au.com.prunge.jgenfile.impl
Class NullGetFileSystemMetadataOperation

java.lang.Object
  |
  +--au.com.prunge.jgenfile.impl.AbstractOperation
        |
        +--au.com.prunge.jgenfile.impl.AbstractFileSystemOperation
              |
              +--au.com.prunge.jgenfile.impl.NullGetFileSystemMetadataOperation

All Implemented Interfaces:

FileSystemOperation, GetFileSystemMetadataOperation, Operation

public class NullGetFileSystemMetadataOperation

extends AbstractFileSystemOperation

implements GetFileSystemMetadataOperation

A get file system metadata operation that does nothing. No metadata is ever returned.

Version:

1.0

Author:

Peter Runge

Constructor Summary

NullGetFileSystemMetadataOperation(au.com.prunge.jgenfile.FileSystem fileSystem, Set metadataKeySet)
Constructs a NullGetFileSystemMetadataOperation.

Method Summary

Map	getMetadata() Always returns an empty map.
Set	getMetadataKeySet() Returns the set of metadata keys this operation is looking up for the file system.
void	runImpl() The actual run() implementation goes in this method.

Methods inherited from class au.com.prunge.jgenfile.impl.AbstractFileSystemOperation

getFileSystem

Methods inherited from class au.com.prunge.jgenfile.impl.AbstractOperation

abort, addOperationHints, checkRun, getLastRunException, getOperationHint, getOperationHints, hasRun, run, setLastRunException, setOperationHint, setOperationHints

Methods inherited from class java.lang.Object

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

Methods inherited from interface au.com.prunge.jgenfile.FileSystemOperation

getFileSystem

Methods inherited from interface au.com.prunge.jgenfile.Operation

abort, addOperationHints, getLastRunException, getOperationHint, getOperationHints, hasRun, run, setOperationHint, setOperationHints

Constructor Detail

NullGetFileSystemMetadataOperation

public NullGetFileSystemMetadataOperation(au.com.prunge.jgenfile.FileSystem fileSystem,
                                          Set metadataKeySet)
                                   throws NullPointerException

Constructs a NullGetFileSystemMetadataOperation.

Parameters:

fileSystem - the file system this operation is for.

metadataKeySet - a set of metadata keys to access.

Throws:

NullPointerException - if metadataKeySet is null.

Method Detail

getMetadataKeySet

public Set getMetadataKeySet()

Description copied from interface: GetFileSystemMetadataOperation

Returns the set of metadata keys this operation is looking up for the file system.

Specified by:

getMetadataKeySet in interface GetFileSystemMetadataOperation

Returns:

a set of MetadataKey objects.

See Also:

GetFileSystemMetadataOperation.getMetadataKeySet()

getMetadata

public Map getMetadata()
                throws OperationNotFinishedException,
                       JGenFileException

Always returns an empty map.

Specified by:

getMetadata in interface GetFileSystemMetadataOperation

Returns:

a map of MetadataKey objects to values.

Throws:

OperationNotFinishedException - if this method was called and the run() method has not finished or has not been called.

JGenFileException - if another error occurs.

See Also:

GetFileSystemMetadataOperation.getMetadata()

runImpl

public void runImpl()
             throws JGenFileException

Description copied from class: AbstractOperation

The actual run() implementation goes in this method. Setting the last run exception and setting hasRun to true is not required by this method as it is handled by the run() method in this class.

If this method completes successfully (i.e. without throwing an exception), the last run exception is set to null indicating no exception occurred and subsequent calls to hasRun() will return true.

If this method throws an exception, the last run exception is filled in and hasRun() subsequent calls to hasRun() will return false.

Specified by:

runImpl in class AbstractOperation

Throws:

JGenFileException - if an error occurs.

See Also:

au.com.prunge.jgenfile.AbstractOperation#runImpl()