Package org.apache.commons.vfs2.operations

Class AbstractFileOperationProvider

java.lang.Object

org.apache.commons.vfs2.operations.AbstractFileOperationProvider

All Implemented Interfaces:

FileOperationProvider

public abstract class AbstractFileOperationProvider
extends Object
implements FileOperationProvider

Abstracts implementations of FileOperationProvider.

Since:

0.1

Field Summary

Fields inherited from interface org.apache.commons.vfs2.operations.FileOperationProvider

EMPTY_ARRAY

Constructor Summary

Constructors

Constructor	Description
AbstractFileOperationProvider()	Constructs a new instance for subclasses.

Method Summary

Modifier and Type	Method	Description
protected final void	addOperation(Class<? extends FileOperation> operationClass)	Add new FileOperation to list of known operations.
final void	collectOperations(Collection<Class<? extends FileOperation>> operationsList, FileObject file)	Gather available operations for the specified FileObject and put them into specified operationsList.
protected abstract void	doCollectOperations(Collection<Class<? extends FileOperation>> availableOperations, Collection<Class<? extends FileOperation>> resultList, FileObject file)	Gather available operations for the specified FileObject and put them into specified operationsList.
final FileOperation	getOperation(FileObject file, Class<? extends FileOperation> operationClass)	Gets implementation for a given FileObject and FileOperation interface.
protected abstract FileOperation	instantiateOperation(FileObject file, Class<? extends FileOperation> operationClass)	Gets operation instance for specified FileOperation subclass.
protected final Class<? extends FileOperation>	lookupOperation(Class<? extends FileOperation> operationClass)	Find class implementing a specific operation interface.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractFileOperationProvider

public AbstractFileOperationProvider()

Constructs a new instance for subclasses.

Method Details

addOperation

protected final void addOperation(Class<? extends FileOperation> operationClass)
                           throws FileSystemException

Add new FileOperation to list of known operations.

Parameters:

operationClass - a class implementing FileOperation.

Throws:

FileSystemException - if instances of the class cannot be assigned to FileOperation.

collectOperations

public final void collectOperations(Collection<Class<? extends FileOperation>> operationsList,
 FileObject file)
                             throws FileSystemException

Gather available operations for the specified FileObject and put them into specified operationsList.

Specified by:

collectOperations in interface FileOperationProvider

Parameters:

operationsList - the list of available operations for the specified FileObject. The operationList contains classes of available operations, e.g. Class objects.

file - the FileObject for which we want to get the list of available operations.

Throws:

FileSystemException - if list of operations cannot be retrieved.

doCollectOperations

protected abstract void doCollectOperations(Collection<Class<? extends FileOperation>> availableOperations,
 Collection<Class<? extends FileOperation>> resultList,
 FileObject file)
                                     throws FileSystemException

Gather available operations for the specified FileObject and put them into specified operationsList.

Parameters:

availableOperations - the list of available operations for the specified FileObject.

resultList - List to be filled with applicable operations.

file - the FileObject for which we want to get the list of available operations.

Throws:

FileSystemException - if list of operations cannot be retrieved.

See Also:

• collectOperations(Collection operationsList, FileObject file)

getOperation

public final FileOperation getOperation(FileObject file,
 Class<? extends FileOperation> operationClass)
                                 throws FileSystemException

Description copied from interface: FileOperationProvider

Gets implementation for a given FileObject and FileOperation interface.

Specified by:

getOperation in interface FileOperationProvider

Parameters:

file - the FileObject for which we need an operation.

operationClass - the Class which instance we are needed.

Returns:

the required operation instance.

Throws:

FileSystemException - if operation cannot be retrieved.

instantiateOperation

protected abstract FileOperation instantiateOperation(FileObject file,
 Class<? extends FileOperation> operationClass)
                                               throws FileSystemException

Gets operation instance for specified FileOperation subclass.

Parameters:

file - the file this operation should act on.

operationClass - the class of a file operation interface to instantiate.

Returns:

a new file operation

Throws:

FileSystemException - if operation cannot be instantiated.

lookupOperation

protected final Class<? extends FileOperation> lookupOperation(Class<? extends FileOperation> operationClass)
                                                        throws FileSystemException

Find class implementing a specific operation interface.

Parameters:

operationClass - the interface which is requested.

Returns:

never returns null

Throws:

FileSystemException - if operationClass is not a known FileOperation interface.