LOBFile (Apache Derby V10.14 Internals)

java.lang.Object
- 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

Fields
Modifier and Type	Field	Description
`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

Constructors
Constructor Description

LOBFile(StorageFile lobFile)
Constructs LOBFile.

Constructors
Constructor	Description
`LOBFile(StorageFile lobFile)`	Constructs LOBFile.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(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

Class LOBFile

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

storageFile

randomAccessFile

Constructor Detail

LOBFile

Method Detail

getStorageFile

length

seek

write

getFilePointer

write

readByte

read

close

setLength

write