de.schlichtherle.io.util
Class SuffixSet

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractSet
          de.schlichtherle.util.CanonicalStringSet
              de.schlichtherle.io.util.SuffixSet

All Implemented Interfaces:

Iterable, Collection, Set

public final class SuffixSet
extends CanonicalStringSet

An ordered set of canonicalized suffixes. A SuffixSet can be converted into a string representation by calling CanonicalStringSet.toString().

A suffix is the part of a file name string after the last dot. It must not contain the character '|'. A suffix in canonical form (or canonical suffix for short) is a lowercase string which is not empty and does not start with a dot ('.').

For example, the suffix "zip" is in canonical form, while the suffixes "", "Zip", "ZIP", ".zip", ".Zip", ".ZIP", and "zip|Zip|ZIP|.zip|.Zip|.ZIP" aren't.

A suffix list is a string which consists of zero or more suffixes which are separated by the character '|'. Note that in general, a suffix list is just a sequence of suffixes. In particular, a suffix list may be empty (but not null) and its suffixes don't have to be in canonical form, may be duplicated in the list and may appear in arbitrary order.

Suffix lists have a canonical form, too: A suffix list in canonical form (or canonical suffix list for short) is a suffix list which contains only canonical suffixes in natural sort order and does not contain any duplicates (so it's actually a set).

A suffix list can be canonicalized using this class by calling new {@link #SuffixSet(String) SuffixSet(list)}.{@link #toString()}.

Unless otherwise documented, all Set methods work on the canonical form of the suffixes in this set.

Null suffixes are not permitted in this set.

Since:

TrueZIP 6.5

Version:

$Id: SuffixSet.java 5e709f50671d 2010/11/05 11:52:07 christian $

Author:

Christian Schlichtherle

Field Summary

private static char	PREFIX The optional prefix for suffixes.
private static char	SEPARATOR The separator for suffixes in lists.

Constructor Summary

SuffixSet()
Constructs a new, empty suffix set.

SuffixSet(Collection c)
Constructs a new suffix set by adding the canonical form of all suffixes for all suffix lists in the given collection.

SuffixSet(String list)
Constructs a new suffix set from the given suffix list.

Method Summary

protected String	canonicalize(String suffix) Returns the canonical form of suffix or null if the given suffix does not have a canonical form.
String	toRegex() Returns a case insensitive regular expression to match (file) paths against the suffixes in this set.

Methods inherited from class de.schlichtherle.util.CanonicalStringSet

add, addAll, addAll, canonical, clear, contains, containsAll, containsAll, isEmpty, iterator, originalIterator, remove, removeAll, removeAll, retainAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

addAll, containsAll, retainAll

Field Detail

SEPARATOR

private static final char SEPARATOR

The separator for suffixes in lists.

See Also:

Constant Field Values

PREFIX

private static final char PREFIX

The optional prefix for suffixes.

See Also:

Constant Field Values

Constructor Detail

SuffixSet

public SuffixSet()

Constructs a new, empty suffix set.

SuffixSet

public SuffixSet(String list)

Constructs a new suffix set from the given suffix list.

Parameters:

list - A suffix list - may be null to construct an empty set.

SuffixSet

public SuffixSet(Collection c)

Constructs a new suffix set by adding the canonical form of all suffixes for all suffix lists in the given collection.

Parameters:

c - A collection of suffix lists - may be null to construct an empty set.

Throws:

ClassCastException - If the collection does not only contain Strings.

Method Detail

canonicalize

protected String canonicalize(String suffix)

Returns the canonical form of suffix or null if the given suffix does not have a canonical form. An example of the latter case is the empty string.

Overrides:

canonicalize in class CanonicalStringSet

Parameters:

suffix - The string to get canonicalized. Never null and never contains the separator.

Returns:

The canonical form of s or null if s does not have a canonical form.

toRegex

public String toRegex()

Returns a case insensitive regular expression to match (file) paths against the suffixes in this set. If the regular expression matches, the matching suffix is captured as the first matching group. If this suffix set is empty, an unmatchable expression is returned.