DecimalFormat
public
class
DecimalFormat
extends NumberFormat
java.lang.Object | |||
↳ | java.text.Format | ||
↳ | java.text.NumberFormat | ||
↳ | java.text.DecimalFormat |
DecimalFormat
is a concrete subclass of
NumberFormat
that formats decimal numbers. It has a variety of
features designed to make it possible to parse and format numbers in any
locale, including support for Western, Arabic, and Indic digits. It also
supports different kinds of numbers, including integers (123), fixed-point
numbers (123.4), scientific notation (1.23E4), percentages (12%), and
currency amounts ($123). All of these can be localized.
To obtain a NumberFormat
for a specific locale, including the
default locale, call one of NumberFormat
's factory methods, such
as getInstance()
. In general, do not call the
DecimalFormat
constructors directly, since the
NumberFormat
factory methods may return subclasses other than
DecimalFormat
. If you need to customize the format object, do
something like this:
NumberFormat f = NumberFormat.getInstance(loc); if (f instanceof DecimalFormat) { ((DecimalFormat) f).setDecimalSeparatorAlwaysShown(true); }
A DecimalFormat
comprises a pattern and a set of
symbols. The pattern may be set directly using
applyPattern()
, or indirectly using the API methods. The
symbols are stored in a DecimalFormatSymbols
object. When using
the NumberFormat
factory methods, the pattern and symbols are
read from localized ResourceBundle
s.
Patterns
DecimalFormat
patterns have the following syntax:
Pattern: PositivePattern PositivePattern ; NegativePattern PositivePattern: Prefixopt Number Suffixopt NegativePattern: Prefixopt Number Suffixopt Prefix: any Unicode characters except \uFFFE, \uFFFF, and special characters Suffix: any Unicode characters except \uFFFE, \uFFFF, and special characters Number: Integer Exponentopt Integer . Fraction Exponentopt Integer: MinimumInteger # # Integer # , Integer MinimumInteger: 0 0 MinimumInteger 0 , MinimumInteger Fraction: MinimumFractionopt OptionalFractionopt MinimumFraction: 0 MinimumFractionopt OptionalFraction: # OptionalFractionopt Exponent: E MinimumExponent MinimumExponent: 0 MinimumExponentopt
A DecimalFormat
pattern contains a positive and negative
subpattern, for example, "#,##0.00;(#,##0.00)"
. Each
subpattern has a prefix, numeric part, and suffix. The negative subpattern
is optional; if absent, then the positive subpattern prefixed with the
minus sign ('-' U+002D HYPHEN-MINUS
) is used as the
negative 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 all the same as the positive
pattern. That means that "#,##0.0#;(#)"
produces precisely
the same behavior as "#,##0.0#;(#,##0.0#)"
.
The prefixes, suffixes, and various symbols used for infinity, digits,
grouping 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, either the positive and negative prefixes or the
suffixes must be distinct for DecimalFormat.parse()
to be able
to distinguish positive from negative values. (If they are identical, then
DecimalFormat
will behave as if no negative subpattern was
specified.) Another example is that the decimal separator and grouping
separator should be distinct characters, or parsing will be impossible.
The grouping separator is commonly used for thousands, but in some
countries it separates ten-thousands. The grouping size is a constant number
of digits between the grouping characters, such as 3 for 100,000,000 or 4 for
1,0000,0000. If you supply a pattern with multiple grouping characters, the
interval between the last one and the end of the integer is the one that is
used. So "#,##,###,####"
== "######,####"
==
"##,####,####"
.
Special Pattern Characters
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. They must be quoted, unless noted otherwise, if they are to appear in the prefix or suffix as literals.
The characters listed here are used in non-localized patterns. Localized
patterns use the corresponding characters taken from this formatter's
DecimalFormatSymbols
object instead, and these characters lose
their special status. Two exceptions are the currency sign and quote, which
are not localized.
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 or monetary 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 value ¤
(\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/grouping separators are used instead of the decimal/grouping separators. '
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 a row:"# o''clock"
.
Scientific Notation
Numbers in scientific notation are expressed as the product of a mantissa
and a power of ten, for example, 1234 can be expressed as 1.234 x 10^3. The
mantissa is often in the range 1.0 ≤ x < 10.0, but it need not
be.
DecimalFormat
can be instructed to format and parse scientific
notation only via a pattern; there is currently no factory method
that creates a scientific notation format. In a pattern, the exponent
character immediately followed by one or more digit characters indicates
scientific notation. Example: "0.###E0"
formats the number
1234 as "1.234E3"
.
- The number of digit characters after the exponent character gives the
minimum exponent digit count. There is no maximum. Negative exponents are
formatted using the localized minus sign, not the prefix and suffix
from the pattern. This allows patterns such as
"0.###E0 m/s"
. - The minimum and maximum number of integer digits are interpreted
together:
- If the maximum number of integer digits is greater than their minimum number
and greater than 1, it forces the exponent to be a multiple of the maximum
number of integer digits, and the minimum number of integer digits to be
interpreted as 1. The most common use of this is to generate
engineering notation, in which the exponent is a multiple of three,
e.g.,
"##0.#####E0"
. Using this pattern, the number 12345 formats to"12.345E3"
, and 123456 formats to"123.456E3"
. - Otherwise, the minimum number of integer digits is achieved by adjusting the
exponent. Example: 0.00123 formatted with
"00.###E0"
yields"12.3E-4"
.
- If the maximum number of integer digits is greater than their minimum number
and greater than 1, it forces the exponent to be a multiple of the maximum
number of integer digits, and the minimum number of integer digits to be
interpreted as 1. The most common use of this is to generate
engineering notation, in which the exponent is a multiple of three,
e.g.,
- The number of significant digits in the mantissa is the sum of the
minimum integer and maximum fraction digits, and is
unaffected by the maximum integer digits. For example, 12345 formatted with
"##0.##E0"
is"12.3E3"
. To show all digits, set the significant digits count to zero. The number of significant digits does not affect parsing. - Exponential patterns may not contain grouping separators.
Rounding
DecimalFormat
provides rounding modes defined in
RoundingMode
for formatting. By default, it uses
RoundingMode.HALF_EVEN
.
Digits
For formatting,DecimalFormat
uses the ten consecutive
characters starting with the localized zero digit defined in the
DecimalFormatSymbols
object as digits. For parsing, these
digits as well as all Unicode decimal digits, as defined by
Character.digit
, are recognized.
Special Values
NaN
is formatted as a string, which typically has a single character
\uFFFD
. This string is determined by the
DecimalFormatSymbols
object. This is the only value for which
the prefixes and suffixes are not used.
Infinity is formatted as a string, which typically has a single character
\u221E
, with the positive or negative prefixes and suffixes
applied. The infinity string is determined by the
DecimalFormatSymbols
object.
Negative zero ("-0"
) parses to
BigDecimal(0)
ifisParseBigDecimal()
is true,Long(0)
ifisParseBigDecimal()
is false andisParseIntegerOnly()
is true,Double(-0.0)
if bothisParseBigDecimal()
andisParseIntegerOnly()
are false.
Synchronization
Decimal formats are generally not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.
Example
// Print out a number using the localized number, integer, currency, // and percent format for each locale
Locale[] locales = NumberFormat.getAvailableLocales(); double myNumber = -1234.56; NumberFormat form; for (int j = 0; j < 4; ++j) { System.out.println("FORMAT"); for (int i = 0; i < locales.length; ++i) { if (locales[i].getCountry().length() == 0) { continue; // Skip language-only locales } System.out.print(locales[i].getDisplayName()); switch (j) { case 0: form = NumberFormat.getInstance(locales[i]); break; case 1: form = NumberFormat.getIntegerInstance(locales[i]); break; case 2: form = NumberFormat.getCurrencyInstance(locales[i]); break; default: form = NumberFormat.getPercentInstance(locales[i]); break; } if (form instanceof DecimalFormat) { System.out.print(": " + ((DecimalFormat) form).toPattern()); } System.out.print(" -> " + form.format(myNumber)); try { System.out.println(" -> " + form.parse(form.format(myNumber))); } catch (ParseException e) {} } }
Summary
Inherited constants |
---|
Public constructors | |
---|---|
DecimalFormat()
Creates a DecimalFormat using the default pattern and symbols
for the default |
|
DecimalFormat(String pattern)
Creates a DecimalFormat using the given pattern and the symbols
for the default |
|
DecimalFormat(String pattern, DecimalFormatSymbols symbols)
Creates a DecimalFormat using the given pattern and symbols. |
Public methods | |
---|---|
void
|
applyLocalizedPattern(String pattern)
Apply the given pattern to this Format object. |
void
|
applyPattern(String pattern)
Apply the given pattern to this Format object. |
Object
|
clone()
Standard override; no change in semantics. |
boolean
|
equals(Object obj)
Overrides equals |
final
StringBuffer
|
format(Object number, StringBuffer toAppendTo, FieldPosition pos)
Formats a number and appends the resulting text to the given string buffer. |
StringBuffer
|
format(double number, StringBuffer result, FieldPosition fieldPosition)
Formats a double to produce a string. |
StringBuffer
|
format(long number, StringBuffer result, FieldPosition fieldPosition)
Format a long to produce a string. |
AttributedCharacterIterator
|
formatToCharacterIterator(Object obj)
Formats an Object producing an |
Currency
|
getCurrency()
Gets the currency used by this decimal format when formatting currency values. |
DecimalFormatSymbols
|
getDecimalFormatSymbols()
Returns a copy of the decimal format symbols, which is generally not changed by the programmer or user. |
int
|
getGroupingSize()
Return the grouping size. |
int
|
getMaximumFractionDigits()
Gets the maximum number of digits allowed in the fraction portion of a number. |
int
|
getMaximumIntegerDigits()
Gets the maximum number of digits allowed in the integer portion of a number. |
int
|
getMinimumFractionDigits()
Gets the minimum number of digits allowed in the fraction portion of a number. |
int
|
getMinimumIntegerDigits()
Gets the minimum number of digits allowed in the integer portion of a number. |
int
|
getMultiplier()
Gets the multiplier for use in percent, per mille, and similar formats. |
String
|
getNegativePrefix()
Get the negative prefix. |
String
|
getNegativeSuffix()
Get the negative suffix. |
String
|
getPositivePrefix()
Get the positive prefix. |
String
|
getPositiveSuffix()
Get the positive suffix. |
RoundingMode
|
getRoundingMode()
Gets the |
int
|
hashCode()
Overrides hashCode |
boolean
|
isDecimalSeparatorAlwaysShown()
Allows you to get the behavior of the decimal separator with integers. |
boolean
|
isGroupingUsed()
Returns true if grouping is used in this format. |
boolean
|
isParseBigDecimal()
Returns whether the |
boolean
|
isParseIntegerOnly()
Returns true if this format will parse numbers as integers only. |
Number
|
parse(String text, ParsePosition pos)
Parses text from a string to produce a |
void
|
setCurrency(Currency currency)
Sets the currency used by this number format when formatting currency values. |
void
|
setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)
Sets the decimal format symbols, which is generally not changed by the programmer or user. |
void
|
setDecimalSeparatorAlwaysShown(boolean newValue)
Allows you to set the behavior of the decimal separator with integers. |
void
|
setGroupingSize(int newValue)
Set the grouping size. |
void
|
setGroupingUsed(boolean newValue)
Set whether or not grouping will be used in this format. |
void
|
setMaximumFractionDigits(int newValue)
Sets the maximum number of digits allowed in the fraction portion of a number. |
void
|
setMaximumIntegerDigits(int newValue)
Sets the maximum number of digits allowed in the integer portion of a number. |
void
|
setMinimumFractionDigits(int newValue)
Sets the minimum number of digits allowed in the fraction portion of a number. |
void
|
setMinimumIntegerDigits(int newValue)
Sets the minimum number of digits allowed in the integer portion of a number. |
void
|
setMultiplier(int newValue)
Sets the multiplier for use in percent, per mille, and similar formats. |
void
|
setNegativePrefix(String newValue)
Set the negative prefix. |
void
|
setNegativeSuffix(String newValue)
Set the negative suffix. |
void
|
setParseBigDecimal(boolean newValue)
Sets whether the |
void
|
setParseIntegerOnly(boolean value)
Sets whether or not numbers should be parsed as integers only. |
void
|
setPositivePrefix(String newValue)
Set the positive prefix. |
void
|
setPositiveSuffix(String newValue)
Set the positive suffix. |
void
|
setRoundingMode(RoundingMode roundingMode)
Sets the |
String
|
toLocalizedPattern()
Synthesizes a localized pattern string that represents the current state of this Format object. |
String
|
toPattern()
Synthesizes a pattern string that represents the current state of this Format object. |
Inherited methods | |
---|---|
Public constructors
DecimalFormat
public DecimalFormat ()
Creates a DecimalFormat using the default pattern and symbols
for the default FORMAT
locale.
This is a convenient way to obtain a
DecimalFormat when internationalization is not the main concern.
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.
DecimalFormat
public DecimalFormat (String pattern)
Creates a DecimalFormat using the given pattern and the symbols
for the default FORMAT
locale.
This is a convenient way to obtain a
DecimalFormat when internationalization is not the main concern.
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.
Parameters | |
---|---|
pattern |
String : a non-localized pattern string. |
Throws | |
---|---|
NullPointerException |
if pattern is null |
IllegalArgumentException |
if the given pattern is invalid. |
DecimalFormat
public DecimalFormat (String pattern, DecimalFormatSymbols symbols)
Creates a DecimalFormat using the given pattern and symbols. Use this constructor when you need to completely customize the behavior of the format.
To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getInstance or getCurrencyInstance. If you need only minor adjustments to a standard format, you can modify the format returned by a NumberFormat factory method.
Parameters | |
---|---|
pattern |
String : a non-localized pattern string |
symbols |
DecimalFormatSymbols : the set of symbols to be used |
Throws | |
---|---|
NullPointerException |
if any of the given arguments is null |
IllegalArgumentException |
if the given pattern is invalid |
Public methods
applyLocalizedPattern
public void applyLocalizedPattern (String pattern)
Apply the given pattern to this Format object. The pattern is assumed to be in a localized notation. A pattern is a short-hand specification for the various formatting properties. These properties can also be changed individually through the various setter methods.
There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon
Example "#,#00.0#"
→ 1,234.56
This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.
Example: "#,#00.0#;(#,#00.0#)"
for negatives in
parentheses.
In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.
Parameters | |
---|---|
pattern |
String : a new pattern |
Throws | |
---|---|
NullPointerException |
if pattern is null |
IllegalArgumentException |
if the given pattern is invalid. |
applyPattern
public void applyPattern (String pattern)
Apply the given pattern to this Format object. A pattern is a short-hand specification for the various formatting properties. These properties can also be changed individually through the various setter methods.
There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon
Example "#,#00.0#"
→ 1,234.56
This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.
Example: "#,#00.0#;(#,#00.0#)"
for negatives in
parentheses.
In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.
Parameters | |
---|---|
pattern |
String : a new pattern |
Throws | |
---|---|
NullPointerException |
if pattern is null |
IllegalArgumentException |
if the given pattern is invalid. |
clone
public Object clone ()
Standard override; no change in semantics.
Returns | |
---|---|
Object |
a clone of this instance. |
equals
public boolean equals (Object obj)
Overrides equals
Parameters | |
---|---|
obj |
Object : the reference object with which to compare. |
Returns | |
---|---|
boolean |
true if this object is the same as the obj
argument; false otherwise. |
format
public final StringBuffer format (Object number, StringBuffer toAppendTo, FieldPosition pos)
Formats a number and appends the resulting text to the given string
buffer.
The number can be of any subclass of Number
.
This implementation uses the maximum precision permitted.
Parameters | |
---|---|
number |
Object : the number to format |
toAppendTo |
StringBuffer : the StringBuffer to which the formatted
text is to be appended |
pos |
FieldPosition : keeps track on the position of the field within the
returned string. For example, for formatting a number
1234567.89 in Locale.US locale,
if the given fieldPosition is
NumberFormat#INTEGER_FIELD , the begin index
and end index of fieldPosition will be set
to 0 and 9, respectively for the output string
1,234,567.89 . |
Returns | |
---|---|
StringBuffer |
the value passed in as toAppendTo |
Throws | |
---|---|
IllegalArgumentException |
if number is
null or not an instance of Number . |
NullPointerException |
if toAppendTo or
pos is null |
ArithmeticException |
if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY |
See also:
format
public StringBuffer format (double number, StringBuffer result, FieldPosition fieldPosition)
Formats a double to produce a string.
Parameters | |
---|---|
number |
double : The double to format |
result |
StringBuffer : where the text is to be appended |
fieldPosition |
FieldPosition : keeps track on the position of the field within
the returned string. For example, for formatting
a number 1234567.89 in Locale.US
locale, if the given fieldPosition is
NumberFormat#INTEGER_FIELD , the begin index
and end index of fieldPosition will be set
to 0 and 9, respectively for the output string
1,234,567.89 . |
Returns | |
---|---|
StringBuffer |
The formatted number string |
Throws | |
---|---|
NullPointerException |
if result or
fieldPosition is null |
ArithmeticException |
if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY |
See also:
format
public StringBuffer format (long number, StringBuffer result, FieldPosition fieldPosition)
Format a long to produce a string.
Parameters | |
---|---|
number |
long : The long to format |
result |
StringBuffer : where the text is to be appended |
fieldPosition |
FieldPosition : keeps track on the position of the field within
the returned string. For example, for formatting
a number 123456789 in Locale.US
locale, if the given fieldPosition is
NumberFormat#INTEGER_FIELD , the begin index
and end index of fieldPosition will be set
to 0 and 11, respectively for the output string
123,456,789 . |
Returns | |
---|---|
StringBuffer |
The formatted number string |
Throws | |
---|---|
NullPointerException |
if result or
fieldPosition is null |
ArithmeticException |
if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY |
See also:
formatToCharacterIterator
public AttributedCharacterIterator formatToCharacterIterator (Object obj)
Formats an Object producing an AttributedCharacterIterator
.
You can use the returned AttributedCharacterIterator
to build the resulting String, as well as to determine information
about the resulting String.
Each attribute key of the AttributedCharacterIterator will be of type
NumberFormat.Field
, with the attribute value being the
same as the attribute key.
Parameters | |
---|---|
obj |
Object : The object to format |
Returns | |
---|---|
AttributedCharacterIterator |
AttributedCharacterIterator describing the formatted value. |
Throws | |
---|---|
NullPointerException |
if obj is null. |
IllegalArgumentException |
when the Format cannot format the given object. |
ArithmeticException |
if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY |
getCurrency
public Currency getCurrency ()
Gets the currency used by this decimal format when formatting
currency values.
The currency is obtained by calling
DecimalFormatSymbols.getCurrency
on this number format's symbols.
Returns | |
---|---|
Currency |
the currency used by this decimal format, or null |
getDecimalFormatSymbols
public DecimalFormatSymbols getDecimalFormatSymbols ()
Returns a copy of the decimal format symbols, which is generally not changed by the programmer or user.
Returns | |
---|---|
DecimalFormatSymbols |
a copy of the desired DecimalFormatSymbols |
See also:
getGroupingSize
public int getGroupingSize ()
Return the grouping size. Grouping size is the number of digits between
grouping separators in the integer portion of a number. For example,
in the number "123,456.78", the grouping size is 3. Grouping size of
zero designates that grouping is not used, which provides the same
formatting as if calling setGroupingUsed(false)
.
Returns | |
---|---|
int |
the grouping size |
getMaximumFractionDigits
public int getMaximumFractionDigits ()
Gets the maximum number of digits allowed in the fraction portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of the return value and
340 is used.
Returns | |
---|---|
int |
the maximum number of digits. |
See also:
getMaximumIntegerDigits
public int getMaximumIntegerDigits ()
Gets the maximum number of digits allowed in the integer portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of the return value and
309 is used.
Returns | |
---|---|
int |
the maximum number of digits |
See also:
getMinimumFractionDigits
public int getMinimumFractionDigits ()
Gets the minimum number of digits allowed in the fraction portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of the return value and
340 is used.
Returns | |
---|---|
int |
the minimum number of digits |
See also:
getMinimumIntegerDigits
public int getMinimumIntegerDigits ()
Gets the minimum number of digits allowed in the integer portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of the return value and
309 is used.
Returns | |
---|---|
int |
the minimum number of digits |
See also:
getMultiplier
public int getMultiplier ()
Gets the multiplier for use in percent, per mille, and similar formats.
Returns | |
---|---|
int |
the multiplier |
See also:
getNegativePrefix
public String getNegativePrefix ()
Get the negative prefix.
Examples: -123, ($123) (with negative suffix), sFr-123
Returns | |
---|---|
String |
the negative prefix |
getNegativeSuffix
public String getNegativeSuffix ()
Get the negative suffix.
Examples: -123%, ($123) (with positive suffixes)
Returns | |
---|---|
String |
the negative suffix |
getPositivePrefix
public String getPositivePrefix ()
Get the positive prefix.
Examples: +123, $123, sFr123
Returns | |
---|---|
String |
the positive prefix |
getPositiveSuffix
public String getPositiveSuffix ()
Get the positive suffix.
Example: 123%
Returns | |
---|---|
String |
the positive suffix |
getRoundingMode
public RoundingMode getRoundingMode ()
Gets the RoundingMode
used in this DecimalFormat.
Returns | |
---|---|
RoundingMode |
The RoundingMode used for this DecimalFormat. |
See also:
hashCode
public int hashCode ()
Overrides hashCode
Returns | |
---|---|
int |
a hash code value for this object. |
isDecimalSeparatorAlwaysShown
public boolean isDecimalSeparatorAlwaysShown ()
Allows you to get the behavior of the decimal separator with integers. (The decimal separator will always appear with decimals.)
Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345
Returns | |
---|---|
boolean |
true if the decimal separator is always shown;
false otherwise |
isGroupingUsed
public boolean isGroupingUsed ()
Returns true if grouping is used in this format. For example, in the English locale, with grouping on, the number 1234567 might be formatted as "1,234,567". The grouping separator as well as the size of each group is locale dependent and is determined by sub-classes of NumberFormat.
Returns | |
---|---|
boolean |
true if grouping is used;
false otherwise |
isParseBigDecimal
public boolean isParseBigDecimal ()
Returns whether the parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal
. The default value is false.
Returns | |
---|---|
boolean |
true if the parse method returns BigDecimal;
false otherwise |
See also:
isParseIntegerOnly
public boolean isParseIntegerOnly ()
Returns true if this format will parse numbers as integers only. For example in the English locale, with ParseIntegerOnly true, the string "1234." would be parsed as the integer value 1234 and parsing would stop at the "." character. Of course, the exact format accepted by the parse operation is locale dependent and determined by sub-classes of NumberFormat.
Returns | |
---|---|
boolean |
true if numbers should be parsed as integers only;
false otherwise |
parse
public Number parse (String text, ParsePosition pos)
Parses text from a string to produce a Number
.
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, the error index of pos
is set to the index of
the character where the error occurred, and null is returned.
The subclass returned depends on the value of isParseBigDecimal()
as well as on the string being parsed.
- If
isParseBigDecimal()
is false (the default), most integer values are returned asLong
objects, no matter how they are written:"17"
and"17.000"
both parse toLong(17)
. Values that cannot fit into aLong
are returned asDouble
s. This includes values with a fractional part, infinite values,NaN
, and the value -0.0.DecimalFormat
does not decide whether to return aDouble
or aLong
based on the presence of a decimal separator in the source string. Doing so would prevent integers that overflow the mantissa of a double, such as"-9,223,372,036,854,775,808.00"
, from being parsed accurately.Callers may use the
Number
methodsdoubleValue
,longValue
, etc., to obtain the type they want. - If
isParseBigDecimal()
is true, values are returned asBigDecimal
objects. The values are the ones constructed byBigDecimal.BigDecimal(String)
for corresponding strings in locale-independent format. The special cases negative and positive infinity and NaN are returned asDouble
instances holding the values of the correspondingDouble
constants.
DecimalFormat
parses all Unicode characters that represent
decimal digits, as defined by Character.digit()
. In
addition, DecimalFormat
also recognizes as digits the ten
consecutive characters starting with the localized zero digit defined in
the DecimalFormatSymbols
object.
Parameters | |
---|---|
text |
String : the string to be parsed |
pos |
ParsePosition : A ParsePosition object with index and error
index information as described above. |
Returns | |
---|---|
Number |
the parsed value, or null if the parse fails |
Throws | |
---|---|
NullPointerException |
if text or
pos is null. |
setCurrency
public void setCurrency (Currency currency)
Sets the currency used by this number format when formatting
currency values. This does not update the minimum or maximum
number of fraction digits used by the number format.
The currency is set by calling
DecimalFormatSymbols.setCurrency
on this number format's symbols.
Parameters | |
---|---|
currency |
Currency : the new currency to be used by this decimal format |
Throws | |
---|---|
NullPointerException |
if currency is null |
setDecimalFormatSymbols
public void setDecimalFormatSymbols (DecimalFormatSymbols newSymbols)
Sets the decimal format symbols, which is generally not changed by the programmer or user.
Parameters | |
---|---|
newSymbols |
DecimalFormatSymbols : desired DecimalFormatSymbols |
See also:
setDecimalSeparatorAlwaysShown
public void setDecimalSeparatorAlwaysShown (boolean newValue)
Allows you to set the behavior of the decimal separator with integers. (The decimal separator will always appear with decimals.)
Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345
Parameters | |
---|---|
newValue |
boolean : true if the decimal separator is always shown;
false otherwise |
setGroupingSize
public void setGroupingSize (int newValue)
Set the grouping size. Grouping size is the number of digits between
grouping separators in the integer portion of a number. For example,
in the number "123,456.78", the grouping size is 3. Grouping size of
zero designates that grouping is not used, which provides the same
formatting as if calling setGroupingUsed(false)
.
The value passed in is converted to a byte, which may lose information.
Values that are negative or greater than
Byte.MAX_VALUE
, will throw an
IllegalArgumentException
.
Parameters | |
---|---|
newValue |
int : the new grouping size |
Throws | |
---|---|
IllegalArgumentException |
if newValue is negative or
greater than Byte.MAX_VALUE |
setGroupingUsed
public void setGroupingUsed (boolean newValue)
Set whether or not grouping will be used in this format.
Parameters | |
---|---|
newValue |
boolean : true if grouping is used;
false otherwise |
setMaximumFractionDigits
public void setMaximumFractionDigits (int newValue)
Sets the maximum number of digits allowed in the fraction portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of newValue
and
340 is used. Negative input values are replaced with 0.
Parameters | |
---|---|
newValue |
int : the maximum number of fraction digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted. |
setMaximumIntegerDigits
public void setMaximumIntegerDigits (int newValue)
Sets the maximum number of digits allowed in the integer portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of newValue
and
309 is used. Negative input values are replaced with 0.
Parameters | |
---|---|
newValue |
int : the maximum number of integer digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted. |
setMinimumFractionDigits
public void setMinimumFractionDigits (int newValue)
Sets the minimum number of digits allowed in the fraction portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of newValue
and
340 is used. Negative input values are replaced with 0.
Parameters | |
---|---|
newValue |
int : the minimum number of fraction digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted. |
setMinimumIntegerDigits
public void setMinimumIntegerDigits (int newValue)
Sets the minimum number of digits allowed in the integer portion of a
number.
For formatting numbers other than BigInteger
and
BigDecimal
objects, the lower of newValue
and
309 is used. Negative input values are replaced with 0.
Parameters | |
---|---|
newValue |
int : the minimum number of integer digits to be shown; if
less than zero, then zero is used. The concrete subclass may enforce an
upper limit to this value appropriate to the numeric type being formatted. |
setMultiplier
public void setMultiplier (int newValue)
Sets the multiplier for use in percent, per mille, and similar formats. For a percent format, set the multiplier to 100 and the suffixes to have '%' (for Arabic, use the Arabic percent sign). For a per mille format, set the multiplier to 1000 and the suffixes to have '\u2030'.
Example: with multiplier 100, 1.23 is formatted as "123", and "123" is parsed into 1.23.
Parameters | |
---|---|
newValue |
int : the new multiplier |
See also:
setNegativePrefix
public void setNegativePrefix (String newValue)
Set the negative prefix.
Examples: -123, ($123) (with negative suffix), sFr-123
Parameters | |
---|---|
newValue |
String : the new negative prefix |
setNegativeSuffix
public void setNegativeSuffix (String newValue)
Set the negative suffix.
Examples: 123%
Parameters | |
---|---|
newValue |
String : the new negative suffix |
setParseBigDecimal
public void setParseBigDecimal (boolean newValue)
Sets whether the parse(java.lang.String, java.text.ParsePosition)
method returns BigDecimal
.
Parameters | |
---|---|
newValue |
boolean : true if the parse method returns BigDecimal;
false otherwise |
See also:
setParseIntegerOnly
public void setParseIntegerOnly (boolean value)
Sets whether or not numbers should be parsed as integers only.
Parameters | |
---|---|
value |
boolean : true if numbers should be parsed as integers only;
false otherwise |
setPositivePrefix
public void setPositivePrefix (String newValue)
Set the positive prefix.
Examples: +123, $123, sFr123
Parameters | |
---|---|
newValue |
String : the new positive prefix |
setPositiveSuffix
public void setPositiveSuffix (String newValue)
Set the positive suffix.
Example: 123%
Parameters | |
---|---|
newValue |
String : the new positive suffix |
setRoundingMode
public void setRoundingMode (RoundingMode roundingMode)
Sets the RoundingMode
used in this DecimalFormat.
Parameters | |
---|---|
roundingMode |
RoundingMode : The RoundingMode to be used |
Throws | |
---|---|
NullPointerException |
if roundingMode is null. |
See also:
toLocalizedPattern
public String toLocalizedPattern ()
Synthesizes a localized pattern string that represents the current state of this Format object.
Returns | |
---|---|
String |
a localized pattern string |
See also:
toPattern
public String toPattern ()
Synthesizes a pattern string that represents the current state of this Format object.
Returns | |
---|---|
String |
a pattern string |
See also: