org.apache.derby.impl.jdbc
Class LOBFile

java.lang.Object
  extended by org.apache.derby.impl.jdbc.LOBFile
Direct Known Subclasses:
EncryptedLOBFile

 class LOBFile
extends java.lang.Object

LOBFile is a wrapper over StorageRandomAccessFile. The purpose of this class is to let the user of this class access StorageRandomAccessFile in plain and in encrypted for without having to change code.


Field Summary
private  StorageRandomAccessFile randomAccessFile
          An object giving random access to storageFile.
private  StorageFile storageFile
          The temporary file where the contents of the LOB should be stored.
 
Constructor Summary
LOBFile(StorageFile lobFile)
          Constructs LOBFile.
 
Method Summary
(package private)  void close()
          Closes the file.
(package private)  long getFilePointer()
          Returns the current position of the file pointer.
(package private)  StorageFile getStorageFile()
          Get the StorageFile which represents the file where the contents of the LOB are stored.
(package private)  long length()
          Returns length of the file.
(package private)  int read(byte[] buff, int off, int len)
          Reads len number of bytes from the file starting from off position in the buffer.
(package private)  int readByte()
          Reads one byte from file.
(package private)  void seek(long pos)
          Sets the file pointer to a given position.
(package private)  void setLength(long size)
          Sets the file length to a given size.
(package private)  void write(byte[] buf)
          Writes a buffer completely into the file.
(package private)  void write(byte[] b, int off, int len)
          Writes a segment of bytes into the file.
(package private)  void write(int b)
          Writes one bytes into the file.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

storageFile

private final StorageFile storageFile
The temporary file where the contents of the LOB should be stored.


randomAccessFile

private final StorageRandomAccessFile randomAccessFile
An object giving random access to storageFile.

Constructor Detail

LOBFile

LOBFile(StorageFile lobFile)
  throws java.io.FileNotFoundException
Constructs LOBFile.

Parameters:
lobFile - StorageFile object for which the file will be created
Throws:
java.io.FileNotFoundException - if the file exists but is a directory or cannot be opened
Method Detail

getStorageFile

StorageFile getStorageFile()
Get the StorageFile which represents the file where the contents of the LOB are stored.

Returns:
a StorageFile instance

length

long length()
      throws java.io.IOException
Returns length of the file.

Returns:
length of the file
Throws:
java.io.IOException - if an I/O error occurs

seek

void seek(long pos)
    throws java.io.IOException
Sets the file pointer to a given position.

Parameters:
pos - new position
Throws:
java.io.IOException - if an I/O error occurs

write

void write(int b)
     throws java.io.IOException,
            StandardException
Writes one bytes into the file.

Parameters:
b - int value of the byte
Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

getFilePointer

long getFilePointer()
              throws java.io.IOException
Returns the current position of the file pointer.

Returns:
file pointer
Throws:
java.io.IOException - if an I/O error occurs

write

void write(byte[] b,
           int off,
           int len)
     throws java.io.IOException,
            StandardException
Writes a segment of bytes into the file.

Parameters:
b - byte array containing bytes to write into the file
off - starting position of segment
len - number of bytes to be written
Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

readByte

int readByte()
       throws java.io.IOException,
              StandardException
Reads one byte from file.

Returns:
byte
Throws:
java.io.IOException - if disk operation fails
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

read

int read(byte[] buff,
         int off,
         int len)
   throws java.io.IOException,
          StandardException
Reads len number of bytes from the file starting from off position in the buffer.

Parameters:
buff - buffer
off - starting position of buffer
len - number of bytes
Returns:
number of bytes read
Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

close

void close()
     throws java.io.IOException
Closes the file.

Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

setLength

void setLength(long size)
         throws java.io.IOException,
                StandardException
Sets the file length to a given size.

Parameters:
size - new size
Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

write

void write(byte[] buf)
     throws java.io.IOException,
            StandardException
Writes a buffer completely into the file.

Parameters:
buf - buffer to write
Throws:
java.io.IOException - if an I/O error occurs
StandardException - it won't be thrown, it's in signature to allow subclasses to throw StandardException

Built on Thu 2010-12-23 20:49:13+0000, from revision ???

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