Blob (Java Platform SE 8 ) (original) (raw)

All Known Implementing Classes:
SerialBlob

public interface Blob
The representation (mapping) in the Java™ programming language of an SQLBLOB 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 aBlob 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 asgetBlob 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 aBLOB 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

Method Summary

All Methods Instance Methods Abstract Methods

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 thisBlob instance as a stream.
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.
byte[]	getBytes(long pos, int length)	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(Blob pattern, long start)	Retrieves the byte position in the BLOB value designated by this Blob object at whichpattern begins.
long	position(byte[] pattern, long start)	Retrieves the byte position at which the specified byte arraypattern begins within the BLOB value that this Blob object represents.
OutputStream	setBinaryStream(long pos)	Retrieves a stream that can be used to write to the BLOB value that this Blob object represents.
int	setBytes(long pos, byte[] bytes)	Writes the given array of bytes to the BLOB value that this Blob object represents, starting at positionpos, and returns the number of bytes written.
int	setBytes(long pos, byte[] bytes, int offset, int len)	Writes all or part of the given byte array to theBLOB value that this Blob object represents and returns the number of bytes written.
void	truncate(long len)	Truncates the BLOB value that this Blob object represents to be len bytes in length.

Method Detail

 * #### length  
 long length()  
      throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 Returns the number of bytes in the `BLOB` value designated by this `Blob` object.  
 Returns:  
 length of the `BLOB` in bytes  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the length of the `BLOB`  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.2  
 * #### getBytes  
 byte[] getBytes(long pos,  
                 int length)  
          throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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` \- 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  
 Returns:  
 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](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value; if pos is less than 1 or length is less than 0  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.2  
 See Also:  
 [setBytes(long, byte\[\])](../../java/sql/Blob.html#setBytes-long-byte:A-)  
 * #### getBinaryStream  
 [InputStream](../../java/io/InputStream.html "class in java.io") getBinaryStream()  
                      throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 Retrieves the `BLOB` value designated by this`Blob` instance as a stream.  
 Returns:  
 a stream containing the `BLOB` data  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.2  
 See Also:  
 [setBinaryStream(long)](../../java/sql/Blob.html#setBinaryStream-long-)  
 * #### position  
 long position(byte[] pattern,  
               long start)  
        throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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  
 `start` \- the position at which to begin searching; the first position is 1  
 Returns:  
 the position at which the pattern appears, else -1  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` or if start is less than 1  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.2  
 * #### position  
 long position([Blob](../../java/sql/Blob.html "interface in java.sql") pattern,  
               long start)  
        throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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 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  
 Returns:  
 the position at which the pattern begins, else -1  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value or if start is less than 1  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.2  
 * #### setBytes  
 int setBytes(long pos,  
              byte[] bytes)  
       throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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 accommodate 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` \- 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  
 Returns:  
 the number of bytes written  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value or if pos is less than 1  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.4  
 See Also:  
 [getBytes(long, int)](../../java/sql/Blob.html#getBytes-long-int-)  
 * #### setBytes  
 int setBytes(long pos,  
              byte[] bytes,  
              int offset,  
              int len)  
       throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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 accommodate 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` \- 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`  
 Returns:  
 the number of bytes written  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value or if pos is less than 1  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.4  
 See Also:  
 [getBytes(long, int)](../../java/sql/Blob.html#getBytes-long-int-)  
 * #### setBinaryStream  
 [OutputStream](../../java/io/OutputStream.html "class in java.io") setBinaryStream(long pos)  
                       throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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 accommodate 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` \- the position in the `BLOB` value at which to start writing; the first position is 1  
 Returns:  
 a `java.io.OutputStream` object to which data can be written  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value or if pos is less than 1  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.4  
 See Also:  
 [getBinaryStream()](../../java/sql/Blob.html#getBinaryStream--)  
 * #### truncate  
 void truncate(long len)  
        throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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` \- the length, in bytes, to which the `BLOB` value that this `Blob` object represents should be truncated  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- if there is an error accessing the`BLOB` value or if len is less than 0  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.4  
 * #### free  
 void free()  
    throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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](../../java/sql/SQLException.html "class in java.sql")` \- if an error occurs releasing the Blob's resources  
 `[SQLFeatureNotSupportedException](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.6  
 * #### getBinaryStream  
 [InputStream](../../java/io/InputStream.html "class in java.io") getBinaryStream(long pos,  
                             long length)  
                      throws [SQLException](../../java/sql/SQLException.html "class in java.sql")  
 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` \- 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  
 Returns:  
 `InputStream` through which the partial `Blob` value can be read.  
 Throws:  
 `[SQLException](../../java/sql/SQLException.html "class in java.sql")` \- 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](../../java/sql/SQLFeatureNotSupportedException.html "class in java.sql")` \- if the JDBC driver does not support this method  
 Since:  
 1.6

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Blob (Java Platform SE 8 ) (original) (raw)

Method Summary

Method Detail