org.apache.commons.lang3
Class CharSetUtils

java.lang.Object
  org.apache.commons.lang3.CharSetUtils

public class CharSetUtils
extends Object

Operations on CharSet instances.

This class handles null input gracefully. An exception will not be thrown for a null input. Each method documents its behaviour in more detail.

#ThreadSafe#

Since:

1.0

Version:

$Id: CharSetUtils.java 1144916 2011-07-10 17:50:21Z ggregory $

See Also:

CharSet

Constructor Summary

CharSetUtils()
CharSetUtils instances should NOT be constructed in standard programming.

Method Summary

static int	count(String str, String... set) Takes an argument in set-syntax, see evaluateSet, and returns the number of characters present in the specified string.
static String	delete(String str, String... set) Takes an argument in set-syntax, see evaluateSet, and deletes any of characters present in the specified string.
static String	keep(String str, String... set) Takes an argument in set-syntax, see evaluateSet, and keeps any of characters present in the specified string.
static String	squeeze(String str, String... set) Squeezes any repetitions of a character that is mentioned in the supplied set.

Methods inherited from class java.lang.Object

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

Constructor Detail

CharSetUtils

public CharSetUtils()

CharSetUtils instances should NOT be constructed in standard programming. Instead, the class should be used as CharSetUtils.evaluateSet(null);.

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Detail

squeeze

public static String squeeze(String str,
                             String... set)

Squeezes any repetitions of a character that is mentioned in the supplied set.

 CharSetUtils.squeeze(null, *)        = null
 CharSetUtils.squeeze("", *)          = ""
 CharSetUtils.squeeze(*, null)        = *
 CharSetUtils.squeeze(*, "")          = *
 CharSetUtils.squeeze("hello", "k-p") = "helo"
 CharSetUtils.squeeze("hello", "a-e") = "hello"
 

Parameters:

str - the string to squeeze, may be null

set - the character set to use for manipulation, may be null

Returns:

the modified String, null if null string input

See Also:

for set-syntax.

count

public static int count(String str,
                        String... set)

Takes an argument in set-syntax, see evaluateSet, and returns the number of characters present in the specified string.

 CharSetUtils.count(null, *)        = 0
 CharSetUtils.count("", *)          = 0
 CharSetUtils.count(*, null)        = 0
 CharSetUtils.count(*, "")          = 0
 CharSetUtils.count("hello", "k-p") = 3
 CharSetUtils.count("hello", "a-e") = 1
 

Parameters:

str - String to count characters in, may be null

set - String[] set of characters to count, may be null

Returns:

the character count, zero if null string input

See Also:

for set-syntax.

keep

public static String keep(String str,
                          String... set)

Takes an argument in set-syntax, see evaluateSet, and keeps any of characters present in the specified string.

 CharSetUtils.keep(null, *)        = null
 CharSetUtils.keep("", *)          = ""
 CharSetUtils.keep(*, null)        = ""
 CharSetUtils.keep(*, "")          = ""
 CharSetUtils.keep("hello", "hl")  = "hll"
 CharSetUtils.keep("hello", "le")  = "ell"
 

Parameters:

str - String to keep characters from, may be null

set - String[] set of characters to keep, may be null

Returns:

the modified String, null if null string input

Since:

2.0

See Also:

for set-syntax.

delete

public static String delete(String str,
                            String... set)

Takes an argument in set-syntax, see evaluateSet, and deletes any of characters present in the specified string.

 CharSetUtils.delete(null, *)        = null
 CharSetUtils.delete("", *)          = ""
 CharSetUtils.delete(*, null)        = *
 CharSetUtils.delete(*, "")          = *
 CharSetUtils.delete("hello", "hl")  = "eo"
 CharSetUtils.delete("hello", "le")  = "ho"
 

Parameters:

str - String to delete characters from, may be null

set - String[] set of characters to delete, may be null

Returns:

the modified String, null if null string input

See Also:

for set-syntax.