org.openimaj.data.dataset

Class VFSListDataset<INSTANCE>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<INSTANCE>

org.openimaj.data.dataset.ReadableListDataset<INSTANCE,org.apache.commons.vfs2.FileObject>

org.openimaj.data.dataset.VFSListDataset<INSTANCE>

Type Parameters:

INSTANCE - The type of instance in the dataset

All Implemented Interfaces:

Iterable<INSTANCE>, Collection<INSTANCE>, List<INSTANCE>, Dataset<INSTANCE>, ListDataset<INSTANCE>, Identifiable

public class VFSListDataset<INSTANCE>
extends ReadableListDataset<INSTANCE,org.apache.commons.vfs2.FileObject>
implements Identifiable

A ListDataset backed by a directory of items (either locally or remotely), or items stored in a compressed archive.

As an example, this class can be used to easily create a ListDataset from a directory of images:

 ListDataset<FImage> dataset = new VFSListDataset<FImage>("/path/to/directory/of/images",
                ImageUtilities.FIMAGE_READER);
 

a zip file of images:

 ListDataset<FImage> dataset = new VFSListDataset<FImage>(
                "zip:file:/path/to/images.zip", ImageUtilities.FIMAGE_READER);
 

or even a remote zip of images hosted via http:

 ListDataset<FImage> dataset = new VFSListDataset<FImage>(
                "zip:http://localhost/˜jsh2/thumbnails.zip", ImageUtilities.FIMAGE_READER);
 

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	VFSListDataset.FileObjectISReader<INSTANCE> An adaptor that lets InputStreamObjectReaders be used as a ObjectReader with a FileObject source type.

Field Summary

Fields inherited from class org.openimaj.data.dataset.ReadableListDataset

reader

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
VFSListDataset(String path, InputStreamObjectReader<INSTANCE> reader) Construct a list dataset from any virtual file system source (local directory, remote zip file, etc).
VFSListDataset(String path, ObjectReader<INSTANCE,org.apache.commons.vfs2.FileObject> reader) Construct a list dataset from any virtual file system source (local directory, remote zip file, etc).

Method Summary

Modifier and Type	Method and Description
org.apache.commons.vfs2.FileObject	getFileObject(int index) Get the underlying file descriptor for a particular instance in the dataset.
org.apache.commons.vfs2.FileObject[]	getFileObjects() Get the underlying file descriptors of the files in the dataset
String	getID()
String	getID(int index) Get an identifier for the instance at the given index.
INSTANCE	getInstance(int index) Returns the instance at the specified position in this dataset.
Iterator<INSTANCE>	iterator()
int	numInstances() Returns the number of instances in this dataset.
String	toString()

Methods inherited from class org.openimaj.data.dataset.ReadableListDataset

get, getRandomInstance, indexOfID, size, toIdentifiable

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, equals, hashCode, indexOf, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openimaj.data.identity.Identifiable

equals

Methods inherited from interface java.util.List

add, add, addAll, addAll, clear, contains, containsAll, equals, hashCode, indexOf, isEmpty, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, replaceAll, retainAll, set, sort, spliterator, subList, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

VFSListDataset

public VFSListDataset(String path,
                      InputStreamObjectReader<INSTANCE> reader)
               throws org.apache.commons.vfs2.FileSystemException

Construct a list dataset from any virtual file system source (local directory, remote zip file, etc).

Parameters:

path - the file system path or uri. See the Apache Commons VFS2 documentation for all the details.

reader - the InputStreamObjectReader that reads the data from the VFS

Throws:

org.apache.commons.vfs2.FileSystemException - if an error occurs accessing the VFS

See Also:

"http://commons.apache.org/proper/commons-vfs/filesystems.html"

VFSListDataset

public VFSListDataset(String path,
                      ObjectReader<INSTANCE,org.apache.commons.vfs2.FileObject> reader)
               throws org.apache.commons.vfs2.FileSystemException

Construct a list dataset from any virtual file system source (local directory, remote zip file, etc).

Parameters:

path - the file system path or uri. See the Apache Commons VFS2 documentation for all the details.

reader - the ObjectReader that reads the data from the VFS

Throws:

org.apache.commons.vfs2.FileSystemException - if an error occurs accessing the VFS

See Also:

"http://commons.apache.org/proper/commons-vfs/filesystems.html"

Method Detail

getFileObjects

public org.apache.commons.vfs2.FileObject[] getFileObjects()

Get the underlying file descriptors of the files in the dataset

Returns:

the array of file objects

getFileObject

public org.apache.commons.vfs2.FileObject getFileObject(int index)

Get the underlying file descriptor for a particular instance in the dataset.

Parameters:

index - index of the instance

Returns:

the file object corresponding to the instance

getInstance

public INSTANCE getInstance(int index)

Description copied from interface: ListDataset

Returns the instance at the specified position in this dataset.

Specified by:

getInstance in interface ListDataset<INSTANCE>

Parameters:

index - index of the instance to return

Returns:

the element at the specified position in this list

numInstances

public int numInstances()

Description copied from interface: Dataset

Returns the number of instances in this dataset.

Specified by:

numInstances in interface Dataset<INSTANCE>

Returns:

the number of instances in this list

iterator

public Iterator<INSTANCE> iterator()

Specified by:

iterator in interface Iterable<INSTANCE>

Specified by:

iterator in interface Collection<INSTANCE>

Specified by:

iterator in interface List<INSTANCE>

Overrides:

iterator in class AbstractList<INSTANCE>

getID

public String getID(int index)

Description copied from class: ReadableListDataset

Get an identifier for the instance at the given index. By default this just returns the index converted to a String, but sub-classes should override to to something more sensible if possible.

Overrides:

getID in class ReadableListDataset<INSTANCE,org.apache.commons.vfs2.FileObject>

Parameters:

index - the index

Returns:

the identifier of the instance at the given index

toString

public String toString()

Overrides:

toString in class AbstractCollection<INSTANCE>

getID

public String getID()

Specified by:

getID in interface Identifiable

Returns:

the identifier of this object