UpdateSensitiveLOBLocatorInputStream (Apache Derby V10.14 Internals)

java.lang.Object
- java.io.InputStream
- - org.apache.derby.client.am.UpdateSensitiveLOBLocatorInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

UpdateSensitiveBlobLocatorInputStream, UpdateSensitiveClobLocatorInputStream
```
abstract class UpdateSensitiveLOBLocatorInputStream
extends java.io.InputStream
```
Super-class of the Update sensitive locator streams. Before a read operation if performed on the stream this stream verifies that the underlying LOB has not changed and if it has it recreates the specific streams. Since Locator streams are specific to Blob and Clob the sub-classes would take care of creating the appropriate streams.

Field Summary

Fields
Modifier and Type	Field	Description
`protected ClientConnection`	`con`
`protected long`	`currentPos`
`private java.io.BufferedInputStream`	`is`
`protected long`	`length`
`private Lob`	`lob`
`private long`	`updateCount`

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`UpdateSensitiveLOBLocatorInputStream(ClientConnection con, Lob lob, java.io.InputStream is)`	Initializes the InputStream, updateCount, currentPos and the connection to the appropriate values.
`protected`	`UpdateSensitiveLOBLocatorInputStream(ClientConnection con, Lob lob, java.io.InputStream is, long pos, long len)`	Initializes the InputStream, updateCount, currentPos, length and the connection to the appropriate values.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`
`private void`	`identifyAndReplaceObseleteStream()`	Verifies whether the current updateCount matches the updateCount of the LOB object and if it does not it recreates the stream.
`int`	`read()`
`int`	`read(byte[] b, int off, int len)`
`protected abstract java.io.InputStream`	`reCreateStream()`	Abstract method that will be implemented by the underlying streams specific to Clob and Blob.

Methods inherited from class java.io.InputStream
available, mark, markSupported, read, readAllBytes, readNBytes, reset, skip, transferTo

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - is
```
private java.io.BufferedInputStream is
```
  - con
```
protected ClientConnection con
```
  - lob
```
private Lob lob
```
  - updateCount
```
private long updateCount
```
  - currentPos
```
protected long currentPos
```
  - length
```
protected long length
```
- Constructor Detail
  - UpdateSensitiveLOBLocatorInputStream
```
protected UpdateSensitiveLOBLocatorInputStream(ClientConnection con,
                                               Lob lob,
                                               java.io.InputStream is)
                                        throws SqlException
```
    Initializes the InputStream, updateCount, currentPos and the connection to the appropriate values.
    
    Parameters:
    
    con - connection to be used to read the Lob value from the server
    
    lob - Lob object which could be a Blob or a Clob.
    
    is - an InputStream that contains the appropriate locator stream instance.
    
    Throws:
    
    SqlException
  - UpdateSensitiveLOBLocatorInputStream
```
protected UpdateSensitiveLOBLocatorInputStream(ClientConnection con,
                                               Lob lob,
                                               java.io.InputStream is,
                                               long pos,
                                               long len)
                                        throws SqlException
```
    Initializes the InputStream, updateCount, currentPos, length and the connection to the appropriate values.
    
    Parameters:
    
    con - connection to be used to read the Lob value from the server
    
    lob - Lob object which could be a Blob or a Clob.
    
    is - an InputStream that contains the appropriate locator stream instance.
    
    pos - the position from which the first read begins.
    
    len - the length in bytes of the partial value to be retrieved.
    
    Throws:
    
    SqlException
- Method Detail
  - read
```
public int read()
         throws java.io.IOException
```
    Specified by:
    
    read in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
    
    See Also:
    
    InputStream.read()
  - read
```
public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
```
    Overrides:
    
    read in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
    
    See Also:
    
    InputStream.read(byte[], int, int)
  - close
```
public void close()
           throws java.io.IOException
```
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Overrides:
    
    close in class java.io.InputStream
    
    Throws:
    
    java.io.IOException
  - identifyAndReplaceObseleteStream
```
private void identifyAndReplaceObseleteStream()
                                       throws java.io.IOException
```
    Verifies whether the current updateCount matches the updateCount of the LOB object and if it does not it recreates the stream.
    
    Throws:
    
    java.io.IOException - If any exception occurs upon Locator stream creation.
  - reCreateStream
```
protected abstract java.io.InputStream reCreateStream()
                                               throws SqlException
```
    Abstract method that will be implemented by the underlying streams specific to Clob and Blob.
    
    Throws:
    
    SqlException

Class UpdateSensitiveLOBLocatorInputStream

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.io.InputStream

Methods inherited from class java.lang.Object

Field Detail

is

con

lob

updateCount

currentPos

length

Constructor Detail

UpdateSensitiveLOBLocatorInputStream

UpdateSensitiveLOBLocatorInputStream

Method Detail

read

read

close

identifyAndReplaceObseleteStream

reCreateStream