com.oceanbase.jdbc

类 Blob

java.lang.Object

com.oceanbase.jdbc.Lob

com.oceanbase.jdbc.Blob

所有已实现的接口:

Serializable, Blob

public class Blob
extends Lob
implements Blob

另请参阅:

序列化表格

字段概要

从类继承的字段 com.oceanbase.jdbc.Lob

charData, data, DBMS_LOB_MAX_AMOUNT, encoding, exceptionInterceptor, isOracleMode, length, lengthFromServer, locator, offset

构造器概要

构造器

构造器和说明
Blob() Creates an empty blob.
Blob(Blob other)
Blob(boolean hasLocator, byte[] data, String encoding, OceanBaseConnection conn) Create a BLOB with Locator
Blob(byte[] bytes) Creates a blob with content.
Blob(byte[] bytes, ExceptionInterceptor exceptionInterceptor)
Blob(byte[] bytes, int offset, int length) Creates a blob with content.

方法概要

限定符和类型	方法和说明
Reader	getCharacterStream()
static Blob	getEmptyBLOB()
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 which pattern begins.
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.
protected void	readFromServer() Read Clob object by the DBMS_LOB.READ(lob_loc, amount, offset, buffer).
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.
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.
void	trimBlobToServer(int len) Truncate Blob object by the DBMS_LOB.trim(?
void	truncate(long len) Truncates the BLOB value that this Blob object represents to be len bytes in length.
void	updateBlobToServer(long writeAt, byte[] bytes, int offset, int length) Update Blob object by the DBMS_LOB.write(?

从类继承的方法 com.oceanbase.jdbc.Lob

buildObLobLocatorV1, buildObLobLocatorV2, clearData, copy, free, getBinaryStream, getBinaryStream, getBytes, getLocator, isEmptyLob, setBinaryStream

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 java.sql.Blob

free, getBinaryStream, getBinaryStream, getBytes, setBinaryStream

构造器详细资料

Blob

public Blob()

Creates an empty blob.

Blob

public Blob(Blob other)

Blob

public Blob(byte[] bytes)

Creates a blob with content.

参数:

bytes - the content for the blob.

Blob

public Blob(byte[] bytes,
            ExceptionInterceptor exceptionInterceptor)

Blob

public Blob(byte[] bytes,
            int offset,
            int length)

Creates a blob with content.

参数:

bytes - the content for the blob.

offset - offset

length - length

Blob

public Blob(boolean hasLocator,
            byte[] data,
            String encoding,
            OceanBaseConnection conn)
     throws SQLException

Create a BLOB with Locator

参数:

data -

抛出:

SQLException

方法详细资料

getEmptyBLOB

public static Blob getEmptyBLOB()
                         throws SQLException

抛出:

SQLException

length

public long length()

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

指定者:

length 在接口中 Blob

返回:

length of the BLOB in bytes

getCharacterStream

public Reader getCharacterStream()
                          throws SQLException

抛出:

SQLException

position

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

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.

指定者:

position 在接口中 Blob

参数:

pattern - the byte array for which to search

start - the position at which to begin searching; the first position is 1

返回:

the position at which the pattern appears, else -1

抛出:

SQLException

position

public long position(Blob pattern,
                     long start)
              throws SQLException

Retrieves the byte position in the BLOB value designated by this Blob object at which pattern begins. The search begins at position start.

指定者:

position 在接口中 Blob

参数:

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

返回:

the position at which the pattern begins, else -1

抛出:

SQLException

setBytes

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

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.

指定者:

setBytes 在接口中 Blob

覆盖:

setBytes 在类中 Lob

参数:

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

返回:

the number of bytes written

抛出:

SQLException

另请参阅:

Lob.getBytes(long, int)

setBytes

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

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.

指定者:

setBytes 在接口中 Blob

参数:

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

返回:

the number of bytes written

抛出:

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

另请参阅:

Lob.getBytes(long, int)

truncate

public void truncate(long len)
              throws SQLException

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

指定者:

truncate 在接口中 Blob

参数:

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

抛出:

SQLException

updateBlobToServer

public void updateBlobToServer(long writeAt,
                               byte[] bytes,
                               int offset,
                               int length)
                        throws SQLException

Update Blob object by the DBMS_LOB.write(?,?,?,?), starting with writeAt and write the bytes to database. DBMS_LOB.WRITE ( lob_loc IN OUT NOCOPY BLOB, amount IN INTEGER, offset IN INTEGER, buffer IN RAW); lob_loc: Locator for the internal LOB to be written to. For more information amount: Number of bytes (for BLOBs) or characters (for CLOBs) to write offset: Offset in bytes (for BLOBs) or characters (for CLOBs) from the start of the LOB (origin: 1) for the write operation. buffer: Input buffer for the write

参数:

writeAt - Start position to be write.

bytes - byte[] data to be write.

offset - first position offset will be write.

length - date length to be write.

抛出:

SQLException - if database error occur

trimBlobToServer

public void trimBlobToServer(int len)
                      throws SQLException

Truncate Blob object by the DBMS_LOB.trim(?,?), truncate data from len, exception if len is big than data's length and success when len is less than data's length.

参数:

len - truncate data from len

抛出:

SQLException - if database error occur

readFromServer

protected void readFromServer()
                       throws SQLException

Read Clob object by the DBMS_LOB.READ(lob_loc, amount, offset, buffer). DBMS_LOB.READ ( lob_loc IN BLOB, amount IN OUT NOCOPY INTEGER, offset IN INTEGER, buffer OUT RAW); lob_loc: Locator for the LOB to be read. For more information, see Operational Notes. amount: Number of bytes (for BLOBs) or characters (for CLOBs) to read, or number that were read. offset: Offset in bytes (for BLOBs) or characters (for CLOBs) from the start of the LOB (origin: 1). buffer: Output buffer for the read operation.

指定者:

readFromServer 在类中 Lob

抛出:

SQLException - if database READ procedure exceptions occur INVALID_ARGVAL: amount is less than 1, or amount is larger than 32767 bytes (or the character equivalent) offset is less than 1, or offset is larger than LOBMAXSIZE amount is greater, in bytes or characters, than the capacity of buffer. NO_DATA_FOUND: End of the LOB is reached, and there are no more bytes or characters to read from the LOB: amount has a value of 0.