Package com.aspectran.core.util

Class StringUtils

java.lang.Object

com.aspectran.core.util.StringUtils

public class StringUtils
extends java.lang.Object

Static utility methods pertaining to String or CharSequence instances.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	EMPTY	The empty String

Constructor Summary

Constructors

Constructor	Description
StringUtils()

Method Summary

Modifier and Type	Method	Description
static java.lang.String	arrayToDelimitedString(java.lang.Object[] arr, java.lang.String delim)	Convert a String array into a delimited String (e.g.
static boolean	containsWhitespace(java.lang.CharSequence str)	Check whether the given CharSequence contains any whitespace characters.
static boolean	containsWhitespace(java.lang.String str)	Check whether the given String contains any whitespace characters.
static java.lang.String	convertToHumanFriendlyByteSize(long size)	Convert byte size into human friendly format.
static long	convertToMachineFriendlyByteSize(java.lang.String size)	Convert byte size into machine friendly format.
static java.lang.String	emptyToNull(java.lang.String str)	Returns the given string if it is nonempty; null otherwise.
static boolean	endsWith(java.lang.String str, char suffix)	Test if the given String ends with the specified prefix character.
static boolean	endsWithIgnoreCase(java.lang.String str, java.lang.String suffix)	Test if the given String ends with the specified suffix, ignoring upper/lower case.
static boolean	hasLength(java.lang.CharSequence str)	Check that the given CharSequence is neither null nor of length 0.
static boolean	hasLength(java.lang.String str)	Check that the given String is neither null nor of length 0.
static boolean	hasText(java.lang.CharSequence str)	Check whether the given CharSequence contains actual text.
static boolean	hasText(java.lang.String str)	Check whether the given String contains actual text.
static boolean	isEmpty(java.lang.String str)	Returns true if the given string is null or is the empty string.
static java.lang.String	joinCommaDelimitedList(java.lang.String[] arr)	Convert a String array into a comma delimited String (i.e., CSV).
static java.lang.String	joinCommaDelimitedList(java.util.Collection<?> list)	Convert a Collection into a comma delimited String (i.e., CSV).
static java.lang.String	nullToEmpty(java.lang.String str)	Returns the given string if it is non-null; the empty string otherwise.
static java.util.Locale	parseLocaleString(java.lang.String localeString)	Parse the given localeString value into a Locale.
static java.util.TimeZone	parseTimeZoneString(java.lang.String timeZoneString)	Parse the given timeZoneString value into a TimeZone.
static java.lang.String	replace(java.lang.String str, java.lang.String[] search, java.lang.String[] replace)	Replace all occurrences of a substring within a string with another string.
static java.lang.String	replace(java.lang.String str, java.lang.String search, java.lang.String replace)	Replace all occurrences of a substring within a string with another string.
static int	search(java.lang.CharSequence chars, char c)	Returns the number of times the specified character was found in the target string, or 0 if there is no specified character.
static int	search(java.lang.String str, java.lang.String keyw)	Returns the number of times the specified string was found in the target string, or 0 if there is no specified string.
static int	searchIgnoreCase(java.lang.CharSequence chars, char c)	Returns the number of times the specified character was found in the target string, or 0 if there is no specified character.
static int	searchIgnoreCase(java.lang.String str, java.lang.String keyw)	Returns the number of times the specified string was found in the target string, or 0 if there is no specified string.
static java.lang.String[]	split(java.lang.String str, char delim)	Returns an array of strings separated by the delimiter string.
static java.lang.String[]	split(java.lang.String str, char delim, int size)	Returns an array of strings separated by the delimiter string.
static java.lang.String[]	split(java.lang.String str, java.lang.String delim)	Returns an array of strings separated by the delimiter string.
static java.lang.String[]	split(java.lang.String str, java.lang.String delim, int size)	Returns an array of strings separated by the delimiter string.
static java.lang.String[]	splitCommaDelimitedString(java.lang.String str)	Convert a comma delimited list (e.g., a row from a CSV file) into an array of strings.
static boolean	startsWith(java.lang.String str, char prefix)	Test if the given String starts with the specified prefix character.
static boolean	startsWithIgnoreCase(java.lang.String str, java.lang.String prefix)	Test if the given String starts with the specified prefix, ignoring upper/lower case.
static java.lang.String[]	tokenize(java.lang.String str, java.lang.String delimiters)	Tokenize the given String into a String array via a StringTokenizer.
static java.lang.String[]	tokenize(java.lang.String str, java.lang.String delimiters, boolean trim)	Tokenize the given String into a String array via a StringTokenizer.
static java.lang.String	toLanguageTag(java.util.Locale locale)	Determine the RFC 3066 compliant language tag, as used for the HTTP "Accept-Language" header.
static java.lang.String	trimAllWhitespace(java.lang.String str)	Trim all whitespace from the given String: leading, trailing, and in between characters.
static java.lang.String	trimLeadingCharacter(java.lang.String str, char leadingCharacter)	Trim all occurrences of the supplied leading character from the given String.
static java.lang.String	trimLeadingWhitespace(java.lang.String str)	Trim leading whitespace from the given String.
static java.lang.String	trimTrailingCharacter(java.lang.String str, char trailingCharacter)	Trim all occurrences of the supplied trailing character from the given String.
static java.lang.String	trimTrailingWhitespace(java.lang.String str)	Trim trailing whitespace from the given String.
static java.lang.String	trimWhitespace(java.lang.String str)	Trim leading and trailing whitespace from the given String.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final java.lang.String EMPTY

The empty String

See Also:

Constant Field Values

Constructor Detail

StringUtils

public StringUtils()

Method Detail

hasLength

public static boolean hasLength(java.lang.CharSequence str)

Check that the given CharSequence is neither null nor of length 0.

Note: this method returns true for a CharSequence that purely consists of whitespace.

 StringUtils.hasLength(null) = false
 StringUtils.hasLength("") = false
 StringUtils.hasLength(" ") = true
 StringUtils.hasLength("Hello") = true
 

Parameters:

str - the CharSequence to check (may be null)

Returns:

true if the CharSequence is not null and has length

See Also:

hasText(String)

hasLength

public static boolean hasLength(java.lang.String str)

Check that the given String is neither null nor of length 0.

Note: this method returns true for a String that purely consists of whitespace.

Parameters:

str - the String to check (may be null)

Returns:

true if the String is not null and has length

See Also:

hasLength(CharSequence), hasText(String)

hasText

public static boolean hasText(java.lang.CharSequence str)

Check whether the given CharSequence contains actual text.

More specifically, this method returns true if the CharSequence is not null, its length is greater than 0, and it contains at least one non-whitespace character.

 StringUtils.hasText(null) = false
 StringUtils.hasText("") = false
 StringUtils.hasText(" ") = false
 StringUtils.hasText("12345") = true
 StringUtils.hasText(" 12345 ") = true
 

Parameters:

str - the CharSequence to check (may be null)

Returns:

true if the CharSequence is not null, its length is greater than 0, and it does not contain whitespace only

See Also:

Character.isWhitespace(char)

hasText

public static boolean hasText(java.lang.String str)

Check whether the given String contains actual text.

More specifically, this method returns true if the String is not null, its length is greater than 0, and it contains at least one non-whitespace character.

Parameters:

str - the String to check (may be null)

Returns:

true if the String is not null, its length is greater than 0, and it does not contain whitespace only

See Also:

hasText(CharSequence)

containsWhitespace

public static boolean containsWhitespace(java.lang.CharSequence str)

Check whether the given CharSequence contains any whitespace characters.

Parameters:

str - the CharSequence to check (may be null)

Returns:

true if the CharSequence is not empty and contains at least 1 whitespace character

See Also:

Character.isWhitespace(char)

containsWhitespace

public static boolean containsWhitespace(java.lang.String str)

Check whether the given String contains any whitespace characters.

Parameters:

str - the String to check (may be null)

Returns:

true if the String is not empty and contains at least 1 whitespace character

See Also:

containsWhitespace(CharSequence)

trimWhitespace

public static java.lang.String trimWhitespace(java.lang.String str)

Trim leading and trailing whitespace from the given String.

Parameters:

str - the String to check

Returns:

the trimmed String

See Also:

Character.isWhitespace(char)

trimAllWhitespace

public static java.lang.String trimAllWhitespace(java.lang.String str)

Trim all whitespace from the given String: leading, trailing, and in between characters.

Parameters:

str - the String to check

Returns:

the trimmed String

See Also:

Character.isWhitespace(char)

trimLeadingWhitespace

public static java.lang.String trimLeadingWhitespace(java.lang.String str)

Trim leading whitespace from the given String.

Parameters:

str - the String to check

Returns:

the trimmed String

See Also:

Character.isWhitespace(char)

trimTrailingWhitespace

public static java.lang.String trimTrailingWhitespace(java.lang.String str)

Trim trailing whitespace from the given String.

Parameters:

str - the String to check

Returns:

the trimmed String

See Also:

Character.isWhitespace(char)

trimLeadingCharacter

public static java.lang.String trimLeadingCharacter(java.lang.String str,
                                                    char leadingCharacter)

Trim all occurrences of the supplied leading character from the given String.

Parameters:

str - the String to check

leadingCharacter - the leading character to be trimmed

Returns:

the trimmed String

trimTrailingCharacter

public static java.lang.String trimTrailingCharacter(java.lang.String str,
                                                     char trailingCharacter)

Trim all occurrences of the supplied trailing character from the given String.

Parameters:

str - the String to check

trailingCharacter - the trailing character to be trimmed

Returns:

the trimmed String

startsWithIgnoreCase

public static boolean startsWithIgnoreCase(java.lang.String str,
                                           java.lang.String prefix)

Test if the given String starts with the specified prefix, ignoring upper/lower case.

Parameters:

str - the String to check

prefix - the prefix to look for

Returns:

true if the String starts with the prefix, case insensitive, or both null

See Also:

String.startsWith(java.lang.String, int)

endsWithIgnoreCase

public static boolean endsWithIgnoreCase(java.lang.String str,
                                         java.lang.String suffix)

Test if the given String ends with the specified suffix, ignoring upper/lower case.

Parameters:

str - the String to check

suffix - the suffix to look for

Returns:

true if the String ends with the suffix, case insensitive, or both null

See Also:

String.endsWith(java.lang.String)

isEmpty

public static boolean isEmpty(java.lang.String str)

Returns true if the given string is null or is the empty string.

Parameters:

str - a string reference to check

Returns:

true if the string is null or is the empty string

nullToEmpty

public static java.lang.String nullToEmpty(java.lang.String str)

Returns the given string if it is non-null; the empty string otherwise.

Parameters:

str - the string to test and possibly return

Returns:

string itself if it is non-null; "" if it is null

emptyToNull

public static java.lang.String emptyToNull(java.lang.String str)

Returns the given string if it is nonempty; null otherwise.

Parameters:

str - the string to test and possibly return

Returns:

string itself if it is nonempty; null if it is empty or null

startsWith

public static boolean startsWith(java.lang.String str,
                                 char prefix)

Test if the given String starts with the specified prefix character.

Parameters:

str - the String to check

prefix - the prefix character to look for

Returns:

true if the string starts with the specified prefix; otherwise false

See Also:

String.startsWith(java.lang.String, int)

endsWith

public static boolean endsWith(java.lang.String str,
                               char suffix)

Test if the given String ends with the specified prefix character.

Parameters:

str - the String to check

suffix - the prefix character to look for

Returns:

true if the string ends with the specified suffix; otherwise false

See Also:

String.endsWith(java.lang.String)

replace

public static java.lang.String replace(java.lang.String str,
                                       java.lang.String search,
                                       java.lang.String replace)

Replace all occurrences of a substring within a string with another string.

Parameters:

str - String to examine

search - String to replace

replace - String to insert

Returns:

a String with the replacements

replace

public static java.lang.String replace(java.lang.String str,
                                       java.lang.String[] search,
                                       java.lang.String[] replace)

Replace all occurrences of a substring within a string with another string.

Parameters:

str - String to examine

search - String array to replace

replace - String array to insert

Returns:

a String with the replacements

split

public static java.lang.String[] split(java.lang.String str,
                                       java.lang.String delim)

Returns an array of strings separated by the delimiter string.

Parameters:

str - the string to be separated

delim - the delimiter

Returns:

an array, containing the splitted strings

split

public static java.lang.String[] split(java.lang.String str,
                                       java.lang.String delim,
                                       int size)

Returns an array of strings separated by the delimiter string.

Parameters:

str - the string to be separated

delim - the delimiter

size - the size of the array

Returns:

an array, containing the splitted strings

split

public static java.lang.String[] split(java.lang.String str,
                                       char delim)

Returns an array of strings separated by the delimiter string.

Parameters:

str - the string to be separated

delim - the delimiter

Returns:

an array, containing the splitted strings

split

public static java.lang.String[] split(java.lang.String str,
                                       char delim,
                                       int size)

Returns an array of strings separated by the delimiter string.

Parameters:

str - the string to be separated

delim - the delimiter

size - the size of the array

Returns:

an array, containing the splitted strings

search

public static int search(java.lang.String str,
                         java.lang.String keyw)

Returns the number of times the specified string was found in the target string, or 0 if there is no specified string.

Parameters:

str - the target string

keyw - the string to find

Returns:

the number of times the specified string was found

searchIgnoreCase

public static int searchIgnoreCase(java.lang.String str,
                                   java.lang.String keyw)

Returns the number of times the specified string was found in the target string, or 0 if there is no specified string. When searching for the specified string, it is not case-sensitive.

Parameters:

str - the target string

keyw - the string to find

Returns:

the number of times the specified string was found

search

public static int search(java.lang.CharSequence chars,
                         char c)

Returns the number of times the specified character was found in the target string, or 0 if there is no specified character.

Parameters:

chars - the target string

c - the character to find

Returns:

the number of times the specified character was found

searchIgnoreCase

public static int searchIgnoreCase(java.lang.CharSequence chars,
                                   char c)

Returns the number of times the specified character was found in the target string, or 0 if there is no specified character. When searching for the specified character, it is not case-sensitive.

Parameters:

chars - the target string

c - the character to find

Returns:

the number of times the specified character was found

tokenize

public static java.lang.String[] tokenize(java.lang.String str,
                                          java.lang.String delimiters)

Tokenize the given String into a String array via a StringTokenizer.

Parameters:

str - the String to tokenize

delimiters - the delimiter characters

Returns:

an array of the tokens

tokenize

public static java.lang.String[] tokenize(java.lang.String str,
                                          java.lang.String delimiters,
                                          boolean trim)

Tokenize the given String into a String array via a StringTokenizer.

Parameters:

str - the String to tokenize

delimiters - the delimiter characters

trim - trim the tokens via String's trim

Returns:

an array of the tokens

arrayToDelimitedString

public static java.lang.String arrayToDelimitedString(java.lang.Object[] arr,
                                                      java.lang.String delim)

Convert a String array into a delimited String (e.g. CSV).

Useful for toString() implementations.

Parameters:

arr - the array to display

delim - the delimiter to use (typically a ",")

Returns:

the delimited String

splitCommaDelimitedString

public static java.lang.String[] splitCommaDelimitedString(java.lang.String str)

Convert a comma delimited list (e.g., a row from a CSV file) into an array of strings.

Parameters:

str - the input String

Returns:

an array of strings, or the empty array in case of empty input

joinCommaDelimitedList

public static java.lang.String joinCommaDelimitedList(java.lang.String[] arr)

Convert a String array into a comma delimited String (i.e., CSV).

Parameters:

arr - the array to display

Returns:

the delimited String

joinCommaDelimitedList

public static java.lang.String joinCommaDelimitedList(java.util.Collection<?> list)

Convert a Collection into a comma delimited String (i.e., CSV).

Parameters:

list - the collection

Returns:

the delimited String

parseLocaleString

public static java.util.Locale parseLocaleString(java.lang.String localeString)

Parse the given localeString value into a Locale.

This is the inverse operation of Locale's toString.

Parameters:

localeString - the locale String, following Locale's toString() format ("en", "en_UK", etc); also accepts spaces as separators, as an alternative to underscores

Returns:

a corresponding Locale instance

Throws:

java.lang.IllegalArgumentException - in case of an invalid locale specification

toLanguageTag

public static java.lang.String toLanguageTag(java.util.Locale locale)

Determine the RFC 3066 compliant language tag, as used for the HTTP "Accept-Language" header.

Parameters:

locale - the Locale to transform to a language tag

Returns:

the RFC 3066 compliant language tag as String

parseTimeZoneString

public static java.util.TimeZone parseTimeZoneString(java.lang.String timeZoneString)

Parse the given timeZoneString value into a TimeZone.

Parameters:

timeZoneString - the time zone String, following TimeZone.getTimeZone(String) but throwing IllegalArgumentException in case of an invalid time zone specification

Returns:

a corresponding TimeZone instance

Throws:

java.lang.IllegalArgumentException - in case of an invalid time zone specification

convertToHumanFriendlyByteSize

public static java.lang.String convertToHumanFriendlyByteSize(long size)

Convert byte size into human friendly format.

Parameters:

size - the number of bytes

Returns:

a human friendly byte size (includes units)

convertToMachineFriendlyByteSize

public static long convertToMachineFriendlyByteSize(java.lang.String size)

Convert byte size into machine friendly format.

Parameters:

size - the human friendly byte size (includes units)

Returns:

a number of bytes

Throws:

java.lang.NumberFormatException - if failed parse given size