public class NumberFormat extends Object
This class provides comprehensive and flexible support for a wide variety of localized formats, including
decimal, currency,
percentages, and scientific
Formatting and parsing are based on customizable patterns that can include a combination of
literal characters and special characters that act as placeholders and are replaced by their
localized counterparts. Many characters in a pattern are taken literally; they are matched during
parsing and output unchanged during formatting. Special characters, on the other hand, stand for
other characters, strings, or classes of characters. For example, the '#' character
is replaced by a localized digit.
Often the replacement character is the same as the pattern character. In the U.S. locale, for
example, the ',' grouping character is replaced by the same character ',
'. However, the replacement is still actually happening, and in a different locale, the
grouping character may change to a different character, such as '.'. Some special
characters affect the behavior of the formatter by their presence. For example, if the percent
character is seen, then the value is multiplied by 100 before being displayed.
The characters listed below are used in patterns. Localized symbols use the corresponding
characters taken from corresponding locale symbol collection, which can be found in the
properties files residing in the .
To insert a special character in a pattern as a literal (that is, without any special meaning)
the character must be quoted. There are some exceptions to this which are noted below.
| Symbol | Location | Localized? | Meaning |
|---|---|---|---|
0 |
Number | Yes | Digit |
# |
Number | Yes | Digit, zero shows as absent |
. |
Number | Yes | Decimal separator or monetary decimal separator |
- |
Number | Yes | Minus sign |
, |
Number | Yes | Grouping separator |
E |
Number | Yes | Separates mantissa and exponent in scientific notation; need not be quoted in prefix or suffix |
; |
Subpattern boundary | Yes | Separates positive and negative subpatterns |
% |
Prefix or suffix | Yes | Multiply by 100 and show as percentage |
‰ (\u2030) |
Prefix or suffix | Yes | Multiply by 1000 and show as per mille |
¤ (\u00A4) |
Prefix or suffix | No | Currency sign, replaced by currency symbol; if doubled, replaced by international currency symbol; if present in a pattern, the monetary decimal separator is used instead of the decimal separator |
' |
Prefix or suffix | No | Used to quote special characters in a prefix or suffix; for example,
"'#'#" formats 123 to "#123";
to create a single quote itself, use two in succession, such as
"# o''clock" |
A NumberFormat pattern contains a postive and negative subpattern separated by a
semicolon, such as "#,##0.00;(#,##0.00)". Each subpattern has a prefix, a numeric
part, and a suffix. If there is no explicit negative subpattern, the negative subpattern is the
localized minus sign prefixed to the positive subpattern. That is, "0.00" alone is
equivalent to "0.00;-0.00". If there is an explicit negative subpattern, it serves
only to specify the negative prefix and suffix; the number of digits, minimal digits, and other
characteristics are ignored in the negative subpattern. That means that "#,##0.0#;(#)"
has precisely the same result as "#,##0.0#;(#,##0.0#)".
The prefixes, suffixes, and various symbols used for infinity, digits, thousands separators, decimal separators, etc. may be set to arbitrary values, and they will appear properly during formatting. However, care must be taken that the symbols and strings do not conflict, or parsing will be unreliable. For example, the decimal separator and thousands separator should be distinct characters, or parsing will be impossible.
The grouping separator is a character that separates clusters of integer digits to make large numbers more legible. It commonly used for thousands, but in some locales it separates ten-thousands. The grouping size is the number of digits between the grouping separators, such as 3 for "100,000,000" or 4 for "1 0000 0000".
The pattern itself uses the following grammar:
| pattern | := | subpattern (';'
subpattern)? |
| subpattern | := | prefix? number exponent? suffix? |
| number | := | (integer ('.' fraction)?) |
sigDigits |
| prefix | := | '\u0000'..'\uFFFD' -
specialCharacters |
| suffix | := | '\u0000'..'\uFFFD' -
specialCharacters |
| integer | := | '#'* '0'*'0' |
| fraction | := | '0'* '#'* |
| sigDigits | := | '#'* '@''@'* '#'* |
| exponent | := | 'E' '+'? '0'* '0' |
| padSpec | := | '*' padChar |
| padChar | := | '\u0000'..'\uFFFD' - quote |
Notation:
| X* | 0 or more instances of X |
| X? | 0 or 1 instances of X |
| X|Y | either X or Y |
| C..D | any character from C up to D, inclusive |
| S-T | characters in S, except those in T |
The first subpattern is for positive numbers. The second (optional) subpattern is for negative numbers.
| Modifier and Type | Field and Description |
|---|---|
protected static org.gwtproject.i18n.shared.cldr.NumberConstants |
defaultNumberConstants
Current NumberConstants interface to use, see
setForcedLatinDigits(boolean) for
changing it. |
protected static org.gwtproject.i18n.shared.cldr.NumberConstants |
localizedNumberConstants |
| Modifier | Constructor and Description |
|---|---|
protected |
NumberFormat(org.gwtproject.i18n.shared.cldr.NumberConstants numberConstants,
String pattern,
org.gwtproject.i18n.shared.cldr.CurrencyData cdata,
boolean userSuppliedPattern)
Constructs a format object based on the specified settings.
|
protected |
NumberFormat(String pattern,
org.gwtproject.i18n.shared.cldr.CurrencyData cdata,
boolean userSuppliedPattern)
Constructs a format object for the default locale based on the specified settings.
|
| Modifier and Type | Method and Description |
|---|---|
protected static org.gwtproject.i18n.shared.cldr.NumberConstants |
createLatinNumberConstants(org.gwtproject.i18n.shared.cldr.NumberConstants orig)
Create a delocalized NumberConstants instance from a localized one.
|
static boolean |
forcedLatinDigits()
Returns true if all new NumberFormat instances will use latin digits and related characters
rather than the localized ones.
|
protected void |
format(boolean isNegative,
StringBuilder digits,
int scale)
Format a number with its significant digits already represented in string form.
|
String |
format(double number)
This method formats a double to produce a string.
|
protected String |
format(long value,
int scale)
Format a possibly scaled long value.
|
String |
format(Number number)
This method formats a Number to produce a string.
|
static NumberFormat |
getCurrencyFormat()
Provides the standard currency format for the current locale.
|
static NumberFormat |
getCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
Provides the standard currency format for the current locale using a specified currency.
|
static NumberFormat |
getCurrencyFormat(String currencyCode)
Provides the standard currency format for the current locale using a specified currency.
|
static NumberFormat |
getDecimalFormat()
Provides the standard decimal format for the default locale.
|
static NumberFormat |
getFormat(String pattern)
Gets a
NumberFormat instance for the default locale using the specified pattern
and the default currencyCode. |
static NumberFormat |
getFormat(String pattern,
org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
Gets a custom
NumberFormat instance for the default locale using the specified
pattern and currency code. |
static NumberFormat |
getFormat(String pattern,
String currencyCode)
Gets a custom
NumberFormat instance for the default locale using the specified
pattern and currency code. |
static NumberFormat |
getGlobalCurrencyFormat()
Provides the global currency format for the current locale, using its default currency.
|
static NumberFormat |
getGlobalCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
Provides the global currency format for the current locale, using a specified currency.
|
static NumberFormat |
getGlobalCurrencyFormat(String currencyCode)
Provides the global currency format for the current locale, using a specified currency.
|
protected int |
getGroupingSize()
Returns the number of digits between grouping separators in the integer portion of a number.
|
protected String |
getNegativePrefix()
Returns the prefix to use for negative values.
|
protected String |
getNegativeSuffix()
Returns the suffix to use for negative values.
|
protected org.gwtproject.i18n.shared.cldr.NumberConstants |
getNumberConstants()
Returns the NumberConstants instance for this formatter.
|
String |
getPattern()
Returns the pattern used by this number format.
|
static NumberFormat |
getPercentFormat()
Provides the standard percent format for the default locale.
|
protected String |
getPositivePrefix()
Returns the prefix to use for positive values.
|
protected String |
getPositiveSuffix()
Returns the suffix to use for positive values.
|
static NumberFormat |
getScientificFormat()
Provides the standard scientific format for the default locale.
|
static NumberFormat |
getSimpleCurrencyFormat()
Provides the simple currency format for the current locale using its default currency.
|
static NumberFormat |
getSimpleCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
Provides the simple currency format for the current locale using a specified currency.
|
static NumberFormat |
getSimpleCurrencyFormat(String currencyCode)
Provides the simple currency format for the current locale using a specified currency.
|
protected boolean |
isDecimalSeparatorAlwaysShown()
Returns true if the decimal separator should always be shown.
|
NumberFormat |
overrideFractionDigits(int digits)
Change the number of fractional digits used for formatting with this instance.
|
NumberFormat |
overrideFractionDigits(int minDigits,
int maxDigits)
Change the number of fractional digits used for formatting with this instance.
|
double |
parse(String text)
Parses text to produce a numeric value.
|
double |
parse(String text,
int[] inOutPos)
Parses text to produce a numeric value.
|
protected static String |
remapSeparator(String separator)
Remap a localized separator to an equivalent latin one.
|
static void |
setForcedLatinDigits(boolean useLatinDigits)
Specify whether all new NumberFormat instances will use latin digits and related characters
rather than the localized ones.
|
static int |
toScaledString(StringBuilder buf,
double val)
Appends a scaled string representation to a buffer, returning the scale (which is the number of
places to the right of the end of the string the decimal point should be moved -- i.e., 3.5
would be added to the buffer as "35" and a returned scale of -1).
|
protected static final org.gwtproject.i18n.shared.cldr.NumberConstants localizedNumberConstants
protected static org.gwtproject.i18n.shared.cldr.NumberConstants defaultNumberConstants
setForcedLatinDigits(boolean) for
changing it.protected NumberFormat(org.gwtproject.i18n.shared.cldr.NumberConstants numberConstants,
String pattern,
org.gwtproject.i18n.shared.cldr.CurrencyData cdata,
boolean userSuppliedPattern)
numberConstants - the locale-specific number constants to use for this format -- **NOTE**
subclasses passing their own instance here should pay attention to forcedLatinDigits() and remap localized symbols using createLatinNumberConstants(NumberConstants)pattern - pattern that specify how number should be formattedcdata - currency data that should be useduserSuppliedPattern - true if the pattern was supplied by the userprotected NumberFormat(String pattern, org.gwtproject.i18n.shared.cldr.CurrencyData cdata, boolean userSuppliedPattern)
pattern - pattern that specify how number should be formattedcdata - currency data that should be useduserSuppliedPattern - true if the pattern was supplied by the userpublic static boolean forcedLatinDigits()
public static NumberFormat getCurrencyFormat()
NumberFormat capable of producing and consuming currency format for the
default localepublic static NumberFormat getCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
currencyData - currency data to useNumberFormat capable of producing and consuming currency format for the
current localepublic static NumberFormat getCurrencyFormat(String currencyCode)
currencyCode - valid currency code, as defined in
org.gwtproject.i18n.client.constants.CurrencyCodeMapConstants.propertiesNumberFormat capable of producing and consuming currency format for the
current localeIllegalArgumentException - if the currency code is unknownpublic static NumberFormat getDecimalFormat()
NumberFormat capable of producing and consuming decimal format for the
default localepublic static NumberFormat getFormat(String pattern)
NumberFormat instance for the default locale using the specified pattern
and the default currencyCode.pattern - pattern for this formatterIllegalArgumentException - if the specified pattern is invalidpublic static NumberFormat getFormat(String pattern, org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
NumberFormat instance for the default locale using the specified
pattern and currency code.pattern - pattern for this formattercurrencyData - currency dataIllegalArgumentException - if the specified pattern is invalidpublic static NumberFormat getFormat(String pattern, String currencyCode)
NumberFormat instance for the default locale using the specified
pattern and currency code.pattern - pattern for this formattercurrencyCode - international currency codeIllegalArgumentException - if the specified pattern is invalid or the currency code is
unknownpublic static NumberFormat getGlobalCurrencyFormat()
NumberFormat capable of producing and consuming currency format for the
current localepublic static NumberFormat getGlobalCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
currencyData - currency data to useNumberFormat capable of producing and consuming currency format for the
current localepublic static NumberFormat getGlobalCurrencyFormat(String currencyCode)
currencyCode - valid currency code, as defined in
org.gwtproject.i18n.client.constants.CurrencyCodeMapConstants.propertiesNumberFormat capable of producing and consuming currency format for the
current localeIllegalArgumentException - if the currency code is unknownpublic static NumberFormat getPercentFormat()
NumberFormat capable of producing and consuming percent format for the
default localepublic static NumberFormat getScientificFormat()
NumberFormat capable of producing and consuming scientific format for
the default localepublic static NumberFormat getSimpleCurrencyFormat()
NumberFormat capable of producing and consuming currency format for the
current localepublic static NumberFormat getSimpleCurrencyFormat(org.gwtproject.i18n.shared.cldr.CurrencyData currencyData)
currencyData - currency data to useNumberFormat capable of producing and consuming currency format for the
current localepublic static NumberFormat getSimpleCurrencyFormat(String currencyCode)
currencyCode - valid currency code, as defined in org.gwtproject.i18n.client
.constants.CurrencyCodeMapConstants.propertiesNumberFormat capable of producing and consuming currency format for the
current localeIllegalArgumentException - if the currency code is unknownpublic static void setForcedLatinDigits(boolean useLatinDigits)
useLatinDigits - true if latin digits/etc should be used, false if localized digits/etc
should be used.protected static org.gwtproject.i18n.shared.cldr.NumberConstants createLatinNumberConstants(org.gwtproject.i18n.shared.cldr.NumberConstants orig)
orig - localized NumberConstants instanceprotected static String remapSeparator(String separator)
separator - public static int toScaledString(StringBuilder buf, double val)
buf - val - public String format(double number)
number - The double to formatpublic String format(Number number)
Any Number which is not a BigDecimal, BigInteger, or Long
instance is formatted as a double value.
number - The Number instance to formatpublic String getPattern()
public NumberFormat overrideFractionDigits(int digits)
digits - the exact number of fractional digits for formatted values; must be >= 0this, for chaining purposespublic NumberFormat overrideFractionDigits(int minDigits, int maxDigits)
minDigits that are zero will be omitted from the formatted value.minDigits - the minimum number of fractional digits for formatted values; must be >= 0maxDigits - the maximum number of fractional digits for formatted values; must be >=
minDigitsthis, for chaining purposespublic double parse(String text) throws NumberFormatException
NumberFormatException is thrown if either the
text is empty or if the parse does not consume all characters of the text.text - the string being parsedNumberFormatException - if the entire text could not be converted into a doublepublic double parse(String text, int[] inOutPos) throws NumberFormatException
The method attempts to parse text starting at the index given by pos. If parsing succeeds,
then the index of pos is updated to the index after the last character used
(parsing does not necessarily use all characters up to the end of the string), and the parsed
number is returned. The updated pos can be used to indicate the starting point for
the next call to this method. If an error occurs, then the index of pos is not
changed.
text - the string to be parsedinOutPos - position to pass in and get backNumberFormatException - if the text segment could not be converted into a doubleprotected void format(boolean isNegative,
StringBuilder digits,
int scale)
Example values passed in:
isNegative=true, digits="13", scale=2
isNegative=false, digits="314158", scale=-5
isNegative=false, digits="1" ("0001" would be ok), scale=-4
isNegative - true if the value to be formatted is negativedigits - a StringBuilder containing just the significant digits in the value to be
formatted, the formatted result will be left herescale - the number of places to the right the decimal point should be moved in the digit
string -- negative means the value contains fractional digitsprotected String format(long value, int scale)
value - value to formatscale - the number of places to the right the decimal point should be moved in the digit
string -- negative means the value contains fractional digitsprotected int getGroupingSize()
protected String getNegativePrefix()
protected String getNegativeSuffix()
protected org.gwtproject.i18n.shared.cldr.NumberConstants getNumberConstants()
protected String getPositivePrefix()
protected String getPositiveSuffix()
protected boolean isDecimalSeparatorAlwaysShown()
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