com.sequoiadb.base

接口 DBLob

所有超级接口:

AutoCloseable, Closeable

public interface DBLob
extends Closeable

LOB of SequoiaDB.

字段概要

字段

限定符和类型	字段和说明
static int	SDB_LOB_READ LOB open mode for reading
static int	SDB_LOB_SEEK_CUR Change the position from the current position of lob
static int	SDB_LOB_SEEK_END Change the position from the end of lob
static int	SDB_LOB_SEEK_SET Change the position from the beginning of lob
static int	SDB_LOB_WRITE LOB open mode for writing

方法概要

限定符和类型	方法和说明
void	close() Close the lob.
long	getCreateTime() Get the create time of lob.
ObjectId	getID() Get the lob's id.
long	getModificationTime() Get the last modification time of lob.
long	getSize() Get the size of lob.
boolean	isEof() Check whether current offset has reached to the max size of the current lob.
void	lock(long offset, long length) Lock LOB section for write mode.
void	lockAndSeek(long offset, long length) Lock LOB section for write mode and seek to the offset position.
int	read(byte[] b) Read up to b.length bytes of data from this lob into an array of bytes.
int	read(byte[] b, int off, int len) Read up to len bytes of data from this lob into an array of bytes.
void	read(OutputStream out) Read the content to the output stream.
void	seek(long size, int seekType) Change the read or write position of the lob.
void	write(byte[] b) Write b.length bytes from the specified byte array to this lob.
void	write(byte[] b, int off, int len) Write len bytes from the specified byte array starting at offset off to this lob.
void	write(InputStream in) Write bytes from the input stream to this lob.

字段详细资料

SDB_LOB_READ

static final int SDB_LOB_READ

LOB open mode for reading

另请参阅:

常量字段值

SDB_LOB_SEEK_CUR

static final int SDB_LOB_SEEK_CUR

Change the position from the current position of lob

另请参阅:

常量字段值

SDB_LOB_SEEK_END

static final int SDB_LOB_SEEK_END

Change the position from the end of lob

另请参阅:

常量字段值

SDB_LOB_SEEK_SET

static final int SDB_LOB_SEEK_SET

Change the position from the beginning of lob

另请参阅:

常量字段值

SDB_LOB_WRITE

static final int SDB_LOB_WRITE

LOB open mode for writing

另请参阅:

常量字段值

方法详细资料

close

void close()
    throws BaseException

Close the lob.

指定者:

close 在接口中 AutoCloseable

指定者:

close 在接口中 Closeable

抛出:

BaseException - If error happens.

getCreateTime

long getCreateTime()

Get the create time of lob.

返回:

the lob's create time

getID

ObjectId getID()

Get the lob's id.

返回:

the lob's id

getModificationTime

long getModificationTime()

Get the last modification time of lob.

返回:

the lob's last modification time

getSize

long getSize()

Get the size of lob.

返回:

the lob's size

isEof

boolean isEof()

Check whether current offset has reached to the max size of the current lob.

返回:

Return true if yes while false for not.

lock

void lock(long offset,
          long length)
   throws BaseException

Lock LOB section for write mode.

参数:

offset - lock start position

length - lock length, -1 means lock to the end of lob

抛出:

BaseException - If error happens..

lockAndSeek

void lockAndSeek(long offset,
                 long length)
          throws BaseException

Lock LOB section for write mode and seek to the offset position.

参数:

offset - lock start position

length - lock length, -1 means lock to the end of lob

抛出:

BaseException - If error happens..

read

int read(byte[] b)
  throws BaseException

Read up to b.length bytes of data from this lob into an array of bytes.

参数:

b - the buffer into which the data is read.

返回:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached, or 0 if b.length is Zero.

抛出:

BaseException - If error happens.

read

int read(byte[] b,
         int off,
         int len)
  throws BaseException

Read up to len bytes of data from this lob into an array of bytes.

参数:

b - the buffer into which the data is read.

off - the start offset in the destination array b.

len - the maximum number of bytes read.

返回:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached, or 0 if len is Zero.

抛出:

BaseException - If error happens.

read

void read(OutputStream out)
   throws BaseException

Read the content to the output stream. user need to close the output stream.

参数:

out - the output stream.

抛出:

BaseException - If error happens.

seek

void seek(long size,
          int seekType)
   throws BaseException

Change the read or write position of the lob. The new position is obtained by adding size to the position specified by seekType. If seekType is set to SDB_LOB_SEEK_SET, SDB_LOB_SEEK_CUR, or SDB_LOB_SEEK_END, the offset is relative to the start of the lob, the current position of lob, or the end of lob.

参数:

size - the adding size.

seekType - SDB_LOB_SEEK_SET/SDB_LOB_SEEK_CUR/SDB_LOB_SEEK_END

抛出:

BaseException - If error happens..

write

void write(byte[] b)
    throws BaseException

Write b.length bytes from the specified byte array to this lob.

参数:

b - the data.

抛出:

BaseException - If error happens.

write

void write(byte[] b,
           int off,
           int len)
    throws BaseException

Write len bytes from the specified byte array starting at offset off to this lob.

参数:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

抛出:

BaseException - If error happens.

write

void write(InputStream in)
    throws BaseException

Write bytes from the input stream to this lob. user need to close the input stream

参数:

in - the input stream.

抛出:

BaseException - If error happens.