CharSet¶

public class org.apache.commons.lang3.CharSet implements Serializable [source]¶

A set of characters.

Instances are immutable, but instances of subclasses may not be.

#ThreadSafe#

Since:: 1.0

Constructors¶

CharSet(String[])

Constructs a new CharSet using the set syntax.

protected CharSet(String... set)[source]¶

Constructs a new CharSet using the set syntax. Each string is merged in with the set.

Parameters:: set – Strings to merge into the initial set.
Throws:: java.lang.NullPointerException – Thrown if set is null.

Fields and constants¶

`ASCII_ALPHA`	A CharSet defining ASCII alphabetic characters “a-zA-Z”.
`ASCII_ALPHA_LOWER`	A CharSet defining ASCII alphabetic characters “a-z”.
`ASCII_ALPHA_UPPER`	A CharSet defining ASCII alphabetic characters “A-Z”.
`ASCII_NUMERIC`	A CharSet defining ASCII alphabetic characters “0-9”.
`COMMON`	A Map of the common cases used in the factory.
`EMPTY`	A CharSet defining no characters.

public static final CharSet ASCII_ALPHA[source]¶

A CharSet defining ASCII alphabetic characters “a-zA-Z”.

Since:: 2.0

public static final CharSet ASCII_ALPHA_LOWER[source]¶

A CharSet defining ASCII alphabetic characters “a-z”.

Since:: 2.0

public static final CharSet ASCII_ALPHA_UPPER[source]¶

A CharSet defining ASCII alphabetic characters “A-Z”.

Since:: 2.0

public static final CharSet ASCII_NUMERIC[source]¶

A CharSet defining ASCII alphabetic characters “0-9”.

Since:: 2.0

protected static final Map<String, CharSet> COMMON[source]¶

A Map of the common cases used in the factory.

Subclasses can add more common patterns if desired.

Since:: 2.0

public static final CharSet EMPTY[source]¶

A CharSet defining no characters.

Since:: 2.0

Methods¶

`add(String)`	Add a set definition string to the `CharSet`.
`contains(char)`	Tests whether this `CharSet` contain the specified character `ch`.
`equals(Object)`	Compares two `CharSet` objects, returning true if they represent exactly the same set of characters defined in the same way.
`getInstance(String[])`	Gets a new CharSet using the syntax described below.
`hashCode()`	Gets a hash code compatible with the equals method.
`toString()`	Gets a string representation of the set.

protected void add(String str)[source]¶

Add a set definition string to the CharSet.

Parameters:: str – set definition string

public boolean contains(char ch)[source]¶

Tests whether this CharSet contain the specified character ch.

Examples using the negation character:

    CharSet.getInstance("^a-c").contains('a') = false
    CharSet.getInstance("^a-c").contains('d') = true
    CharSet.getInstance("^^a-c").contains('a') = true // (only '^' is negated)
    CharSet.getInstance("^^a-c").contains('^') = false
    CharSet.getInstance("^a-cd-f").contains('d') = true
    CharSet.getInstance("a-c^").contains('^') = true
    CharSet.getInstance("^", "a-c").contains('^') = true

Parameters:: ch – The character to check.
Returns:: true if the set contains the characters.

@Override public boolean equals(Object obj)[source]¶

Compares two CharSet objects, returning true if they represent exactly the same set of characters defined in the same way.

The two sets abc and a-c are not equal according to this method.

Parameters:: obj – The object to compare.
Returns:: true if equal.
Since:: 2.0

public static CharSet getInstance(String... setStrs)[source]¶

Gets a new CharSet using the syntax described below.

null or empty string (“”) - set containing no characters
Single character, such as “a” - set containing just that character
Multi character, such as “a-e” - set containing characters from one character to the other
Negated, such as “^a” or “^a-e” - set containing all characters except those defined
Combinations, such as “abe-g” - set containing all the characters from the individual sets

The matching order is:

Negated multi character range, such as “^a-e”
Ordinary multi character range, such as “a-e”
Negated single character, such as “^a”
Ordinary single character, such as “a”

Matching works left to right. Once a match is found the search starts again from the next character.

If the same range is defined twice using the same syntax, only one range will be kept. Thus, “a-ca-c” creates only one range of “a-c”.

If the start and end of a range are in the wrong order, they are reversed. Thus “a-e” is the same as “e-a”. As a result, “a-ee-a” would create only one range, as the “a-e” and “e-a” are the same.

The set of characters represented is the union of the specified ranges.

There are two ways to add a literal negation character (^):

As the last character in a string, e.g. CharSet.getInstance("a-z^")
As a separate element, e.g. CharSet.getInstance("^", "a-z")

Examples using the negation character:

    CharSet.getInstance("^a-c").contains('a') = false
    CharSet.getInstance("^a-c").contains('d') = true
    CharSet.getInstance("^^a-c").contains('a') = true // (only '^' is negated)
    CharSet.getInstance("^^a-c").contains('^') = false
    CharSet.getInstance("^a-cd-f").contains('d') = true
    CharSet.getInstance("a-c^").contains('^') = true
    CharSet.getInstance("^", "a-c").contains('^') = true

All CharSet objects returned by this method will be immutable.

Parameters:: setStrs – Strings to merge into the set, may be null.
Returns:: A CharSet instance.
Since:: 2.4

@Override public int hashCode()[source]¶

Gets a hash code compatible with the equals method.

Returns:: A suitable hash code.
Since:: 2.0

@Override public String toString()[source]¶

Gets a string representation of the set.

Returns:: string representation of the set.