org.apache.commons.lang
public class CharUtils extends Object
Operations on char primitives and Character objects.
This class tries to handle null
input gracefully.
An exception will not be thrown for a null
input.
Each method documents its behaviour in more detail.
Since: 2.1
Version: $Id: CharUtils.java 437554 2006-08-28 06:21:41Z bayard $
Field Summary | |
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static char | CR
carriage return CR ('\r').
|
static char | LF
linefeed LF ('\n').
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Constructor Summary | |
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CharUtils()
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Method Summary | |
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static boolean | isAscii(char ch) Checks whether the character is ASCII 7 bit. CharUtils.isAscii('a') = true CharUtils.isAscii('A') = true CharUtils.isAscii('3') = true CharUtils.isAscii('-') = true CharUtils.isAscii('\n') = true CharUtils.isAscii('©') = false |
static boolean | isAsciiAlpha(char ch) Checks whether the character is ASCII 7 bit alphabetic. CharUtils.isAsciiAlpha('a') = true CharUtils.isAsciiAlpha('A') = true CharUtils.isAsciiAlpha('3') = false CharUtils.isAsciiAlpha('-') = false CharUtils.isAsciiAlpha('\n') = false CharUtils.isAsciiAlpha('©') = false |
static boolean | isAsciiAlphaLower(char ch) Checks whether the character is ASCII 7 bit alphabetic lower case. CharUtils.isAsciiAlphaLower('a') = true CharUtils.isAsciiAlphaLower('A') = false CharUtils.isAsciiAlphaLower('3') = false CharUtils.isAsciiAlphaLower('-') = false CharUtils.isAsciiAlphaLower('\n') = false CharUtils.isAsciiAlphaLower('©') = false |
static boolean | isAsciiAlphanumeric(char ch) Checks whether the character is ASCII 7 bit numeric. CharUtils.isAsciiAlphanumeric('a') = true CharUtils.isAsciiAlphanumeric('A') = true CharUtils.isAsciiAlphanumeric('3') = true CharUtils.isAsciiAlphanumeric('-') = false CharUtils.isAsciiAlphanumeric('\n') = false CharUtils.isAsciiAlphanumeric('©') = false |
static boolean | isAsciiAlphaUpper(char ch) Checks whether the character is ASCII 7 bit alphabetic upper case. CharUtils.isAsciiAlphaUpper('a') = false CharUtils.isAsciiAlphaUpper('A') = true CharUtils.isAsciiAlphaUpper('3') = false CharUtils.isAsciiAlphaUpper('-') = false CharUtils.isAsciiAlphaUpper('\n') = false CharUtils.isAsciiAlphaUpper('©') = false |
static boolean | isAsciiControl(char ch) Checks whether the character is ASCII 7 bit control. CharUtils.isAsciiControl('a') = false CharUtils.isAsciiControl('A') = false CharUtils.isAsciiControl('3') = false CharUtils.isAsciiControl('-') = false CharUtils.isAsciiControl('\n') = true CharUtils.isAsciiControl('©') = false |
static boolean | isAsciiNumeric(char ch) Checks whether the character is ASCII 7 bit numeric. CharUtils.isAsciiNumeric('a') = false CharUtils.isAsciiNumeric('A') = false CharUtils.isAsciiNumeric('3') = true CharUtils.isAsciiNumeric('-') = false CharUtils.isAsciiNumeric('\n') = false CharUtils.isAsciiNumeric('©') = false |
static boolean | isAsciiPrintable(char ch) Checks whether the character is ASCII 7 bit printable. CharUtils.isAsciiPrintable('a') = true CharUtils.isAsciiPrintable('A') = true CharUtils.isAsciiPrintable('3') = true CharUtils.isAsciiPrintable('-') = true CharUtils.isAsciiPrintable('\n') = false CharUtils.isAsciiPrintable('©') = false |
static char | toChar(Character ch) Converts the Character to a char throwing an exception for CharUtils.toChar(null) = IllegalArgumentException CharUtils.toChar(' ') = ' ' CharUtils.toChar('A') = 'A' |
static char | toChar(Character ch, char defaultValue) Converts the Character to a char handling CharUtils.toChar(null, 'X') = 'X' CharUtils.toChar(' ', 'X') = ' ' CharUtils.toChar('A', 'X') = 'A' |
static char | toChar(String str) Converts the String to a char using the first character, throwing an exception on empty Strings. CharUtils.toChar(null) = IllegalArgumentException CharUtils.toChar("") = IllegalArgumentException CharUtils.toChar("A") = 'A' CharUtils.toChar("BA") = 'B' |
static char | toChar(String str, char defaultValue) Converts the String to a char using the first character, defaulting the value on empty Strings. CharUtils.toChar(null, 'X') = 'X' CharUtils.toChar("", 'X') = 'X' CharUtils.toChar("A", 'X') = 'A' CharUtils.toChar("BA", 'X') = 'B' |
static Character | toCharacterObject(char ch) Converts the character to a Character. For ASCII 7 bit characters, this uses a cache that will return the same Character object each time. CharUtils.toCharacterObject(' ') = ' ' CharUtils.toCharacterObject('A') = 'A' |
static Character | toCharacterObject(String str) Converts the String to a Character using the first character, returning null for empty Strings. For ASCII 7 bit characters, this uses a cache that will return the same Character object each time. CharUtils.toCharacterObject(null) = null CharUtils.toCharacterObject("") = null CharUtils.toCharacterObject("A") = 'A' CharUtils.toCharacterObject("BA") = 'B' |
static int | toIntValue(char ch) Converts the character to the Integer it represents, throwing an exception if the character is not numeric. This method coverts the char '1' to the int 1 and so on. CharUtils.toIntValue('3') = 3 CharUtils.toIntValue('A') = IllegalArgumentException |
static int | toIntValue(char ch, int defaultValue) Converts the character to the Integer it represents, throwing an exception if the character is not numeric. This method coverts the char '1' to the int 1 and so on. CharUtils.toIntValue('3', -1) = 3 CharUtils.toIntValue('A', -1) = -1 |
static int | toIntValue(Character ch) Converts the character to the Integer it represents, throwing an exception if the character is not numeric. This method coverts the char '1' to the int 1 and so on. CharUtils.toIntValue(null) = IllegalArgumentException CharUtils.toIntValue('3') = 3 CharUtils.toIntValue('A') = IllegalArgumentException |
static int | toIntValue(Character ch, int defaultValue) Converts the character to the Integer it represents, throwing an exception if the character is not numeric. This method coverts the char '1' to the int 1 and so on. CharUtils.toIntValue(null, -1) = -1 CharUtils.toIntValue('3', -1) = 3 CharUtils.toIntValue('A', -1) = -1 |
static String | toString(char ch) Converts the character to a String that contains the one character. For ASCII 7 bit characters, this uses a cache that will return the same String object each time. CharUtils.toString(' ') = " " CharUtils.toString('A') = "A" |
static String | toString(Character ch) Converts the character to a String that contains the one character. For ASCII 7 bit characters, this uses a cache that will return the same String object each time. If CharUtils.toString(null) = null CharUtils.toString(' ') = " " CharUtils.toString('A') = "A" |
static String | unicodeEscaped(char ch) Converts the string to the unicode format ' '. This format is the Java source code format. CharUtils.unicodeEscaped(' ') = " " CharUtils.unicodeEscaped('A') = "A" |
static String | unicodeEscaped(Character ch) Converts the string to the unicode format ' '. This format is the Java source code format. If CharUtils.unicodeEscaped(null) = null CharUtils.unicodeEscaped(' ') = " " CharUtils.unicodeEscaped('A') = "A" |
carriage return CR ('\r').
Since: 2.2
See Also: JLF: Escape Sequences
for Character and String Literals
CharUtils
instances should NOT be constructed in standard programming.
Instead, the class should be used as CharUtils.toString('c');
.
This constructor is public to permit tools that require a JavaBean instance to operate.
Checks whether the character is ASCII 7 bit.
CharUtils.isAscii('a') = true CharUtils.isAscii('A') = true CharUtils.isAscii('3') = true CharUtils.isAscii('-') = true CharUtils.isAscii('\n') = true CharUtils.isAscii('©') = false
Parameters: ch the character to check
Returns: true if less than 128
Checks whether the character is ASCII 7 bit alphabetic.
CharUtils.isAsciiAlpha('a') = true CharUtils.isAsciiAlpha('A') = true CharUtils.isAsciiAlpha('3') = false CharUtils.isAsciiAlpha('-') = false CharUtils.isAsciiAlpha('\n') = false CharUtils.isAsciiAlpha('©') = false
Parameters: ch the character to check
Returns: true if between 65 and 90 or 97 and 122 inclusive
Checks whether the character is ASCII 7 bit alphabetic lower case.
CharUtils.isAsciiAlphaLower('a') = true CharUtils.isAsciiAlphaLower('A') = false CharUtils.isAsciiAlphaLower('3') = false CharUtils.isAsciiAlphaLower('-') = false CharUtils.isAsciiAlphaLower('\n') = false CharUtils.isAsciiAlphaLower('©') = false
Parameters: ch the character to check
Returns: true if between 97 and 122 inclusive
Checks whether the character is ASCII 7 bit numeric.
CharUtils.isAsciiAlphanumeric('a') = true CharUtils.isAsciiAlphanumeric('A') = true CharUtils.isAsciiAlphanumeric('3') = true CharUtils.isAsciiAlphanumeric('-') = false CharUtils.isAsciiAlphanumeric('\n') = false CharUtils.isAsciiAlphanumeric('©') = false
Parameters: ch the character to check
Returns: true if between 48 and 57 or 65 and 90 or 97 and 122 inclusive
Checks whether the character is ASCII 7 bit alphabetic upper case.
CharUtils.isAsciiAlphaUpper('a') = false CharUtils.isAsciiAlphaUpper('A') = true CharUtils.isAsciiAlphaUpper('3') = false CharUtils.isAsciiAlphaUpper('-') = false CharUtils.isAsciiAlphaUpper('\n') = false CharUtils.isAsciiAlphaUpper('©') = false
Parameters: ch the character to check
Returns: true if between 65 and 90 inclusive
Checks whether the character is ASCII 7 bit control.
CharUtils.isAsciiControl('a') = false CharUtils.isAsciiControl('A') = false CharUtils.isAsciiControl('3') = false CharUtils.isAsciiControl('-') = false CharUtils.isAsciiControl('\n') = true CharUtils.isAsciiControl('©') = false
Parameters: ch the character to check
Returns: true if less than 32 or equals 127
Checks whether the character is ASCII 7 bit numeric.
CharUtils.isAsciiNumeric('a') = false CharUtils.isAsciiNumeric('A') = false CharUtils.isAsciiNumeric('3') = true CharUtils.isAsciiNumeric('-') = false CharUtils.isAsciiNumeric('\n') = false CharUtils.isAsciiNumeric('©') = false
Parameters: ch the character to check
Returns: true if between 48 and 57 inclusive
Checks whether the character is ASCII 7 bit printable.
CharUtils.isAsciiPrintable('a') = true CharUtils.isAsciiPrintable('A') = true CharUtils.isAsciiPrintable('3') = true CharUtils.isAsciiPrintable('-') = true CharUtils.isAsciiPrintable('\n') = false CharUtils.isAsciiPrintable('©') = false
Parameters: ch the character to check
Returns: true if between 32 and 126 inclusive
Converts the Character to a char throwing an exception for null
.
CharUtils.toChar(null) = IllegalArgumentException CharUtils.toChar(' ') = ' ' CharUtils.toChar('A') = 'A'
Parameters: ch the character to convert
Returns: the char value of the Character
Throws: IllegalArgumentException if the Character is null
Converts the Character to a char handling null
.
CharUtils.toChar(null, 'X') = 'X' CharUtils.toChar(' ', 'X') = ' ' CharUtils.toChar('A', 'X') = 'A'
Parameters: ch the character to convert defaultValue the value to use if the Character is null
Returns: the char value of the Character or the default if null
Converts the String to a char using the first character, throwing an exception on empty Strings.
CharUtils.toChar(null) = IllegalArgumentException CharUtils.toChar("") = IllegalArgumentException CharUtils.toChar("A") = 'A' CharUtils.toChar("BA") = 'B'
Parameters: str the character to convert
Returns: the char value of the first letter of the String
Throws: IllegalArgumentException if the String is empty
Converts the String to a char using the first character, defaulting the value on empty Strings.
CharUtils.toChar(null, 'X') = 'X' CharUtils.toChar("", 'X') = 'X' CharUtils.toChar("A", 'X') = 'A' CharUtils.toChar("BA", 'X') = 'B'
Parameters: str the character to convert defaultValue the value to use if the Character is null
Returns: the char value of the first letter of the String or the default if null
Converts the character to a Character.
For ASCII 7 bit characters, this uses a cache that will return the same Character object each time.
CharUtils.toCharacterObject(' ') = ' ' CharUtils.toCharacterObject('A') = 'A'
Parameters: ch the character to convert
Returns: a Character of the specified character
Converts the String to a Character using the first character, returning null for empty Strings.
For ASCII 7 bit characters, this uses a cache that will return the same Character object each time.
CharUtils.toCharacterObject(null) = null CharUtils.toCharacterObject("") = null CharUtils.toCharacterObject("A") = 'A' CharUtils.toCharacterObject("BA") = 'B'
Parameters: str the character to convert
Returns: the Character value of the first letter of the String
Converts the character to the Integer it represents, throwing an exception if the character is not numeric.
This method coverts the char '1' to the int 1 and so on.
CharUtils.toIntValue('3') = 3 CharUtils.toIntValue('A') = IllegalArgumentException
Parameters: ch the character to convert
Returns: the int value of the character
Throws: IllegalArgumentException if the character is not ASCII numeric
Converts the character to the Integer it represents, throwing an exception if the character is not numeric.
This method coverts the char '1' to the int 1 and so on.
CharUtils.toIntValue('3', -1) = 3 CharUtils.toIntValue('A', -1) = -1
Parameters: ch the character to convert defaultValue the default value to use if the character is not numeric
Returns: the int value of the character
Converts the character to the Integer it represents, throwing an exception if the character is not numeric.
This method coverts the char '1' to the int 1 and so on.
CharUtils.toIntValue(null) = IllegalArgumentException CharUtils.toIntValue('3') = 3 CharUtils.toIntValue('A') = IllegalArgumentException
Parameters: ch the character to convert, not null
Returns: the int value of the character
Throws: IllegalArgumentException if the Character is not ASCII numeric or is null
Converts the character to the Integer it represents, throwing an exception if the character is not numeric.
This method coverts the char '1' to the int 1 and so on.
CharUtils.toIntValue(null, -1) = -1 CharUtils.toIntValue('3', -1) = 3 CharUtils.toIntValue('A', -1) = -1
Parameters: ch the character to convert defaultValue the default value to use if the character is not numeric
Returns: the int value of the character
Converts the character to a String that contains the one character.
For ASCII 7 bit characters, this uses a cache that will return the same String object each time.
CharUtils.toString(' ') = " " CharUtils.toString('A') = "A"
Parameters: ch the character to convert
Returns: a String containing the one specified character
Converts the character to a String that contains the one character.
For ASCII 7 bit characters, this uses a cache that will return the same String object each time.
If null
is passed in, null
will be returned.
CharUtils.toString(null) = null CharUtils.toString(' ') = " " CharUtils.toString('A') = "A"
Parameters: ch the character to convert
Returns: a String containing the one specified character
Converts the string to the unicode format ' '.
This format is the Java source code format.
CharUtils.unicodeEscaped(' ') = " " CharUtils.unicodeEscaped('A') = "A"
Parameters: ch the character to convert
Returns: the escaped unicode string
Converts the string to the unicode format ' '.
This format is the Java source code format.
If null
is passed in, null
will be returned.
CharUtils.unicodeEscaped(null) = null CharUtils.unicodeEscaped(' ') = " " CharUtils.unicodeEscaped('A') = "A"
Parameters: ch the character to convert, may be null
Returns: the escaped unicode string, null if null input