long len)

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

Parameters
`len`	`long`: 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
`SQLFeatureNotSupportedException`	if the JDBC driver does not support this method