edu.stanford.nlp.io
Class FileArrayList

java.lang.Object
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  +--java.util.AbstractCollection
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        +--java.util.AbstractList
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              +--java.util.ArrayList
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                    +--edu.stanford.nlp.io.FileArrayList

All Implemented Interfaces:

Cloneable, Collection, List, RandomAccess, Serializable

public class FileArrayList

extends ArrayList

A FileArrayList maintains a collection of Files. It's really just an ArrayList except that it has some fancier constructors that traverse paths, so as to build up the FileArrayList. It is built from a Collection of paths, or just from a single path. Optionally one can also provide a FileFilter which is applied over the files in a recursive traversal, or else an extension and whether to do recursive traversal, which are used to construct a filter. Note that the Collection argument constructor will behave 'normally' iff none of the Collection elements are directories. If they are directories they will be recursed and files in them added. To get the behavior of putting just directories in the collection one needs to either call addAll(Collection) or else use the constructor FileArrayList(c, failFilt, true), where failFilt is a user-supplied FileFilter that accepts no files. The FileArrayList builds from these constructor arguments a collection of Files, which can be iterated over, etc. Note that a FileArrayList stores the full expanded list of files in memory. This has the advantage that the list can be easily modified, as per a standard collection, but the disadvantage that it may take up a lot of space.

The class provides some additional constructors beyond the two recommended by the Collections package, to allow specifying a FileFilter and similar options. Nevertheless, so as to avoid overburdening the the API, not every possibly useful constructor has been provided where these can be easily synthesized using standard Collections package facilities. Useful idioms to know are:

• To make a FileArrayList from an array of Files or Strings arr:
  FileArrayList fcollect = new FileArrayList(Arrays.asList(arr));
• To make a FileArrayList from a single File or String fi:
  FileArrayList fcollect = new FileArrayList(Collections.singletonList(fi));

This class will throw an IllegalArgumentException if there are things that are not existing Files or String paths to existing files in the input collection (from the Constructor).

See Also:

FileSequentialCollection, Serialized Form

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

FileArrayList()
Creates an empty FileArrayList, with no Files in it.

FileArrayList(Collection c)
Creates a FileArrayList from the passed in Collection.

FileArrayList(Collection c, FileFilter filt)
Creates a FileArrayList from the passed in Collection.

FileArrayList(Collection c, FileFilter filt, boolean includeDirs)
Creates a FileArrayList from the passed in Collection.

FileArrayList(Collection c, String suffix, boolean recursively)
Creates a FileArrayList from the passed in Collection.

FileArrayList(File path, String suffix, boolean recursively)
Creates a FileArrayList from the passed in File path.

Method Summary

static void

main(String[] args) This is simply a debugging aid that tests the functionality of the class.

Methods inherited from class java.util.ArrayList

add, add, addAll, addAll, clear, clone, contains, ensureCapacity, get, indexOf, isEmpty, lastIndexOf, remove, removeRange, set, size, toArray, toArray, trimToSize

Methods inherited from class java.util.AbstractList

equals, hashCode, iterator, listIterator, listIterator, subList

Methods inherited from class java.util.AbstractCollection

containsAll, remove, removeAll, retainAll, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

containsAll, equals, hashCode, iterator, listIterator, listIterator, remove, removeAll, retainAll, subList

Constructor Detail

FileArrayList

public FileArrayList()

Creates an empty FileArrayList, with no Files in it.

FileArrayList

public FileArrayList(Collection c)

Creates a FileArrayList from the passed in Collection. The constructor iterates through the collection. For each element, if it is a File or String, then this file path is traversed for addition to the collection. If the argument is of some other type, an IllegalArgumentException is thrown. For each File or String, if they do not correspond to directories, then they are added to the collection; if they do, they are recursively explored and all non-directories within them are added to the collection.

Parameters:

c - The collection to build the FileArrayList from

FileArrayList

public FileArrayList(File path,
                     String suffix,
                     boolean recursively)

Creates a FileArrayList from the passed in File path. If the File does not correspond to a directory, then it is added to the collection; if it does, it is explored. Files that match the extension, and files in subfolders that match, if appropriate, are added to the collection. This is an additional convenience constructor.

Parameters:

path - file or directory to load from

suffix - suffix (normally "File extension") of files to load

recursively - true means descend into subdirectories as well

FileArrayList

public FileArrayList(Collection c,
                     String suffix,
                     boolean recursively)

Creates a FileArrayList from the passed in Collection. The constructor iterates through the collection. For each element, if it is a File, then the File is added to the collection, if it is a String, then a File corresponding to this String as a file path is added to the collection, and if the argument is of some other type, an IllegalArgumentException is thrown. For the files thus specified, they are included in the collection only if they match an extension filter as specified by the other arguments.

Parameters:

c - Collection of files or directories as Files or Strings

suffix - suffix (normally "File extension") of files to load

recursively - true means descend into subdirectories as well. Note that if a collection member is a directory, this code will always look at the members of this directory. This variable controls whether subdirectories fo the directory are examined.

FileArrayList

public FileArrayList(Collection c,
                     FileFilter filt)

Creates a FileArrayList from the passed in Collection. The constructor iterates through the collection. For each element, if it is a File or String then these file paths are processed as explained below. If the argument is of some other type, an IllegalArgumentException is thrown. For the files specified, if they are not directories, they are included in the collection. If they are directories, files inside them are included iff they match the FileFilter. This will include recursive directory descent iff the FileFilter accepts directories. If the path is a directory then only files within the directory (perhaps recursively) that satisfy the filter are processed. If the pathis a file, then that file is processed regardless of whether it satisfies the filter. (This semantics was adopted, since otherwise there was no easy way to go through all the files in a directory without descending recursively via the specification of a FileFilter.)

Parameters:

c - The collection of file or directory to load from

filt - A FileFilter of files to load. This may be null, in which case all files are accepted.

FileArrayList

public FileArrayList(Collection c,
                     FileFilter filt,
                     boolean includeDirs)

Creates a FileArrayList from the passed in Collection. The constructor iterates through the collection. For each element, if it is a File or String then these file paths are processed as explained below. If the argument is of some other type, an IllegalArgumentException is thrown. For the files specified, if they are not directories, they are included in the collection. If they are directories, files inside them are included iff they match the FileFilter. This will include recursive directory descent iff the FileFilter accepts directories. If the path is a directory then only files within the directory (perhaps recursively) that satisfy the filter are processed. If the pathis a file, then that file is processed regardless of whether it satisfies the filter. (This semantics was adopted, since otherwise there was no easy way to go through all the files in a directory without descending recursively via the specification of a FileFilter.)

Parameters:

c - The collection of file or directory to load from. An argument of null is interpreted like an empty collection.

filt - A FileFilter of files to load. This may be null, in which case all files are accepted.

includeDirs - Whether to include director names in the file list

Method Detail

main

public static void main(String[] args)

This is simply a debugging aid that tests the functionality of the class. The supplied arguments are put in a Collection, and passed to the FileArrayList constructor. An iterator is then used to print the names of all the files in the collection.

Parameters:

args - A list of file paths