Class StringUtils

Parameters: str string to be encoded

Returns: a new escaped String, null if null string input

Parameters: out writer to write this string to str string to be encoded

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

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 returns null.

 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 null separatorChar the character used as the delimiter, null splits on whitespace

Returns: an array of parsed Strings, null if null String input

Parameters: prefix string

Returns: boolean

Strips whitespace from the start and end of a String.

This removes whitespace. Whitespace is defined by Character#isWhitespace(char).

A null input String returns null.

 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

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 returns null. An empty string ("") input returns the empty string.

If the stripChars String is null, whitespace is stripped as defined by Character#isWhitespace(char). Alternatively use strip.

 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 null stripChars the characters to remove, null treated as whitespace

Returns: the stripped String, null if null String input

Strips any of a set of characters from the end of a String.

A null input String returns null. An empty string ("") input returns the empty string.

If the stripChars String is null, whitespace is stripped as defined by Character#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 null stripChars the characters to remove, null treated as whitespace

Returns: the stripped String, null if null String input

Strips any of a set of characters from the start of a String.

A null input String returns null. An empty string ("") input returns the empty string.

If the stripChars String is null, whitespace is stripped as defined by Character#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 null stripChars the characters to remove, null treated as whitespace

Returns: the stripped String, null if null String input

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 the String to unescape, may be null

Returns: a new unescaped String, null if null string input

Unescapes numeric character references found in the String to a Writer.

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 the Writer used to output unescaped characters str the String to unescape, may be null

Throws: IllegalArgumentException if the Writer is null java.io.IOException if error occurs on underlying Writer