manifold.io

Class FileTreeWalk

java.lang.Object

manifold.io.FileTreeWalk

All Implemented Interfaces:

Iterable<File>

public class FileTreeWalk
extends Object
implements Iterable<File>

This class is intended to implement different file traversal methods. It allows to iterate through all files inside a given directory.

Use File.walk, File.walkTopDown or File.walkBottomUp extension methods to instantiate a FileTreeWalk instance.

If the file path given is just a file, walker iterates only it. If the file path given does not exist, walker iterates nothing, i.e., it's equivalent to an empty sequence.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FileTreeWalk.FileWalkDirection An enumeration to describe possible walk directions.

Constructor Summary

Constructors

Constructor and Description
FileTreeWalk(File start)
FileTreeWalk(File start, FileTreeWalk.FileWalkDirection direction)
FileTreeWalk(File start, FileTreeWalk.FileWalkDirection direction, Function<File,Boolean> onEnter, Consumer<File> onLeave, BiConsumer<File,IOException> onFail, int maxDepth)

Method Summary

Modifier and Type	Method and Description
Iterator<File>	iterator() Returns an iterator walking through files.
FileTreeWalk	maxDepth(int depth) Sets the maximum [depth] of a directory tree to traverse.
FileTreeWalk	onEnter(Function<File,Boolean> function) Sets a predicate [function], that is called on any entered directory before its files are visited and before it is visited itself.
FileTreeWalk	onFail(BiConsumer<File,IOException> function) Set a callback [function], that is called on a directory when it's impossible to get its file list.
FileTreeWalk	onLeave(Consumer<File> function) Sets a callback [function], that is called on any left directory after its files are visited and after it is visited itself.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

count, count, distinctBy, distinctList, filterIndexedTo, filterIndexedToList, filterNotTo, filterNotToList, filterTo, filterToList, first, first, firstOrNull, firstOrNull, flatMap, flatMapTo, fold, forEach, forEachIndexed, indexOfFirst, indexOfLast, intersect, joinTo, joinToString, last, last, lastOrNull, lastOrNull, mapIndexed, mapIndexedNotNull, mapIndexedNotNullTo, mapIndexedNotNullToList, mapIndexedTo, mapIndexedToList, mapNotNull, mapNotNullTo, mapNotNullToList, mapTo, mapToList, maxWith, minWith, partition, reversed, single, single, singleOrNull, singleOrNull, spliterator, subList, subList, subtract, toList, toSet, union

Constructor Detail

FileTreeWalk

public FileTreeWalk(File start,
                    FileTreeWalk.FileWalkDirection direction,
                    Function<File,Boolean> onEnter,
                    Consumer<File> onLeave,
                    BiConsumer<File,IOException> onFail,
                    int maxDepth)

FileTreeWalk

public FileTreeWalk(File start,
                    FileTreeWalk.FileWalkDirection direction)

FileTreeWalk

public FileTreeWalk(File start)

Method Detail

iterator

public Iterator<File> iterator()

Returns an iterator walking through files.

Specified by:

iterator in interface Iterable<File>

onEnter

public FileTreeWalk onEnter(Function<File,Boolean> function)

Sets a predicate [function], that is called on any entered directory before its files are visited and before it is visited itself.

If the [function] returns `false` the directory is not entered and neither it nor its files are visited.

onLeave

public FileTreeWalk onLeave(Consumer<File> function)

Sets a callback [function], that is called on any left directory after its files are visited and after it is visited itself.

onFail

public FileTreeWalk onFail(BiConsumer<File,IOException> function)

Set a callback [function], that is called on a directory when it's impossible to get its file list.

[onEnter] and [onLeave] callback functions are called even in this case.

maxDepth

public FileTreeWalk maxDepth(int depth)

Sets the maximum [depth] of a directory tree to traverse. By default there is no limit.

The value must be positive and [Int.MAX_VALUE] is used to specify an unlimited depth.

With a value of 1, walker visits only the origin directory and all its immediate children, with a value of 2 also grandchildren, etc.