Class StringUtils
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Field Summary
Fields -
Method Summary
Modifier and TypeMethodDescriptionstatic void
escapeNumericChar
(Writer out, String str) write the escaped version of a given stringstatic String
escapeNumericChar
(String str) write the escaped version of a given stringstatic boolean
Checks if a String is empty ("") or null.static String[]
Splits the provided text into an array, separator specified.static boolean
startsWithIgnoreWhitespaces
(String prefix, String string) Tests if this string starts with the specified prefix (Ignoring whitespaces)static String
Strips whitespace from the start and end of a String.static String
Strips any of a set of characters from the start and end of a String.static String
Strips any of a set of characters from the end of a String.static String
stripStart
(String str, String stripChars) Strips any of a set of characters from the start of a String.static void
unescapeNumericChar
(Writer out, String str) Unescapes numeric character references found in theString
to aWriter
.static String
Unescapes numeric character referencs found in theString
.
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Field Details
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EMPTY_STRING_ARRAY
An empty immutableString
array.
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Method Details
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startsWithIgnoreWhitespaces
Tests if this string starts with the specified prefix (Ignoring whitespaces)- Parameters:
prefix
-string
-- Returns:
- boolean
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split
Splits the provided text into an array, separator specified. This is an alternative to using StringTokenizer.
The separator is not included in the returned String array. Adjacent separators are treated as one separator.
A
null
input String returnsnull
.StringUtils.split(null, *) = null StringUtils.split("", *) = [] StringUtils.split("a.b.c", '.') = ["a", "b", "c"] StringUtils.split("a..b.c", '.') = ["a", "b", "c"] StringUtils.split("a:b:c", '.') = ["a:b:c"] StringUtils.split("a\tb\nc", null) = ["a", "b", "c"] StringUtils.split("a b c", ' ') = ["a", "b", "c"]
- Parameters:
str
- the String to parse, may be nullseparatorChar
- the character used as the delimiter,null
splits on whitespace- Returns:
- an array of parsed Strings,
null
if null String input
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isEmpty
Checks if a String is empty ("") or null.
StringUtils.isEmpty(null) = true StringUtils.isEmpty("") = true StringUtils.isEmpty(" ") = false StringUtils.isEmpty("bob") = false StringUtils.isEmpty(" bob ") = false
NOTE: This method changed in Lang version 2.0. It no longer trims the String. That functionality is available in isBlank().
- Parameters:
str
- the String to check, may be null- Returns:
true
if the String is empty or null
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strip
Strips whitespace from the start and end of a String.
This removes whitespace. Whitespace is defined by
Character.isWhitespace(char)
.A
null
input String returnsnull
.StringUtils.strip(null) = null StringUtils.strip("") = "" StringUtils.strip(" ") = "" StringUtils.strip("abc") = "abc" StringUtils.strip(" abc") = "abc" StringUtils.strip("abc ") = "abc" StringUtils.strip(" abc ") = "abc" StringUtils.strip(" ab c ") = "ab c"
- Parameters:
str
- the String to remove whitespace from, may be null- Returns:
- the stripped String,
null
if null String input
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strip
Strips any of a set of characters from the start and end of a String. This is similar to
String.trim()
but allows the characters to be stripped to be controlled.A
null
input String returnsnull
. An empty string ("") input returns the empty string.If the stripChars String is
null
, whitespace is stripped as defined byCharacter.isWhitespace(char)
. Alternatively usestrip(String)
.StringUtils.strip(null, *) = null StringUtils.strip("", *) = "" StringUtils.strip("abc", null) = "abc" StringUtils.strip(" abc", null) = "abc" StringUtils.strip("abc ", null) = "abc" StringUtils.strip(" abc ", null) = "abc" StringUtils.strip(" abcyx", "xyz") = " abc"
- Parameters:
str
- the String to remove characters from, may be nullstripChars
- the characters to remove, null treated as whitespace- Returns:
- the stripped String,
null
if null String input
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stripStart
Strips any of a set of characters from the start of a String.
A
null
input String returnsnull
. An empty string ("") input returns the empty string.If the stripChars String is
null
, whitespace is stripped as defined byCharacter.isWhitespace(char)
.StringUtils.stripStart(null, *) = null StringUtils.stripStart("", *) = "" StringUtils.stripStart("abc", "") = "abc" StringUtils.stripStart("abc", null) = "abc" StringUtils.stripStart(" abc", null) = "abc" StringUtils.stripStart("abc ", null) = "abc " StringUtils.stripStart(" abc ", null) = "abc " StringUtils.stripStart("yxabc ", "xyz") = "abc "
- Parameters:
str
- the String to remove characters from, may be nullstripChars
- the characters to remove, null treated as whitespace- Returns:
- the stripped String,
null
if null String input
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stripEnd
Strips any of a set of characters from the end of a String.
A
null
input String returnsnull
. An empty string ("") input returns the empty string.If the stripChars String is
null
, whitespace is stripped as defined byCharacter.isWhitespace(char)
.StringUtils.stripEnd(null, *) = null StringUtils.stripEnd("", *) = "" StringUtils.stripEnd("abc", "") = "abc" StringUtils.stripEnd("abc", null) = "abc" StringUtils.stripEnd(" abc", null) = " abc" StringUtils.stripEnd("abc ", null) = "abc" StringUtils.stripEnd(" abc ", null) = " abc" StringUtils.stripEnd(" abcyx", "xyz") = " abc"
- Parameters:
str
- the String to remove characters from, may be nullstripChars
- the characters to remove, null treated as whitespace- Returns:
- the stripped String,
null
if null String input
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escapeNumericChar
write the escaped version of a given string- Parameters:
str
- string to be encoded- Returns:
- a new escaped
String
,null
if null string input
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escapeNumericChar
write the escaped version of a given string- Parameters:
out
- writer to write this string tostr
- string to be encoded- Throws:
IOException
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unescapeNumericChar
Unescapes numeric character referencs found in the
String
.For example, it will return a unicode string which means the specified numeric character references looks like "ようこそ".
- Parameters:
str
- theString
to unescape, may be null- Returns:
- a new unescaped
String
,null
if null string input
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unescapeNumericChar
Unescapes numeric character references found in the
String
to aWriter
.For example, it will return a unicode string which means the specified numeric character references looks like "ようこそ".
A
null
string input has no effect.- Parameters:
out
- theWriter
used to output unescaped charactersstr
- theString
to unescape, may be null- Throws:
IllegalArgumentException
- if the Writer isnull
IOException
- if error occurs on underlying Writer
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