com.bigdata.service
Class ResourceService.ReadResourceTask

java.lang.Object
  com.bigdata.service.ResourceService.FetchResourceTask<UUID,File>
      com.bigdata.service.ResourceService.ReadResourceTask

All Implemented Interfaces:

Callable<File>

Enclosing class:

ResourceService

public static class ResourceService.ReadResourceTask
extends ResourceService.FetchResourceTask<UUID,File>

Task sends a request for a file's data and then receives the data onto a local file.

TODO:

Receive file's data using NIO to transfer from a FileChannel to the caller using a SocketChannel.

Field Summary

protected static org.apache.log4j.Logger

log

Constructor Summary

ResourceService.ReadResourceTask(InetSocketAddress addr, UUID uuid, File file)

Method Summary

File	call() Return the File on which the resource was written.
UUID	logId() The logical identifier for the resource.
File	logResource() The resource.

Methods inherited from class com.bigdata.service.ResourceService.FetchResourceTask

transfer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

protected static final org.apache.log4j.Logger log

Constructor Detail

ResourceService.ReadResourceTask

public ResourceService.ReadResourceTask(InetSocketAddress addr,
                                        UUID uuid,
                                        File file)

Parameters:

addr - The Internet address and port at which the service from which the resource will be read is accepting connections.

port - The port at which to connect to the service from which the resource will be read.

uuid - The UUID which identifies the desired resource.

file - The local file on which the received data will be written. The file may exist but if it exists then it must be empty.

Method Detail

logId

public UUID logId()

Description copied from class: ResourceService.FetchResourceTask

The logical identifier for the resource.

logResource

public File logResource()

Description copied from class: ResourceService.FetchResourceTask

The resource.

call

public File call()
          throws Exception

Return the File on which the resource was written. If the operation fails, then the caller is responsible deciding whether or not the File specified to the constructor needs to be deleted.

Throws:

IOException - if the file exists and is not empty.

IOException - if another process has a lock on the file.

Exception