uk.org.ogsadai.client.toolkit.activity.delivery
Class DataTransportBlockReader
java.lang.Object
|
+--uk.org.ogsadai.client.toolkit.activity.delivery.DataTransportBlockReader
- All Implemented Interfaces:
- BlockReader
- public class DataTransportBlockReader
- extends java.lang.Object
- implements BlockReader
A BlockReader implementation which fetches each block from an output stream exposed by a data service resource exposed by a data service using the service's get operations.
- Author:
- The OGSA-DAI Project Team
| Field Summary |
private static java.lang.String |
COPYRIGHT_NOTICE
Copyright statement |
private int |
mBlocksToFetch
The number of blocks to fetch from a service at once. |
private java.lang.Object |
mNextBlock
The block which will be returned the next time the next method is called. |
private DataTransport |
mService
Object that handles get operations on a service. |
| Method Summary |
java.lang.Object |
fetchBlock()
Obtain a block from the output stream exposed by a data service resource of the service or return null if all the data has been read. |
boolean |
hasNext()
Indicates whether or not there are any more blocks of data to be read from the block reader. |
java.lang.Object |
next()
Gets the next block of data contained in the block reader. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
COPYRIGHT_NOTICE
private static final java.lang.String COPYRIGHT_NOTICE
-
Copyright statement
- See Also:
- Constant Field Values
mNextBlock
private java.lang.Object mNextBlock
-
The block which will be returned the next time the
next method is called. (We employ a one-block buffer to enable hasNext() to work.)
mBlocksToFetch
private final int mBlocksToFetch
-
The number of blocks to fetch from a service at once.
mService
private final DataTransport mService
-
Object that handles
get operations on a service.
DataTransportBlockReader
public DataTransportBlockReader(DataTransport service)
throws StreamDataException
DataTransportBlockReader
public DataTransportBlockReader(DataTransport service,
int blocksToFetch)
throws StreamDataException
-
Default constructor. Fetches the first block of data from an output stream exposed by a data service resource exposed by a data service and buffers this locally.
- Parameters:
service - Object handling access to the service's output stream.blocksToFetch - The number of blocks to fetch from the service at once. These are aggregated into a single block service-side.- Throws:
StreamDataException - If there is a problem when streaming the data from the service.
hasNext
public boolean hasNext()
- Description copied from interface:
BlockReader
-
Indicates whether or not there are any more blocks of data to be read from the block reader.
-
- Specified by:
hasNext in interface BlockReader
-
- Returns:
- true if there are more blocks to be read or false otherwise
next
public java.lang.Object next()
- Description copied from interface:
BlockReader
-
Gets the next block of data contained in the block reader.
-
- Specified by:
next in interface BlockReader
-
- Returns:
- an
Object
fetchBlock
public java.lang.Object fetchBlock()
throws StreamDataException
-
Obtain a block from the output stream exposed by a data service resource of the service or return
null if all the data has been read.
-
-
- Returns:
- block
- Throws:
StreamDataException - If there is a problem when streaming the data from the service.