org.apache.axis.utils

Class StringUtils


public class StringUtils
extends java.lang.Object

Field Summary

static String[]
EMPTY_STRING_ARRAY
An empty immutable String array.

Method Summary

static String
escapeNumericChar(String str)
write the escaped version of a given string
static void
escapeNumericChar(Writer out, String str)
write the escaped version of a given string
static boolean
isEmpty(String str)
Checks if a String is empty ("") or null.
static String[]
split(String str, char separatorChar)
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
strip(String str)
Strips whitespace from the start and end of a String.
static String
strip(String str, String stripChars)
Strips any of a set of characters from the start and end of a String.
static String
stripEnd(String str, String stripChars)
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 String
unescapeNumericChar(String str)
Unescapes numeric character referencs found in the String.
static void
unescapeNumericChar(Writer out, String str)
Unescapes numeric character references found in the String to a Writer.

Field Details

EMPTY_STRING_ARRAY

public static final String[] EMPTY_STRING_ARRAY
An empty immutable String array.

Method Details

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

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

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

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

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

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

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

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

Copyright B) 2005 Apache Web Services Project. All Rights Reserved.