java.io.Closeable
, java.lang.AutoCloseable
class BlobLocatorInputStream
extends java.io.InputStream
InputStream
that will use an locator to fetch the
Blob value from the server.
Closing a ByteArrayInputStream
has no effect. The methods in
this class can be called after the stream has been closed without
generating an IOException
.
This InputStream
implementation is pretty basic. No
buffering of data is done. Hence, for efficiency #read(byte[])
should be used instead of #read(). Marks are not supported, but it
should be pretty simple to extend the implementation to support
this. A more efficient skip implementation should also be
straight-forward.
Modifier and Type | Field | Description |
---|---|---|
private ClientBlob |
blob |
The Blob to be accessed.
|
private ClientConnection |
connection |
Connection used to read Blob from server.
|
private long |
currentPos |
Current position in the underlying Blob.
|
private long |
maxPos |
Position in Blob where to stop reading.
|
Constructor | Description |
---|---|
BlobLocatorInputStream(ClientConnection connection,
ClientBlob blob) |
Create an
InputStream for reading the
Blob value represented by the given locator based
Blob object. |
BlobLocatorInputStream(ClientConnection connection,
ClientBlob blob,
long position,
long length) |
Create an
InputStream for reading the
Blob value represented by the given locator based
Blob object. |
Modifier and Type | Method | Description |
---|---|---|
int |
read() |
|
int |
read(byte[] b,
int off,
int len) |
|
private byte[] |
readBytes(int len) |
Read the next
len bytes of the Blob
value from the server. |
private final ClientConnection connection
private final ClientBlob blob
private long currentPos
private final long maxPos
BlobLocatorInputStream(ClientConnection connection, ClientBlob blob) throws SqlException
InputStream
for reading the
Blob
value represented by the given locator based
Blob
object.connection
- connection to be used to read the
Blob
value from the serverblob
- Blob
object that contains locator for
the Blob
value on the server.SqlException
- if an error occurs when obtaining the
length of the Blob
.BlobLocatorInputStream(ClientConnection connection, ClientBlob blob, long position, long length) throws SqlException
InputStream
for reading the
Blob
value represented by the given locator based
Blob
object.connection
- connection to be used to read the
Blob
value from the serverblob
- Blob
object that contains locator for
the Blob
value on the server.position
- the position in the Blob
of the first
byte to read.length
- the maximum number of bytes to read from
the Blob
.SqlException
- if an error occurs when obtaining the
length of the Blob
.public int read() throws java.io.IOException
read
in class java.io.InputStream
java.io.IOException
This method fetches one byte at a time from the server. For more
efficient retrieval, use #read(byte[]).
public int read(byte[] b, int off, int len) throws java.io.IOException
read
in class java.io.InputStream
java.io.IOException
InputStream.read(byte[], int, int)
private byte[] readBytes(int len) throws java.io.IOException
len
bytes of the Blob
value from the server.len
- number of bytes to readbyte[]
containing the read bytesjava.io.IOException
- Wrapped SqlException if reading
from server fails.Apache Derby V10.14 Internals - Copyright © 2004,2018 The Apache Software Foundation. All Rights Reserved.