Class StringUtils

Method Details

• startsWithIgnoreWhitespaces

  public static boolean startsWithIgnoreWhitespaces(String prefix, String string)

  Tests if this string starts with the specified prefix (Ignoring whitespaces)

  Parameters:

  prefix -

  string -

  Returns:

  boolean

• split

  public static String[] split(String str, char separatorChar)

  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

• isEmpty

  public static boolean isEmpty(String str)

  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

• strip

  public static String strip(String str)

  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

• strip

  public static String strip(String str, String stripChars)

  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(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 null

  stripChars - the characters to remove, null treated as whitespace

  Returns:

  the stripped String, null if null String input

• stripStart

  public static String stripStart(String str, String stripChars)

  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

• stripEnd

  public static String stripEnd(String str, String stripChars)

  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

• escapeNumericChar

  public static String escapeNumericChar(String str)

  write the escaped version of a given string

  Parameters:

  str - string to be encoded

  Returns:

  a new escaped String, null if null string input

• escapeNumericChar

  public static void escapeNumericChar(Writer out, String str) throws IOException

  write the escaped version of a given string

  Parameters:

  out - writer to write this string to

  str - string to be encoded

  Throws:

  IOException

• unescapeNumericChar

  public static String unescapeNumericChar(String str)

  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

• unescapeNumericChar

  public static void unescapeNumericChar(Writer out, String str) throws IOException

  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

  IOException - if error occurs on underlying Writer